From 95fcf1251e56a98415cfe26ac9bb6c327c177a5a Mon Sep 17 00:00:00 2001
From: Siarhei Fedartsou <siarhei.fedartsou@gmail.com>
Date: Sat, 1 Mar 2025 18:17:44 +0100
Subject: [PATCH 1/3] Modernize codebase

---
 integration/address_matching.js               | 100 +++---
 integration/admin_abbreviations.js            |  16 +-
 integration/admin_matching.js                 |  26 +-
 integration/analyzer_peliasAdmin.js           |  72 ++--
 integration/analyzer_peliasHousenumber.js     |  28 +-
 .../analyzer_peliasIndexOneEdgeGram.js        |  92 ++---
 integration/analyzer_peliasPhrase.js          | 128 +++----
 integration/analyzer_peliasQuery.js           |  66 ++--
 integration/analyzer_peliasStreet.js          |  96 ++---
 integration/analyzer_peliasZip.js             |  28 +-
 .../autocomplete_abbreviated_street_names.js  |  18 +-
 ...ocomplete_directional_synonym_expansion.js |  68 ++--
 .../autocomplete_street_synonym_expansion.js  |  68 ++--
 integration/bounding_box.js                   |  18 +-
 integration/dynamic_templates.js              |  18 +-
 integration/multi_token_synonyms.js           |  14 +-
 integration/run.js                            |  22 +-
 .../source_layer_sourceid_filtering.js        |  48 +--
 integration/validate.js                       |   8 +-
 mappings/document.js                          |   2 +-
 scripts/cli.js                                |   2 +-
 scripts/drop_index.js                         |   4 +-
 scripts/info.js                               |   6 +-
 scripts/list_analyzers.js                     |  12 +-
 scripts/output_mapping.js                     |   2 +-
 scripts/update_settings.js                    |  16 +-
 settings.js                                   |   4 +-
 synonyms/country_codes/generate.js            |   8 +-
 test/compile.js                               |  40 +--
 test/configValidation.js                      |  36 +-
 test/document.js                              |  84 ++---
 test/partial-admin.js                         |  26 +-
 test/partial-centroid.js                      |  14 +-
 test/partial-hash.js                          |  18 +-
 test/partial-keyword.js                       |  22 +-
 test/run.js                                   |   9 +-
 test/settings.js                              | 334 +++++++++---------
 test/synonyms/parser.js                       |  24 +-
 38 files changed, 791 insertions(+), 806 deletions(-)

diff --git a/integration/address_matching.js b/integration/address_matching.js
index 4ea5e23d..4eab55b2 100644
--- a/integration/address_matching.js
+++ b/integration/address_matching.js
@@ -6,14 +6,14 @@ const getTotalHits = require('./_hits_total_helper');
 
 module.exports.tests = {};
 
-module.exports.tests.functional = function(test, common){
-  test( 'functional', function(t){
+module.exports.tests.functional = (test, common) => {
+  test( 'functional', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index some docs
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1', body: { address_parts: {
@@ -25,7 +25,7 @@ module.exports.tests.functional = function(test, common){
       }, done );
     });
 
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '2', body: { address_parts: {
@@ -37,7 +37,7 @@ module.exports.tests.functional = function(test, common){
       }, done );
     });
 
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '3', body: { address_parts: {
@@ -49,7 +49,7 @@ module.exports.tests.functional = function(test, common){
       }, done );
     });
 
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '4', body: { address_parts: {
@@ -62,13 +62,13 @@ module.exports.tests.functional = function(test, common){
     });
 
     // search by street number
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { bool: { must: [
           { match: { 'address_parts.number': 30 } }
         ]}}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'match street number' );
         done();
@@ -76,13 +76,13 @@ module.exports.tests.functional = function(test, common){
     });
 
     // search by street name - case insensitive
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { bool: { must: [
           { match_phrase: { 'address_parts.street': 'west 26th street' } }
         ]}}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 2, 'match street name' );
         done();
@@ -90,13 +90,13 @@ module.exports.tests.functional = function(test, common){
     });
 
     // search by street name - using abbreviations
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { bool: { must: [
           { match_phrase: { 'address_parts.street': 'W 26th ST' } }
         ]}}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 2, 'match street name - abbr' );
         done();
@@ -104,13 +104,13 @@ module.exports.tests.functional = function(test, common){
     });
 
     // search by zip - numeric zip
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { bool: { must: [
           { match: { 'address_parts.zip': '10010' } }
         ]}}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 3, 'match zip - numeric' );
         done();
@@ -118,13 +118,13 @@ module.exports.tests.functional = function(test, common){
     });
 
     // search by zip - string zip
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { bool: { must: [
           { match: { 'address_parts.zip': 'e24dn' } }
         ]}}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'match zip - string' );
         done();
@@ -132,13 +132,13 @@ module.exports.tests.functional = function(test, common){
     });
 
     // search by zip - numeric zip - with punctuation
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { bool: { must: [
           { match: { 'address_parts.zip': '100-10' } }
         ]}}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 3, 'match zip - numeric - punct' );
         done();
@@ -146,13 +146,13 @@ module.exports.tests.functional = function(test, common){
     });
 
     // search by zip - numeric zip - with whitespace
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { bool: { must: [
           { match: { 'address_parts.zip': '10 0 10' } }
         ]}}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 3, 'match zip - numeric - whitespace' );
         done();
@@ -160,13 +160,13 @@ module.exports.tests.functional = function(test, common){
     });
 
     // search by zip - string zip - with punctuation
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { bool: { must: [
           { match: { 'address_parts.zip': 'E2-4DN' } }
         ]}}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'match zip - string - punct' );
         done();
@@ -174,13 +174,13 @@ module.exports.tests.functional = function(test, common){
     });
 
     // search by zip - string zip - with whitespace
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { bool: { must: [
           { match: { 'address_parts.zip': 'E2  4DN' } }
         ]}}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'match zip - string - whitespace' );
         done();
@@ -192,8 +192,8 @@ module.exports.tests.functional = function(test, common){
 };
 
 
-module.exports.tests.venue_vs_address = function(test, common){
-  test( 'venue_vs_address', function(t){
+module.exports.tests.venue_vs_address = (test, common) => {
+  test( 'venue_vs_address', t => {
     // This test shows that partial matching addresses score higher than exact matching
     // venues with the same name.
 
@@ -204,11 +204,11 @@ module.exports.tests.venue_vs_address = function(test, common){
     // Unfortunately there seems to be no easy way of fixing this, it's an artifact of us
     // storing the street names in the name.default field.
 
-    var suite = new Suite( common.clientOpts, common.create );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index a venue
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1', body: {
@@ -220,32 +220,30 @@ module.exports.tests.venue_vs_address = function(test, common){
 
     // index multiple streets, having many in the index is important
     // because it influences the 'norms' and TF/IDF scoring
-    const testFactory = function(i){
-      return function( done ){
-        let id = i + 100; // id offset
-        suite.client.index({
-          index: suite.props.index,
-          id: String(id),
-          body: {
-            name: { default: `${id} Union Square` },
-            phrase: { default: `${id} Union Square` },
-            address_parts: {
-              number: String(i),
-              street: 'Union Square'
-            }
+    const testFactory = i => done => {
+      let id = i + 100; // id offset
+      suite.client.index({
+        index: suite.props.index,
+        id: String(id),
+        body: {
+          name: { default: `${id} Union Square` },
+          phrase: { default: `${id} Union Square` },
+          address_parts: {
+            number: String(i),
+            street: 'Union Square'
           }
-        }, done);
-      };
+        }
+      }, done);
     };
 
     const TOTAL_ADDRESS_DOCS=9;
-    for( var i=0; i<TOTAL_ADDRESS_DOCS; i++ ){
+    for( let i=0; i<TOTAL_ADDRESS_DOCS; i++ ){
       suite.action( testFactory(i) );
     }
 
     // autocomplete-style query to assert which result is scored higher,
     // the exact matching venue, or the partial matching address.
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         searchType: 'dfs_query_then_fetch',
@@ -289,7 +287,7 @@ module.exports.tests.venue_vs_address = function(test, common){
             }
           }
         }
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), TOTAL_ADDRESS_DOCS+1, 'matched all docs' );
         t.equal( res.hits.hits[TOTAL_ADDRESS_DOCS]._id, '1', 'exact name match first' );
@@ -301,13 +299,13 @@ module.exports.tests.venue_vs_address = function(test, common){
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('address matching: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/admin_abbreviations.js b/integration/admin_abbreviations.js
index 20369180..66b64a5f 100644
--- a/integration/admin_abbreviations.js
+++ b/integration/admin_abbreviations.js
@@ -9,10 +9,10 @@ module.exports.tests = {};
  * include a synonym mapping for country code abbreviations
  * which maps between alpha2 and alpha3 variants.
 */
-module.exports.tests.synonyms = function (test, common) {
-  test('synonyms - alpha3 does not share a prefix with alpha2', function (t) {
+module.exports.tests.synonyms = (test, common) => {
+  test('synonyms - alpha3 does not share a prefix with alpha2', t => {
 
-    var suite = new Suite(common.clientOpts, common.create);
+    const suite = new Suite(common.clientOpts, common.create);
     suite.action(done => setTimeout(done, 500)); // wait for es to bring some shards up
 
     // index document 1 with country_a='MEX'
@@ -132,9 +132,9 @@ module.exports.tests.synonyms = function (test, common) {
     suite.run(t.end);
   });
 
-  test('synonyms - alpha3 shares a prefix with alpha2', function (t) {
+  test('synonyms - alpha3 shares a prefix with alpha2', t => {
 
-    var suite = new Suite(common.clientOpts, common.create);
+    const suite = new Suite(common.clientOpts, common.create);
     suite.action(done => setTimeout(done, 500)); // wait for es to bring some shards up
 
     // index document 1 with country_a='NZL'
@@ -254,9 +254,9 @@ module.exports.tests.synonyms = function (test, common) {
     suite.run(t.end);
   });
 
-  test('synonyms - additional synonyms do not increase field length', function (t) {
+  test('synonyms - additional synonyms do not increase field length', t => {
 
-    var suite = new Suite(common.clientOpts, common.create);
+    const suite = new Suite(common.clientOpts, common.create);
     suite.action(done => setTimeout(done, 500)); // wait for es to bring some shards up
 
     // index document 1 with country_a='NZL'
@@ -329,7 +329,7 @@ module.exports.all = (tape, common) => {
     return tape('multi token synonyms: ' + name, testFunction);
   }
 
-  for (var testCase in module.exports.tests) {
+  for (const testCase in module.exports.tests) {
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/admin_matching.js b/integration/admin_matching.js
index 7d1de3b0..ca72f099 100644
--- a/integration/admin_matching.js
+++ b/integration/admin_matching.js
@@ -6,14 +6,14 @@ const getTotalHits = require('./_hits_total_helper');
 
 module.exports.tests = {};
 
-module.exports.tests.functional = function(test, common){
-  test( 'functional', function(t){
+module.exports.tests.functional = (test, common) => {
+  test( 'functional', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index a document with all admin values
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1', body: {
@@ -42,11 +42,11 @@ module.exports.tests.functional = function(test, common){
     });
 
     // search by country
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: { 'parent.country': 'Test Country' } } }
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -54,11 +54,11 @@ module.exports.tests.functional = function(test, common){
     });
 
     // search by country_a
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: { 'parent.country_a': 'TestCountry' } } }
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -66,11 +66,11 @@ module.exports.tests.functional = function(test, common){
     });
 
     // search by country_id
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: { 'parent.country_id': '100' } } }
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -84,13 +84,13 @@ module.exports.tests.functional = function(test, common){
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('admin matching: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/analyzer_peliasAdmin.js b/integration/analyzer_peliasAdmin.js
index 22ec63f8..cdc04cd2 100644
--- a/integration/analyzer_peliasAdmin.js
+++ b/integration/analyzer_peliasAdmin.js
@@ -1,17 +1,15 @@
 // validate analyzer is behaving as expected
 
-var tape = require('tape'),
-    Suite = require('../test/elastictest/Suite'),
-    punctuation = require('../punctuation');
+const tape = require('tape'), Suite = require('../test/elastictest/Suite'), punctuation = require('../punctuation');
 
 module.exports.tests = {};
 
-module.exports.tests.analyze = function(test, common){
-  test( 'analyze', function(t){
+module.exports.tests.analyze = (test, common) => {
+  test( 'analyze', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasAdmin' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasAdmin' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'lowercase', 'F', ['f']);
     assertAnalysis( 'asciifolding', 'é', ['e']);
@@ -30,12 +28,12 @@ module.exports.tests.analyze = function(test, common){
   });
 };
 
-module.exports.tests.functional = function(test, common){
-  test( 'functional', function(t){
+module.exports.tests.functional = (test, common) => {
+  test( 'functional', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasAdmin' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasAdmin' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'country', 'Trinidad and Tobago', [
       'trinidad', 'and', 'tobago'
@@ -68,12 +66,12 @@ module.exports.tests.functional = function(test, common){
   });
 };
 
-module.exports.tests.synonyms = function(test, common){
-  test( 'synonyms', function(t){
+module.exports.tests.synonyms = (test, common) => {
+  test( 'synonyms', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasAdmin' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasAdmin' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'place', 'Saint-Louis-du-Ha! Ha!', [
       '0:saint', '0:st', '1:louis', '2:du', '3:ha', '4:ha'
@@ -95,12 +93,12 @@ module.exports.tests.synonyms = function(test, common){
   });
 };
 
-module.exports.tests.tokenizer = function(test, common){
-  test( 'tokenizer', function(t){
+module.exports.tests.tokenizer = (test, common) => {
+  test( 'tokenizer', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasAdmin' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasAdmin' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     const expected = ['0:trinidad', '1:tobago'];
 
@@ -123,22 +121,22 @@ module.exports.tests.tokenizer = function(test, common){
 };
 
 // @see: https://github.com/pelias/api/issues/600
-module.exports.tests.unicode = function(test, common){
-  test( 'normalization', function(t){
+module.exports.tests.unicode = (test, common) => {
+  test( 'normalization', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasAdmin' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasAdmin' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
-    var latin_large_letter_e_with_acute = String.fromCodePoint(0x00C9);
-    var latin_small_letter_e_with_acute = String.fromCodePoint(0x00E9);
-    var combining_acute_accent = String.fromCodePoint(0x0301);
-    var latin_large_letter_e = String.fromCodePoint(0x0045);
-    var latin_small_letter_e = String.fromCodePoint(0x0065);
+    const latin_large_letter_e_with_acute = String.fromCodePoint(0x00C9);
+    const latin_small_letter_e_with_acute = String.fromCodePoint(0x00E9);
+    const combining_acute_accent = String.fromCodePoint(0x0301);
+    const latin_large_letter_e = String.fromCodePoint(0x0045);
+    const latin_small_letter_e = String.fromCodePoint(0x0065);
 
     // Chambéry (both forms appear the same)
-    var composed = "Chamb" + latin_small_letter_e_with_acute + "ry";
-    var decomposed = "Chamb" + combining_acute_accent + latin_small_letter_e + "ry";
+    let composed = "Chamb" + latin_small_letter_e_with_acute + "ry";
+    let decomposed = "Chamb" + combining_acute_accent + latin_small_letter_e + "ry";
 
     assertAnalysis( 'composed', composed, ['chambery'] );
     assertAnalysis( 'decomposed', decomposed, ['chambery'] );
@@ -154,13 +152,13 @@ module.exports.tests.unicode = function(test, common){
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('peliasAdmin: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/analyzer_peliasHousenumber.js b/integration/analyzer_peliasHousenumber.js
index d24962cb..0b726574 100644
--- a/integration/analyzer_peliasHousenumber.js
+++ b/integration/analyzer_peliasHousenumber.js
@@ -1,17 +1,15 @@
 // validate analyzer is behaving as expected
 
-var tape = require('tape'),
-    Suite = require('../test/elastictest/Suite'),
-    punctuation = require('../punctuation');
+const tape = require('tape'), Suite = require('../test/elastictest/Suite'), punctuation = require('../punctuation');
 
 module.exports.tests = {};
 
-module.exports.tests.analyze = function(test, common){
-  test( 'analyze', function(t){
+module.exports.tests.analyze = (test, common) => {
+  test( 'analyze', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasHousenumber' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasHousenumber' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'keyword', '100 100', ['100','100']);
     assertAnalysis( 'numeric', '1a', ['1'] );
@@ -20,12 +18,12 @@ module.exports.tests.analyze = function(test, common){
   });
 };
 
-module.exports.tests.functional = function(test, common){
-  test( 'functional', function(t){
+module.exports.tests.functional = (test, common) => {
+  test( 'functional', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasHousenumber' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasHousenumber' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'apt no (generic)', '101a', [ '101' ]);
 
@@ -38,13 +36,13 @@ module.exports.tests.functional = function(test, common){
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('peliasHousenumber: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/analyzer_peliasIndexOneEdgeGram.js b/integration/analyzer_peliasIndexOneEdgeGram.js
index 523c092f..2a3448cf 100644
--- a/integration/analyzer_peliasIndexOneEdgeGram.js
+++ b/integration/analyzer_peliasIndexOneEdgeGram.js
@@ -7,12 +7,12 @@ const tape = require('tape'),
 
 module.exports.tests = {};
 
-module.exports.tests.analyze = function(test, common){
-  test( 'analyze', function(t){
+module.exports.tests.analyze = (test, common) => {
+  test( 'analyze', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasIndexOneEdgeGram' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasIndexOneEdgeGram' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'lowercase', 'F', ['f']);
     assertAnalysis( 'asciifolding', 'á', ['a']);
@@ -101,12 +101,12 @@ module.exports.tests.analyze = function(test, common){
 
 // address suffix expansions should only performed in a way that is
 // safe for 'partial tokens'.
-module.exports.tests.address_suffix_expansions = function(test, common){
-  test( 'address suffix expansions', function(t){
+module.exports.tests.address_suffix_expansions = (test, common) => {
+  test( 'address suffix expansions', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasIndexOneEdgeGram' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasIndexOneEdgeGram' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'safe expansions', 'aly', [
       '0:a', '0:al', '0:aly', '0:all', '0:alle', '0:alley'
@@ -131,12 +131,12 @@ module.exports.tests.address_suffix_expansions = function(test, common){
 };
 
 // stop words should be disabled so that the entire street prefix is indexed as ngrams
-module.exports.tests.stop_words = function(test, common){
-  test( 'stop words', function(t){
+module.exports.tests.stop_words = (test, common) => {
+  test( 'stop words', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasIndexOneEdgeGram' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasIndexOneEdgeGram' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'street suffix', 'AB street', [
       '0:a', '0:ab',
@@ -152,12 +152,12 @@ module.exports.tests.stop_words = function(test, common){
   });
 };
 
-module.exports.tests.functional = function(test, common){
-  test( 'functional', function(t){
+module.exports.tests.functional = (test, common) => {
+  test( 'functional', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasIndexOneEdgeGram' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasIndexOneEdgeGram' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis('country', 'Trinidad and Tobago', [
       '0:t', '0:tr', '0:tri', '0:trin', '0:trini', '0:trinid', '0:trinida', '0:trinidad',
@@ -178,12 +178,12 @@ module.exports.tests.functional = function(test, common){
 };
 
 // unique token filter should only remove duplicate tokens at same position
-module.exports.tests.unique = function(test, common){
-  test( 'unique', function(t){
+module.exports.tests.unique = (test, common) => {
+  test( 'unique', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasIndexOneEdgeGram' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasIndexOneEdgeGram' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // if 'only_on_same_position' is not used the '1:a' token is erroneously removed
     assertAnalysis( 'unique', 'a ab', [ '0:a', '1:a', '1:ab' ]);
@@ -192,12 +192,12 @@ module.exports.tests.unique = function(test, common){
   });
 };
 
-module.exports.tests.address = function(test, common){
-  test( 'address', function(t){
+module.exports.tests.address = (test, common) => {
+  test( 'address', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasIndexOneEdgeGram' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasIndexOneEdgeGram' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'address', '101 mapzen place', [
       '0:1', '0:10', '0:101',
@@ -224,22 +224,22 @@ module.exports.tests.address = function(test, common){
 };
 
 // @see: https://github.com/pelias/api/issues/600
-module.exports.tests.unicode = function(test, common){
-  test( 'normalization', function(t){
+module.exports.tests.unicode = (test, common) => {
+  test( 'normalization', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasIndexOneEdgeGram' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasIndexOneEdgeGram' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
-    var latin_large_letter_e_with_acute = String.fromCodePoint(0x00C9);
-    var latin_small_letter_e_with_acute = String.fromCodePoint(0x00E9);
-    var combining_acute_accent = String.fromCodePoint(0x0301);
-    var latin_large_letter_e = String.fromCodePoint(0x0045);
-    var latin_small_letter_e = String.fromCodePoint(0x0065);
+    const latin_large_letter_e_with_acute = String.fromCodePoint(0x00C9);
+    const latin_small_letter_e_with_acute = String.fromCodePoint(0x00E9);
+    const combining_acute_accent = String.fromCodePoint(0x0301);
+    const latin_large_letter_e = String.fromCodePoint(0x0045);
+    const latin_small_letter_e = String.fromCodePoint(0x0065);
 
     // Chambéry (both forms appear the same)
-    var composed = "Chamb" + latin_small_letter_e_with_acute + "ry";
-    var decomposed = "Chamb" + combining_acute_accent + latin_small_letter_e + "ry"
+    let composed = "Chamb" + latin_small_letter_e_with_acute + "ry";
+    let decomposed = "Chamb" + combining_acute_accent + latin_small_letter_e + "ry"
 
     assertAnalysis( 'composed', composed, [
       '0:c', '0:ch', '0:cha', '0:cham', '0:chamb', '0:chambe', '0:chamber', '0:chambery'
@@ -249,8 +249,8 @@ module.exports.tests.unicode = function(test, common){
     ] );
 
     // Één (both forms appear the same)
-    var composed = latin_large_letter_e_with_acute + latin_small_letter_e_with_acute + "n";
-    var decomposed = combining_acute_accent + latin_large_letter_e + combining_acute_accent + latin_small_letter_e + "n"
+    composed = latin_large_letter_e_with_acute + latin_small_letter_e_with_acute + "n";
+    decomposed = combining_acute_accent + latin_large_letter_e + combining_acute_accent + latin_small_letter_e + "n"
 
     assertAnalysis('composed', composed, ['0:e', '0:ee', '0:een']);
     assertAnalysis('decomposed', decomposed, ['0:e', '0:ee', '0:een']);
@@ -259,13 +259,13 @@ module.exports.tests.unicode = function(test, common){
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('peliasIndexOneEdgeGram: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/analyzer_peliasPhrase.js b/integration/analyzer_peliasPhrase.js
index d87a9fe2..21090bfd 100644
--- a/integration/analyzer_peliasPhrase.js
+++ b/integration/analyzer_peliasPhrase.js
@@ -7,12 +7,12 @@ const getTotalHits = require('./_hits_total_helper');
 
 module.exports.tests = {};
 
-module.exports.tests.analyze = function(test, common){
-  test( 'analyze', function(t){
+module.exports.tests.analyze = (test, common) => {
+  test( 'analyze', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasPhrase' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasPhrase' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'lowercase', 'F', ['f']);
     assertAnalysis( 'asciifolding', 'é', ['e']);
@@ -48,7 +48,7 @@ module.exports.tests.analyze = function(test, common){
     assertAnalysis( 'punctuation', punctuation.all.join(''), ['0:&', '0:and', '0:und'] );
     assertAnalysis( 'punctuation', 'Hawai‘i', ['hawaii'] );
     assertAnalysis( 'punctuation - « in between', '«res»pub«lika»', ['respublika'] );
- 
+
     assertAnalysis( 'british_american_english', 'town theatre', ['0:town', '1:theatre', '1:theater'] );
     assertAnalysis( 'british_american_english', 'town theater', ['0:town', '1:theater', '1:theatre'] );
 
@@ -56,12 +56,12 @@ module.exports.tests.analyze = function(test, common){
   });
 };
 
-module.exports.tests.functional = function(test, common){
-  test( 'functional', function(t){
+module.exports.tests.functional = (test, common) => {
+  test( 'functional', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasPhrase' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasPhrase' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'country', 'Trinidad and Tobago', [
       '0:trinidad', '1:and', '1:&', '2:tobago'
@@ -76,26 +76,26 @@ module.exports.tests.functional = function(test, common){
     ]);
 
     // both terms should map to same tokens
-    var expected1 = [ '0:325', '1:n', '1:north', '2:12', '3:st', '3:street' ];
-    var expected2 = [ '0:325', '1:north', '1:n', '2:12', '3:street', '3:st' ];
+    const expected1 = [ '0:325', '1:n', '1:north', '2:12', '3:st', '3:street' ];
+    const expected2 = [ '0:325', '1:north', '1:n', '2:12', '3:street', '3:st' ];
     assertAnalysis( 'address', '325 N 12th St', expected1 );
     assertAnalysis( 'address', '325 North 12th Street', expected2 );
 
     // both terms should map to same tokens
-    var expected3 = [ '0:13509', '1:colfax', '2:ave', '2:avenue', '2:av', '3:s', '3:south' ];
-    var expected4 = [ '0:13509', '1:colfax', '2:avenue', '2:ave', '2:av', '3:south', '3:s' ];
+    const expected3 = [ '0:13509', '1:colfax', '2:ave', '2:avenue', '2:av', '3:s', '3:south' ];
+    const expected4 = [ '0:13509', '1:colfax', '2:avenue', '2:ave', '2:av', '3:south', '3:s' ];
     assertAnalysis( 'address', '13509 Colfax Ave S', expected3 );
     assertAnalysis( 'address', '13509 Colfax Avenue South', expected4 );
 
     // both terms should map to same tokens
-    var expected5 = [ '0:100', '1:s', '1:south', '2:lake', '2:lk', '3:dr', '3:drive' ];
-    var expected6 = [ '0:100', '1:south', '1:s', '2:lake', '2:lk', '3:drive', '3:dr' ];
+    const expected5 = [ '0:100', '1:s', '1:south', '2:lake', '2:lk', '3:dr', '3:drive' ];
+    const expected6 = [ '0:100', '1:south', '1:s', '2:lake', '2:lk', '3:drive', '3:dr' ];
     assertAnalysis( 'address', '100 S Lake Dr', expected5 );
     assertAnalysis( 'address', '100 South Lake Drive', expected6 );
 
     // both terms should map to same tokens
-    var expected7 = [ '0:100', '1:northwest', '1:nw', '2:highway', '2:hwy' ];
-    var expected8 = [ '0:100', '1:nw', '1:northwest', '2:hwy', '2:highway' ];
+    const expected7 = [ '0:100', '1:northwest', '1:nw', '2:highway', '2:hwy' ];
+    const expected8 = [ '0:100', '1:nw', '1:northwest', '2:hwy', '2:highway' ];
     assertAnalysis( 'address', '100 northwest highway', expected7 );
     assertAnalysis( 'address', '100 nw hwy', expected8 );
 
@@ -103,14 +103,14 @@ module.exports.tests.functional = function(test, common){
   });
 };
 
-module.exports.tests.tokenizer = function(test, common){
-  test( 'tokenizer', function(t){
+module.exports.tests.tokenizer = (test, common) => {
+  test( 'tokenizer', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasPhrase' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasPhrase' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
-    var expected = [ '0:bedell', '1:street', '1:st', '2:133', '3:avenue', '3:ave', '3:av' ];
+    const expected = [ '0:bedell', '1:street', '1:st', '2:133', '3:avenue', '3:ave', '3:av' ];
 
     // specify 2 streets with a delimeter
     assertAnalysis( 'forward slash', 'Bedell Street/133rd Avenue',   expected );
@@ -129,12 +129,12 @@ module.exports.tests.tokenizer = function(test, common){
 
 // @ref: https://www.elastic.co/guide/en/elasticsearch/guide/current/phrase-matching.html
 // @ref: https://www.elastic.co/guide/en/elasticsearch/guide/current/slop.html
-module.exports.tests.slop = function(test, common){
-  test( 'slop', function(t){
+module.exports.tests.slop = (test, common) => {
+  test( 'slop', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasPhrase' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasPhrase' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // no index-time slop operations performed
     assertAnalysis( 'place', 'Lake Cayuga', [ 'lake', 'cayuga' ]);
@@ -147,15 +147,15 @@ module.exports.tests.slop = function(test, common){
 // balance scoring for similar terms 'Lake Cayuga', 'Cayuga Lake' and '7991 Lake Cayuga Dr'
 // @ref: https://www.elastic.co/guide/en/elasticsearch/guide/current/phrase-matching.html
 // @ref: https://www.elastic.co/guide/en/elasticsearch/guide/current/slop.html
-module.exports.tests.slop_query = function(test, common){
-  test( 'slop query', function(t){
+module.exports.tests.slop_query = (test, common) => {
+  test( 'slop query', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasPhrase' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasPhrase' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index 'Lake Cayuga'
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1',
@@ -164,7 +164,7 @@ module.exports.tests.slop_query = function(test, common){
     });
 
     // index 'Cayuga Lake'
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '2',
@@ -173,7 +173,7 @@ module.exports.tests.slop_query = function(test, common){
     });
 
     // index '7991 Lake Cayuga Dr'
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '3',
@@ -209,15 +209,15 @@ module.exports.tests.slop_query = function(test, common){
       };
     }
 
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         type: config.schema.typeName,
         searchType: 'dfs_query_then_fetch',
         body: buildQuery('Lake Cayuga')
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( getTotalHits(res.hits), 3 );
-        var hits = res.hits.hits;
+        const hits = res.hits.hits;
 
         t.equal( hits[0]._source.name.default, 'Lake Cayuga' );
 
@@ -240,14 +240,14 @@ module.exports.tests.slop_query = function(test, common){
 };
 
 // test the minimum amount of slop required to retrieve address documents
-module.exports.tests.slop = function(test, common){
-  test( 'slop', function(t){
+module.exports.tests.slop = (test, common) => {
+  test( 'slop', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index a document
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1',
@@ -259,7 +259,7 @@ module.exports.tests.slop = function(test, common){
     // in this case we require a slop of 3 to return the same
     // record with the street number and street name reversed.
     // (as is common in European countries, such as Germany).
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         searchType: 'dfs_query_then_fetch',
@@ -270,7 +270,7 @@ module.exports.tests.slop = function(test, common){
             'slop': 3,
           }
         }}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -282,29 +282,29 @@ module.exports.tests.slop = function(test, common){
 };
 
 // @see: https://github.com/pelias/api/issues/600
-module.exports.tests.unicode = function(test, common){
-  test( 'normalization', function(t){
+module.exports.tests.unicode = (test, common) => {
+  test( 'normalization', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasPhrase' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasPhrase' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
-    var latin_large_letter_e_with_acute = String.fromCodePoint(0x00C9);
-    var latin_small_letter_e_with_acute = String.fromCodePoint(0x00E9);
-    var combining_acute_accent = String.fromCodePoint(0x0301);
-    var latin_large_letter_e = String.fromCodePoint(0x0045);
-    var latin_small_letter_e = String.fromCodePoint(0x0065);
+    const latin_large_letter_e_with_acute = String.fromCodePoint(0x00C9);
+    const latin_small_letter_e_with_acute = String.fromCodePoint(0x00E9);
+    const combining_acute_accent = String.fromCodePoint(0x0301);
+    const latin_large_letter_e = String.fromCodePoint(0x0045);
+    const latin_small_letter_e = String.fromCodePoint(0x0065);
 
     // Chambéry (both forms appear the same)
-    var composed = "Chamb" + latin_small_letter_e_with_acute + "ry";
-    var decomposed = "Chamb" + combining_acute_accent + latin_small_letter_e + "ry"
+    let composed = "Chamb" + latin_small_letter_e_with_acute + "ry";
+    let decomposed = "Chamb" + combining_acute_accent + latin_small_letter_e + "ry"
 
     assertAnalysis( 'composed', composed, ['chambery'] );
     assertAnalysis( 'decomposed', decomposed, ['chambery'] );
 
     // Één (both forms appear the same)
-    var composed = latin_large_letter_e_with_acute + latin_small_letter_e_with_acute + "n";
-    var decomposed = combining_acute_accent + latin_large_letter_e + combining_acute_accent + latin_small_letter_e + "n"
+    composed = latin_large_letter_e_with_acute + latin_small_letter_e_with_acute + "n";
+    decomposed = combining_acute_accent + latin_large_letter_e + combining_acute_accent + latin_small_letter_e + "n"
 
     assertAnalysis( 'composed', composed, ['een'] );
     assertAnalysis( 'decomposed', decomposed, ['een'] );
@@ -313,13 +313,13 @@ module.exports.tests.unicode = function(test, common){
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('peliasPhrase: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/analyzer_peliasQuery.js b/integration/analyzer_peliasQuery.js
index fc5a579d..7071d654 100644
--- a/integration/analyzer_peliasQuery.js
+++ b/integration/analyzer_peliasQuery.js
@@ -7,12 +7,12 @@ const tape = require('tape'),
 
 module.exports.tests = {};
 
-module.exports.tests.analyze = function(test, common){
-  test( 'analyze', function(t){
+module.exports.tests.analyze = (test, common) => {
+  test( 'analyze', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasQuery' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasQuery' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis('tokenizer', 'foo-bar baz/42', ['foo','bar','baz','42']);
     assertAnalysis('tokenizer', 'foo-bar  baz/42', ['foo','bar','baz','42']); // tab instead of space
@@ -26,10 +26,10 @@ module.exports.tests.analyze = function(test, common){
     assertAnalysis('digit_glued_to_word', 'john doe42', ['john', 'doe42']);
     if (config.schema.icuTokenizer) {
       assertAnalysis('thai_tonemarks', 'ก่ก้ก๊ก๋ข่ข้ข๊ข๋ค่ค้ค๊ค๋ฆ่ฆ้ฆ๊ฆ๋', ['กก', 'กก', 'ขขขขคคคคฆฆฆฆ']);
-      assertAnalysis('chinese_address', '北京市朝阳区东三环中路1号国际大厦A座1001室', ['北京市', '朝阳', '区', '东', '三', '环', '中路', '1', '号', '国际', '大厦', 'a', '座', '1001', '室']);  
+      assertAnalysis('chinese_address', '北京市朝阳区东三环中路1号国际大厦A座1001室', ['北京市', '朝阳', '区', '东', '三', '环', '中路', '1', '号', '国际', '大厦', 'a', '座', '1001', '室']);
     } else {
       assertAnalysis('thai_tonemarks', 'ก่ก้ก๊ก๋ข่ข้ข๊ข๋ค่ค้ค๊ค๋ฆ่ฆ้ฆ๊ฆ๋', ['กกกกขขขขคคคคฆฆฆฆ']);
-      assertAnalysis('chinese_address', '北京市朝阳区东三环中路1号国际大厦A座1001室', ['北京市朝阳区东三环中路1号国际大厦a座1001室']);  
+      assertAnalysis('chinese_address', '北京市朝阳区东三环中路1号国际大厦A座1001室', ['北京市朝阳区东三环中路1号国际大厦a座1001室']);
     }
 
     assertAnalysis('asciifolding', 'é', ['e']);
@@ -56,12 +56,12 @@ module.exports.tests.analyze = function(test, common){
   });
 };
 
-module.exports.tests.functional = function(test, common){
-  test( 'functional', function(t){
+module.exports.tests.functional = (test, common) => {
+  test( 'functional', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasQuery' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasQuery' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'country', 'Trinidad and Tobago', [ 'trinidad', 'and', 'tobago' ]);
     assertAnalysis( 'place', 'Toys "R" Us!', [ 'toys', 'r', 'us' ]);
@@ -98,12 +98,12 @@ module.exports.tests.functional = function(test, common){
   });
 };
 
-module.exports.tests.address = function(test, common){
-  test( 'address', function(t){
+module.exports.tests.address = (test, common) => {
+  test( 'address', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasQuery' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasQuery' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'address', '101 mapzen place', [
       '101', 'mapzen', 'place'
@@ -122,29 +122,29 @@ module.exports.tests.address = function(test, common){
 };
 
 // @see: https://github.com/pelias/api/issues/600
-module.exports.tests.unicode = function(test, common){
-  test( 'normalization', function(t){
+module.exports.tests.unicode = (test, common) => {
+  test( 'normalization', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasQuery' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasQuery' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
-    var latin_large_letter_e_with_acute = String.fromCodePoint(0x00C9);
-    var latin_small_letter_e_with_acute = String.fromCodePoint(0x00E9);
-    var combining_acute_accent = String.fromCodePoint(0x0301);
-    var latin_large_letter_e = String.fromCodePoint(0x0045);
-    var latin_small_letter_e = String.fromCodePoint(0x0065);
+    const latin_large_letter_e_with_acute = String.fromCodePoint(0x00C9);
+    const latin_small_letter_e_with_acute = String.fromCodePoint(0x00E9);
+    const combining_acute_accent = String.fromCodePoint(0x0301);
+    const latin_large_letter_e = String.fromCodePoint(0x0045);
+    const latin_small_letter_e = String.fromCodePoint(0x0065);
 
     // Chambéry (both forms appear the same)
-    var composed = "Chamb" + latin_small_letter_e_with_acute + "ry";
-    var decomposed = "Chamb" + combining_acute_accent + latin_small_letter_e + "ry"
+    let composed = "Chamb" + latin_small_letter_e_with_acute + "ry";
+    let decomposed = "Chamb" + combining_acute_accent + latin_small_letter_e + "ry"
 
     assertAnalysis( 'composed', composed, ['chambery'] );
     assertAnalysis( 'decomposed', decomposed, ['chambery'] );
 
     // Één (both forms appear the same)
-    var composed = latin_large_letter_e_with_acute + latin_small_letter_e_with_acute + "n";
-    var decomposed = combining_acute_accent + latin_large_letter_e + combining_acute_accent + latin_small_letter_e + "n"
+    composed = latin_large_letter_e_with_acute + latin_small_letter_e_with_acute + "n";
+    decomposed = combining_acute_accent + latin_large_letter_e + combining_acute_accent + latin_small_letter_e + "n"
 
     assertAnalysis( 'composed', composed, ['een'] );
     assertAnalysis( 'decomposed', decomposed, ['een'] );
@@ -153,13 +153,13 @@ module.exports.tests.unicode = function(test, common){
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('peliasQuery: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/analyzer_peliasStreet.js b/integration/analyzer_peliasStreet.js
index 7f861f9a..e7a553a7 100644
--- a/integration/analyzer_peliasStreet.js
+++ b/integration/analyzer_peliasStreet.js
@@ -4,12 +4,12 @@ const config = require('pelias-config').generate()
 
 module.exports.tests = {};
 
-module.exports.tests.analyze = function(test, common){
-  test( 'analyze', function(t){
+module.exports.tests.analyze = (test, common) => {
+  test( 'analyze', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasStreet' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasStreet' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'lowercase', 'F', ['f']);
     assertAnalysis( 'asciifolding', 'Max-Beer-Straße', ['0:max', '1:beer', '2:strasse', '2:str']);
@@ -41,12 +41,12 @@ module.exports.tests.analyze = function(test, common){
   });
 };
 
-module.exports.tests.functional = function(test, common){
-  test( 'functional', function(t){
+module.exports.tests.functional = (test, common) => {
+  test( 'functional', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasStreet' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasStreet' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'USA address', 'west 26th street', [ '0:west', '0:w', '1:26', '2:street', '2:st' ]);
     assertAnalysis( 'USA address', 'West 26th Street', [ '0:west', '0:w', '1:26', '2:street', '2:st' ]);
@@ -58,14 +58,14 @@ module.exports.tests.functional = function(test, common){
   });
 };
 
-module.exports.tests.normalize_punctuation = function(test, common){
-  test( 'normalize punctuation', function(t){
+module.exports.tests.normalize_punctuation = (test, common) => {
+  test( 'normalize punctuation', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasStreet' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasStreet' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
-    var expected = [ '0:chapala', '1:street', '1:st' ];
+    const expected = [ '0:chapala', '1:street', '1:st' ];
 
     assertAnalysis( 'single space', 'Chapala Street',    expected );
     assertAnalysis( 'double space', 'Chapala  Street',   expected );
@@ -76,12 +76,12 @@ module.exports.tests.normalize_punctuation = function(test, common){
   });
 };
 
-module.exports.tests.remove_ordinals = function(test, common){
-  test( 'remove ordinals', function(t){
+module.exports.tests.remove_ordinals = (test, common) => {
+  test( 'remove ordinals', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasStreet' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasStreet' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'ordindals', "1st", ["1"] );
     assertAnalysis( 'ordindals', "22nd", ["22"] );
@@ -150,14 +150,14 @@ module.exports.tests.remove_ordinals = function(test, common){
   });
 };
 
-module.exports.tests.tokenizer = function(test, common){
-  test( 'tokenizer', function(t){
+module.exports.tests.tokenizer = (test, common) => {
+  test( 'tokenizer', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasStreet' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasStreet' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
-    var expected = [ '0:bedell', '1:street', '1:st', '2:133', '3:avenue', '3:ave', '3:av' ];
+    const expected = [ '0:bedell', '1:street', '1:st', '2:133', '3:avenue', '3:ave', '3:av' ];
 
     // specify 2 streets with a delimeter
     assertAnalysis( 'forward slash', 'Bedell Street/133rd Avenue',   expected );
@@ -175,29 +175,29 @@ module.exports.tests.tokenizer = function(test, common){
 };
 
 // @see: https://github.com/pelias/api/issues/600
-module.exports.tests.unicode = function(test, common){
-  test( 'normalization', function(t){
+module.exports.tests.unicode = (test, common) => {
+  test( 'normalization', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasStreet' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasStreet' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
-    var latin_large_letter_e_with_acute = String.fromCodePoint(0x00C9);
-    var latin_small_letter_e_with_acute = String.fromCodePoint(0x00E9);
-    var combining_acute_accent = String.fromCodePoint(0x0301);
-    var latin_large_letter_e = String.fromCodePoint(0x0045);
-    var latin_small_letter_e = String.fromCodePoint(0x0065);
+    const latin_large_letter_e_with_acute = String.fromCodePoint(0x00C9);
+    const latin_small_letter_e_with_acute = String.fromCodePoint(0x00E9);
+    const combining_acute_accent = String.fromCodePoint(0x0301);
+    const latin_large_letter_e = String.fromCodePoint(0x0045);
+    const latin_small_letter_e = String.fromCodePoint(0x0065);
 
     // Chambéry (both forms appear the same)
-    var composed = "Chamb" + latin_small_letter_e_with_acute + "ry";
-    var decomposed = "Chamb" + combining_acute_accent + latin_small_letter_e + "ry"
+    let composed = "Chamb" + latin_small_letter_e_with_acute + "ry";
+    let decomposed = "Chamb" + combining_acute_accent + latin_small_letter_e + "ry"
 
     assertAnalysis( 'composed', composed, ['chambery'] );
     assertAnalysis( 'decomposed', decomposed, ['chambery'] );
 
     // Één (both forms appear the same)
-    var composed = latin_large_letter_e_with_acute + latin_small_letter_e_with_acute + "n";
-    var decomposed = combining_acute_accent + latin_large_letter_e + combining_acute_accent + latin_small_letter_e + "n"
+    composed = latin_large_letter_e_with_acute + latin_small_letter_e_with_acute + "n";
+    decomposed = combining_acute_accent + latin_large_letter_e + combining_acute_accent + latin_small_letter_e + "n"
 
     assertAnalysis( 'composed', composed, ['een'] );
     assertAnalysis( 'decomposed', decomposed, ['een'] );
@@ -206,12 +206,12 @@ module.exports.tests.unicode = function(test, common){
   });
 };
 
-module.exports.tests.germanic_street_suffixes = function (test, common) {
-  test('germanic_street_suffixes', function (t) {
+module.exports.tests.germanic_street_suffixes = (test, common) => {
+  test('germanic_street_suffixes', t => {
 
-    var suite = new Suite(common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind(null, suite, t, 'peliasStreet');
-    suite.action(function (done) { setTimeout(done, 500); }); // wait for es to bring some shards up
+    const suite = new Suite(common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind(null, suite, t, 'peliasStreet');
+    suite.action(done => { setTimeout(done, 500); }); // wait for es to bring some shards up
 
     // Germanic street suffixes
     assertAnalysis('straße', 'straße', ['0:strasse', '0:str']);
@@ -228,13 +228,13 @@ module.exports.tests.germanic_street_suffixes = function (test, common) {
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('peliasStreet: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/analyzer_peliasZip.js b/integration/analyzer_peliasZip.js
index 810b092f..ed5b3aae 100644
--- a/integration/analyzer_peliasZip.js
+++ b/integration/analyzer_peliasZip.js
@@ -1,17 +1,15 @@
 // validate analyzer is behaving as expected
 
-var tape = require('tape'),
-    Suite = require('../test/elastictest/Suite'),
-    punctuation = require('../punctuation');
+const tape = require('tape'), Suite = require('../test/elastictest/Suite'), punctuation = require('../punctuation');
 
 module.exports.tests = {};
 
-module.exports.tests.analyze = function(test, common){
-  test( 'analyze', function(t){
+module.exports.tests.analyze = (test, common) => {
+  test( 'analyze', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasZip' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasZip' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'lowercase', 'F', ['f']);
     assertAnalysis( 'trim', ' f ', ['f'] );
@@ -21,12 +19,12 @@ module.exports.tests.analyze = function(test, common){
   });
 };
 
-module.exports.tests.functional = function(test, common){
-  test( 'functional', function(t){
+module.exports.tests.functional = (test, common) => {
+  test( 'functional', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    var assertAnalysis = common.analyze.bind( null, suite, t, 'peliasZip' );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    const assertAnalysis = common.analyze.bind( null, suite, t, 'peliasZip' );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     assertAnalysis( 'usa zip', '10010', [ '10010' ]);
     assertAnalysis( 'usa zip', 10010, [ '10010' ]);
@@ -40,13 +38,13 @@ module.exports.tests.functional = function(test, common){
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('peliasZip: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/autocomplete_abbreviated_street_names.js b/integration/autocomplete_abbreviated_street_names.js
index fde4add4..6e1ee4a4 100644
--- a/integration/autocomplete_abbreviated_street_names.js
+++ b/integration/autocomplete_abbreviated_street_names.js
@@ -11,14 +11,14 @@ const getTotalHits = require('./_hits_total_helper');
 module.exports.tests = {};
 
 // index the name as 'Grolmanstraße' and then retrieve with partially complete token 'Grolmanstr.'
-module.exports.tests.index_expanded_form_search_contracted = function(test, common){
-  test( 'index expanded and retrieve contracted form', function(t){
+module.exports.tests.index_expanded_form_search_contracted = (test, common) => {
+  test( 'index expanded and retrieve contracted form', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index a document with a name which contains a synonym (center)
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1',
@@ -27,7 +27,7 @@ module.exports.tests.index_expanded_form_search_contracted = function(test, comm
     });
 
     // search using 'peliasQuery'
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: {
@@ -36,7 +36,7 @@ module.exports.tests.index_expanded_form_search_contracted = function(test, comm
             'query': 'Grolmanstr.'
           }
         }}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -109,13 +109,13 @@ module.exports.tests.index_expanded_form_search_contracted = function(test, comm
 //   });
 // };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('autocomplete abbreviated street names: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/autocomplete_directional_synonym_expansion.js b/integration/autocomplete_directional_synonym_expansion.js
index 4f409ae6..bf3dbeb6 100644
--- a/integration/autocomplete_directional_synonym_expansion.js
+++ b/integration/autocomplete_directional_synonym_expansion.js
@@ -11,14 +11,14 @@ const getTotalHits = require('./_hits_total_helper');
 module.exports.tests = {};
 
 // index the name as 'north' and then retrieve with partially complete token 'nor'
-module.exports.tests.index_and_retrieve_expanded_form = function(test, common){
-  test( 'index and retrieve expanded form', function(t){
+module.exports.tests.index_and_retrieve_expanded_form = (test, common) => {
+  test( 'index and retrieve expanded form', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index a document with a name which contains a synonym (center)
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1',
@@ -27,7 +27,7 @@ module.exports.tests.index_and_retrieve_expanded_form = function(test, common){
     });
 
     // search using 'peliasQuery'
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: {
@@ -36,7 +36,7 @@ module.exports.tests.index_and_retrieve_expanded_form = function(test, common){
             'query': 'nor'
           }
         }}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -44,7 +44,7 @@ module.exports.tests.index_and_retrieve_expanded_form = function(test, common){
     });
 
     // search using 'peliasQuery'
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: {
@@ -53,7 +53,7 @@ module.exports.tests.index_and_retrieve_expanded_form = function(test, common){
             'query': 'north'
           }
         }}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -65,14 +65,14 @@ module.exports.tests.index_and_retrieve_expanded_form = function(test, common){
 };
 
 // index the name as 'n' and then retrieve with 'n'
-module.exports.tests.index_and_retrieve_contracted_form = function(test, common){
-  test( 'index and retrieve contracted form', function(t){
+module.exports.tests.index_and_retrieve_contracted_form = (test, common) => {
+  test( 'index and retrieve contracted form', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index a document with a name which contains a synonym (center)
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1',
@@ -81,7 +81,7 @@ module.exports.tests.index_and_retrieve_contracted_form = function(test, common)
     });
 
     // search using 'peliasQuery'
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: {
@@ -90,7 +90,7 @@ module.exports.tests.index_and_retrieve_contracted_form = function(test, common)
             'query': 'n'
           }
         }}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -102,14 +102,14 @@ module.exports.tests.index_and_retrieve_contracted_form = function(test, common)
 };
 
 // index the name as 'n' and then retrieve with partially complete token 'nor'
-module.exports.tests.index_and_retrieve_mixed_form_1 = function(test, common){
-  test( 'index and retrieve mixed form 1', function(t){
+module.exports.tests.index_and_retrieve_mixed_form_1 = (test, common) => {
+  test( 'index and retrieve mixed form 1', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index a document with a name which contains a synonym (center)
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1',
@@ -118,7 +118,7 @@ module.exports.tests.index_and_retrieve_mixed_form_1 = function(test, common){
     });
 
     // search using 'peliasQuery'
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: {
@@ -127,7 +127,7 @@ module.exports.tests.index_and_retrieve_mixed_form_1 = function(test, common){
             'query': 'nor'
           }
         }}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -135,7 +135,7 @@ module.exports.tests.index_and_retrieve_mixed_form_1 = function(test, common){
     });
 
     // search using 'peliasQuery'
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: {
@@ -144,7 +144,7 @@ module.exports.tests.index_and_retrieve_mixed_form_1 = function(test, common){
             'query': 'north'
           }
         }}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -156,14 +156,14 @@ module.exports.tests.index_and_retrieve_mixed_form_1 = function(test, common){
 };
 
 // index the name as 'north' and then retrieve with 'n'
-module.exports.tests.index_and_retrieve_mixed_form_2 = function(test, common){
-  test( 'index and retrieve mixed form 2', function(t){
+module.exports.tests.index_and_retrieve_mixed_form_2 = (test, common) => {
+  test( 'index and retrieve mixed form 2', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index a document with a name which contains a synonym (center)
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1',
@@ -172,7 +172,7 @@ module.exports.tests.index_and_retrieve_mixed_form_2 = function(test, common){
     });
 
     // search using 'peliasQuery'
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: {
@@ -181,7 +181,7 @@ module.exports.tests.index_and_retrieve_mixed_form_2 = function(test, common){
             'query': 'n'
           }
         }}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -192,13 +192,13 @@ module.exports.tests.index_and_retrieve_mixed_form_2 = function(test, common){
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('autocomplete directional synonym expansion: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/autocomplete_street_synonym_expansion.js b/integration/autocomplete_street_synonym_expansion.js
index c2c21e6f..ccb10c47 100644
--- a/integration/autocomplete_street_synonym_expansion.js
+++ b/integration/autocomplete_street_synonym_expansion.js
@@ -12,14 +12,14 @@ const getTotalHits = require('./_hits_total_helper');
 module.exports.tests = {};
 
 // index the name as 'center' and then retrieve with partially complete token 'cent'
-module.exports.tests.index_and_retrieve_expanded_form = function(test, common){
-  test( 'index and retrieve expanded form', function(t){
+module.exports.tests.index_and_retrieve_expanded_form = (test, common) => {
+  test( 'index and retrieve expanded form', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index a document with a name which contains a synonym (center)
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1',
@@ -28,7 +28,7 @@ module.exports.tests.index_and_retrieve_expanded_form = function(test, common){
     });
 
     // search using 'peliasQuery'
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: {
@@ -37,7 +37,7 @@ module.exports.tests.index_and_retrieve_expanded_form = function(test, common){
             'query': 'cent'
           }
         }}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -45,7 +45,7 @@ module.exports.tests.index_and_retrieve_expanded_form = function(test, common){
     });
 
     // search using 'peliasQuery'
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: {
@@ -54,7 +54,7 @@ module.exports.tests.index_and_retrieve_expanded_form = function(test, common){
             'query': 'center'
           }
         }}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -66,14 +66,14 @@ module.exports.tests.index_and_retrieve_expanded_form = function(test, common){
 };
 
 // index the name as 'ctr' and then retrieve with 'ctr'
-module.exports.tests.index_and_retrieve_contracted_form = function(test, common){
-  test( 'index and retrieve contracted form', function(t){
+module.exports.tests.index_and_retrieve_contracted_form = (test, common) => {
+  test( 'index and retrieve contracted form', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index a document with a name which contains a synonym (center)
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1',
@@ -82,7 +82,7 @@ module.exports.tests.index_and_retrieve_contracted_form = function(test, common)
     });
 
     // search using 'peliasQuery'
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: {
@@ -91,7 +91,7 @@ module.exports.tests.index_and_retrieve_contracted_form = function(test, common)
             'query': 'ctr'
           }
         }}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -103,14 +103,14 @@ module.exports.tests.index_and_retrieve_contracted_form = function(test, common)
 };
 
 // index the name as 'ctr' and then retrieve with partially complete token 'cent'
-module.exports.tests.index_and_retrieve_mixed_form_1 = function(test, common){
-  test( 'index and retrieve mixed form 1', function(t){
+module.exports.tests.index_and_retrieve_mixed_form_1 = (test, common) => {
+  test( 'index and retrieve mixed form 1', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index a document with a name which contains a synonym (center)
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1',
@@ -119,7 +119,7 @@ module.exports.tests.index_and_retrieve_mixed_form_1 = function(test, common){
     });
 
     // search using 'peliasQuery'
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: {
@@ -128,7 +128,7 @@ module.exports.tests.index_and_retrieve_mixed_form_1 = function(test, common){
             'query': 'cent'
           }
         }}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -136,7 +136,7 @@ module.exports.tests.index_and_retrieve_mixed_form_1 = function(test, common){
     });
 
     // search using 'peliasQuery'
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: {
@@ -145,7 +145,7 @@ module.exports.tests.index_and_retrieve_mixed_form_1 = function(test, common){
             'query': 'center'
           }
         }}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -157,14 +157,14 @@ module.exports.tests.index_and_retrieve_mixed_form_1 = function(test, common){
 };
 
 // index the name as 'center' and then retrieve with 'ctr'
-module.exports.tests.index_and_retrieve_mixed_form_2 = function(test, common){
-  test( 'index and retrieve mixed form 2', function(t){
+module.exports.tests.index_and_retrieve_mixed_form_2 = (test, common) => {
+  test( 'index and retrieve mixed form 2', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index a document with a name which contains a synonym (center)
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1',
@@ -173,7 +173,7 @@ module.exports.tests.index_and_retrieve_mixed_form_2 = function(test, common){
     });
 
     // search using 'peliasQuery'
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { match: {
@@ -182,7 +182,7 @@ module.exports.tests.index_and_retrieve_mixed_form_2 = function(test, common){
             'query': 'ctr'
           }
         }}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( err, undefined );
         t.equal( getTotalHits(res.hits), 1, 'document found' );
         done();
@@ -193,13 +193,13 @@ module.exports.tests.index_and_retrieve_mixed_form_2 = function(test, common){
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('autocomplete street synonym expansion: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/bounding_box.js b/integration/bounding_box.js
index 21e5c864..d299bd90 100644
--- a/integration/bounding_box.js
+++ b/integration/bounding_box.js
@@ -5,14 +5,14 @@ const config = require('pelias-config').generate();
 
 module.exports.tests = {};
 
-module.exports.tests.index_and_retrieve = function(test, common){
-  test( 'index and retrieve', function(t){
+module.exports.tests.index_and_retrieve = (test, common) => {
+  test( 'index and retrieve', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index a document with a bbox
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1',
@@ -23,13 +23,13 @@ module.exports.tests.index_and_retrieve = function(test, common){
     });
 
     // retrieve document by id
-    suite.assert( function( done ) {
+    suite.assert( done => {
       suite.client.get(
         {
           index: suite.props.index,
           id: '1'
         },
-        function (err, res) {
+        (err, res) => {
           t.equal(err, undefined);
           t.deepEqual(res._source.bounding_box, '{"min_lat":-47.75,"max_lat":-33.9,"min_lon":163.82,"max_lon":179.42}');
           done();
@@ -41,13 +41,13 @@ module.exports.tests.index_and_retrieve = function(test, common){
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('bounding box: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/dynamic_templates.js b/integration/dynamic_templates.js
index 6e64a09c..352fa6c3 100644
--- a/integration/dynamic_templates.js
+++ b/integration/dynamic_templates.js
@@ -5,33 +5,33 @@ const config = require('pelias-config').generate();
 
 module.exports.tests = {};
 
-module.exports.tests.dynamic_templates_name = function(test, common){
+module.exports.tests.dynamic_templates_name = (test, common) => {
   test( 'document->name', nameAssertion( 'peliasIndexOneEdgeGram', common ) );
 };
 
-module.exports.tests.dynamic_templates_phrase = function(test, common){
+module.exports.tests.dynamic_templates_phrase = (test, common) => {
   test( 'document->phrase', phraseAssertion( 'peliasPhrase', common ) );
 };
 
-module.exports.tests.dynamic_templates_addendum = function(test, common){
+module.exports.tests.dynamic_templates_addendum = (test, common) => {
   test( 'addendum', addendumAssertion( 'wikipedia', JSON.stringify({ slug: 'Wikipedia' }), common ) );
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('dynamic_templates: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
 
 function nameAssertion( analyzer, common ){
-  return function(t){
+  return t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
+    const suite = new Suite( common.clientOpts, common.create );
 
     // index a document from a normal document layer
     suite.action( done => {
@@ -65,7 +65,7 @@ function nameAssertion( analyzer, common ){
 }
 
 function phraseAssertion( analyzer, common ){
-  return function(t){
+  return t => {
 
     const suite = new Suite( common.clientOpts, common.create );
 
@@ -101,7 +101,7 @@ function phraseAssertion( analyzer, common ){
 }
 
 function addendumAssertion( namespace, value, common ){
-  return function(t){
+  return t => {
 
     const suite = new Suite( common.clientOpts, common.create );
 
diff --git a/integration/multi_token_synonyms.js b/integration/multi_token_synonyms.js
index 74ef9eec..95ccb91a 100644
--- a/integration/multi_token_synonyms.js
+++ b/integration/multi_token_synonyms.js
@@ -7,16 +7,16 @@ module.exports.tests = {};
 
 // simple test to cover the issue noted in:
 // https://github.com/pelias/schema/issues/381#issuecomment-548305594
-module.exports.tests.functional = function (test, common) {
-  test('functional', function (t) {
+module.exports.tests.functional = (test, common) => {
+  test('functional', t => {
 
-    var suite = new Suite(common.clientOpts, common.create);
-    suite.action(function (done) { setTimeout(done, 500); }); // wait for es to bring some shards up
+    const suite = new Suite(common.clientOpts, common.create);
+    suite.action(done => { setTimeout(done, 500); }); // wait for es to bring some shards up
 
     // index a document with all admin values
     // note: this will return an error if multi-token synonyms are
     // not supported on ES6+
-    suite.action(function (done) {
+    suite.action(done => {
       suite.client.index({
         index: suite.props.index,
         id: '1', body: {
@@ -37,13 +37,13 @@ module.exports.tests.functional = function (test, common) {
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('multi token synonyms: ' + name, testFunction);
   }
 
-  for (var testCase in module.exports.tests) {
+  for (const testCase in module.exports.tests) {
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/run.js b/integration/run.js
index 4c906792..d4355843 100644
--- a/integration/run.js
+++ b/integration/run.js
@@ -14,15 +14,11 @@ const common = {
     schema: schema,
     create: { }
   },
-  summaryMap: (res) => {
-    return res.hits.hits.map(h => {
-      return {
-        _id: h._id,
-        _score: h._score,
-        name: h._source.name
-      };
-    });
-  },
+  summaryMap: res => res.hits.hits.map(h => ({
+    _id: h._id,
+    _score: h._score,
+    name: h._source.name
+  })),
   summary: (res) => {
     common.summaryMap( res )
           .forEach( console.dir );
@@ -50,7 +46,7 @@ const common = {
       }
     });
     // sort all the arrays so that order is irrelevant
-    for (var attr in positions){
+    for (const attr in positions){
       positions[attr] = positions[attr].sort();
     }
     return positions;
@@ -82,7 +78,7 @@ const common = {
 };
 
 function removeIndexTokensFromExpectedTokens(index, expected){
-  for (var pos in index) {
+  for (const pos in index) {
     if (!_.isArray(expected[pos])) { continue; }
     expected[pos] = expected[pos].filter(token => !index[pos].includes(token));
     if (_.isEmpty(expected[pos])) { delete expected[pos]; }
@@ -91,7 +87,7 @@ function removeIndexTokensFromExpectedTokens(index, expected){
   return expected;
 }
 
-var tests = [
+const tests = [
   require('./validate.js'),
   require('./dynamic_templates.js'),
   require('./analyzer_peliasIndexOneEdgeGram.js'),
@@ -112,6 +108,6 @@ var tests = [
   require('./admin_abbreviations.js')
 ];
 
-tests.map(function(t) {
+tests.map(t => {
   t.all(tape, common);
 });
diff --git a/integration/source_layer_sourceid_filtering.js b/integration/source_layer_sourceid_filtering.js
index 5b3e5cb5..3c60df32 100644
--- a/integration/source_layer_sourceid_filtering.js
+++ b/integration/source_layer_sourceid_filtering.js
@@ -6,35 +6,35 @@ const getTotalHits = require('./_hits_total_helper');
 
 module.exports.tests = {};
 
-module.exports.tests.source_filter = function(test, common){
-  test( 'source filter', function(t){
+module.exports.tests.source_filter = (test, common) => {
+  test( 'source filter', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
-    suite.action( function( done ){ setTimeout( done, 500 ); }); // wait for es to bring some shards up
+    const suite = new Suite( common.clientOpts, common.create );
+    suite.action( done => { setTimeout( done, 500 ); }); // wait for es to bring some shards up
 
     // index some docs
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '1', body: { source: 'osm', layer: 'node', source_id: 'dataset/1' }
       }, done );
     });
 
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index, 
         id: '2', body: { source: 'osm', layer: 'address', source_id: 'dataset/2' }
       }, done );
     });
 
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index, 
         id: '3', body: { source: 'geonames', layer: 'address', source_id: 'dataset/1' }
       }, done );
     });
 
-    suite.action( function( done ){
+    suite.action( done => {
       suite.client.index({
         index: suite.props.index,
         id: '4', body: { source: 'foo bar baz' }
@@ -42,7 +42,7 @@ module.exports.tests.source_filter = function(test, common){
     });
 
     // find all 'osm' sources
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: {
@@ -50,14 +50,14 @@ module.exports.tests.source_filter = function(test, common){
             source: 'osm'
           }
         }}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( getTotalHits(res.hits), 2 );
         done();
       });
     });
 
     // find all 'address' layers
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: {
@@ -65,14 +65,14 @@ module.exports.tests.source_filter = function(test, common){
             layer: 'address'
           }
         }}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( getTotalHits(res.hits), 2 );
         done();
       });
     });
 
     // find all 'shop' source_ids
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: {
@@ -80,28 +80,28 @@ module.exports.tests.source_filter = function(test, common){
             source_id: 'dataset/1'
           }
         }}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( getTotalHits(res.hits), 2 );
         done();
       });
     });
 
     // find all 'shop' source_ids from 'osm' source
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: { bool: { must: [
           { term: { source: 'osm' } },
           { term: { source_id: 'dataset/1' } }
         ]}}}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( getTotalHits(res.hits), 1 );
         done();
       });
     });
 
     // case sensitive
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: {
@@ -109,14 +109,14 @@ module.exports.tests.source_filter = function(test, common){
             source: 'OSM'
           }
         }}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( getTotalHits(res.hits), 0 );
         done();
       });
     });
 
     // keyword analysis - no partial matching
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: {
@@ -124,14 +124,14 @@ module.exports.tests.source_filter = function(test, common){
             source: 'foo'
           }
         }}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( getTotalHits(res.hits), 0 );
         done();
       });
     });
 
     // keyword analysis - allows spaces
-    suite.assert( function( done ){
+    suite.assert( done => {
       suite.client.search({
         index: suite.props.index,
         body: { query: {
@@ -139,7 +139,7 @@ module.exports.tests.source_filter = function(test, common){
             source: 'foo bar baz'
           }
         }}
-      }, function( err, res ){
+      }, (err, res) => {
         t.equal( getTotalHits(res.hits), 1 );
         done();
       });
@@ -149,13 +149,13 @@ module.exports.tests.source_filter = function(test, common){
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('field filtering: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/integration/validate.js b/integration/validate.js
index 31622e98..7432b700 100644
--- a/integration/validate.js
+++ b/integration/validate.js
@@ -5,10 +5,10 @@ const Suite = require('../test/elastictest/Suite');
 
 module.exports.tests = {};
 
-module.exports.tests.validate = function(test, common){
+module.exports.tests.validate = (test, common) => {
   test( 'schema', t => {
 
-    var suite = new Suite( common.clientOpts, common.create );
+    const suite = new Suite( common.clientOpts, common.create );
 
     suite.assert( done => {
       suite.client.info({}, ( err, res, status ) => {
@@ -21,13 +21,13 @@ module.exports.tests.validate = function(test, common){
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('validate: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/mappings/document.js b/mappings/document.js
index da22b396..e8e23c21 100644
--- a/mappings/document.js
+++ b/mappings/document.js
@@ -6,7 +6,7 @@ const multiplier = require('./partial/multiplier');
 const keyword = require('./partial/keyword');
 const keyword_with_doc_values = require('./partial/keyword_with_doc_values');
 
-var schema = {
+const schema = {
   properties: {
 
     // data partitioning
diff --git a/scripts/cli.js b/scripts/cli.js
index fb0d7b56..bb998544 100644
--- a/scripts/cli.js
+++ b/scripts/cli.js
@@ -3,7 +3,7 @@ const util = require('util');
 const colors = require('colors/safe');
 
 module.exports.header = function( text ){
-  var rule = new Array( text.length + 3 ).join("-");
+  const rule = new Array( text.length + 3 ).join("-");
   console.log( util.format("\n\033[0;33m%s\n %s \n%s\033[0m\n", rule, text, rule ) );
 }
 
diff --git a/scripts/drop_index.js b/scripts/drop_index.js
index 100ad2ec..036b8026 100644
--- a/scripts/drop_index.js
+++ b/scripts/drop_index.js
@@ -19,7 +19,7 @@ function drop() {
 
 // check all hosts to see if any is not localhost
 function warnIfNotLocal() {
-  if (config.esclient.hosts.some((env) => { return env.host !== 'localhost'; })) {
+  if (config.esclient.hosts.some(env => env.host !== 'localhost')) {
     console.log(colors.red(`WARNING: DROPPING SCHEMA NOT ON LOCALHOST: ${config.esclient.hosts[0].host}`));
   }
 }
@@ -38,5 +38,5 @@ function fail() {
 }
 
 function isForced() {
-  return process.argv.length > 2 && ['--force-yes', '-f'].indexOf(process.argv[2]) > -1;
+  return process.argv.length > 2 && ['--force-yes', '-f'].includes(process.argv[2]);
 }
\ No newline at end of file
diff --git a/scripts/info.js b/scripts/info.js
index 373dbccf..7a44379e 100644
--- a/scripts/info.js
+++ b/scripts/info.js
@@ -1,5 +1,5 @@
-var config = require('pelias-config').generate().esclient;
-var es = require('elasticsearch');
-var client = new es.Client(config);
+const config = require('pelias-config').generate().esclient;
+const es = require('elasticsearch');
+const client = new es.Client(config);
 
 client.info( {}, console.log.bind(console) );
diff --git a/scripts/list_analyzers.js b/scripts/list_analyzers.js
index f7e367c6..6adaffa9 100644
--- a/scripts/list_analyzers.js
+++ b/scripts/list_analyzers.js
@@ -7,7 +7,7 @@ const NOT_APPLICABLE_ANALYZER = 'n/a';
 const DEFAULT_NORMALIZER = '{none}';
 const NOT_APPLICABLE_NORMALIZER = 'n/a';
 
-const defaultAnalyzerFor = function(mapping){
+const defaultAnalyzerFor = mapping => {
   switch (mapping.type){
     case 'text': return DEFAULT_ANALYZER;
     case 'string': return DEFAULT_ANALYZER;
@@ -15,7 +15,7 @@ const defaultAnalyzerFor = function(mapping){
   return NOT_APPLICABLE_ANALYZER;
 }
 
-const defaultNormalizerFor = function (mapping) {
+const defaultNormalizerFor = mapping => {
   switch (mapping.type) {
     case 'keyword': return DEFAULT_NORMALIZER;
   }
@@ -23,7 +23,7 @@ const defaultNormalizerFor = function (mapping) {
 }
 
 // pretty print a single analyzer/normalizer label
-const pretty = function(analyzer){
+const pretty = analyzer => {
   if (analyzer === DEFAULT_ANALYZER) {
     return colors.blue(analyzer)
   }
@@ -37,7 +37,7 @@ const pretty = function(analyzer){
 }
 
 // pretty print a single line
-const print = function(vals) {
+const print = vals => {
   console.error(
     colors.brightBlue(vals.field.padEnd(32)),
     vals.type.padEnd(32),
@@ -48,7 +48,7 @@ const print = function(vals) {
 }
 
 // pretty print an error
-const error = function(vals) {
+const error = vals => {
   console.error(Object.values(vals).map(v => colors.red(v)).join(' | '));
 }
 
@@ -57,7 +57,7 @@ const mapping = schema.mappings;
 const dynamic = mapping.dynamic_templates.map(t => _.first(_.map(t, v => v)));
 
 // process and single mapping property (recursively)
-const property = function(prop, field){
+const property = (prop, field) => {
   // properties with subfields
   if (prop.type === 'object') {
     // recurse the object properties
diff --git a/scripts/output_mapping.js b/scripts/output_mapping.js
index 3cc6b050..9d8426a1 100644
--- a/scripts/output_mapping.js
+++ b/scripts/output_mapping.js
@@ -1,4 +1,4 @@
-var schema = require('../schema');
+const schema = require('../schema');
 
 console.log( JSON.stringify( schema.mappings, null, 2 ) );
 
diff --git a/scripts/update_settings.js b/scripts/update_settings.js
index 22d7b9c5..87429523 100644
--- a/scripts/update_settings.js
+++ b/scripts/update_settings.js
@@ -1,9 +1,9 @@
-var config = require('pelias-config').generate();
-var es = require('elasticsearch');
-var client = new es.Client(config.esclient);
-var schema = require('../schema');
+const config = require('pelias-config').generate();
+const es = require('elasticsearch');
+const client = new es.Client(config.esclient);
+const schema = require('../schema');
 
-var _index = config.schema.indexName;
+const _index = config.schema.indexName;
 
 // Error: ElasticsearchIllegalArgumentException[can't change the number of shards for an index
 if( schema.settings.hasOwnProperty('index') &&
@@ -12,11 +12,11 @@ if( schema.settings.hasOwnProperty('index') &&
   delete schema.settings.index.number_of_replicas;
 }
 
-client.indices.close( { index: _index }, function( err, res ){
+client.indices.close( { index: _index }, (err, res) => {
   console.log( '[close index]', '\t', _index, err || '\t', res );
-  client.indices.putSettings( { index: _index, body: schema.settings }, function( err, res ){
+  client.indices.putSettings( { index: _index, body: schema.settings }, (err, res) => {
     console.log( '[put settings]', '\t', _index, err || '\t', res );
-    client.indices.open( { index: _index }, function( err, res ){
+    client.indices.open( { index: _index }, (err, res) => {
       console.log( '[open index]', '\t', _index, err || '\t', res );
       process.exit( !!err );
     });
diff --git a/settings.js b/settings.js
index be3ad673..5208e4fb 100644
--- a/settings.js
+++ b/settings.js
@@ -243,9 +243,7 @@ function generate(){
       "char_filter": {
         "punctuation" : {
           "type" : "mapping",
-          "mappings" : punctuation.blacklist.map(function(c){
-            return c + '=>';
-          })
+          "mappings" : punctuation.blacklist.map(c => c + '=>')
         },
         "alphanumeric" : {
           "type" : "pattern_replace",
diff --git a/synonyms/country_codes/generate.js b/synonyms/country_codes/generate.js
index 80070d0b..a7b9f928 100644
--- a/synonyms/country_codes/generate.js
+++ b/synonyms/country_codes/generate.js
@@ -4,8 +4,8 @@ const path = require('path');
 const iso3166 = require('iso3166-1');
 const filename = path.join(__dirname, 'iso3166.txt');
 const comparer = (a, b) => {
-  var aa = a.replace(/^#/, '')
-  var bb = b.replace(/^#/, '')
+  const aa = a.replace(/^#/, '');
+  const bb = b.replace(/^#/, '');
   if (aa < bb){ return -1; }
   if (aa > bb){ return 1; }
   return 0;
@@ -15,7 +15,7 @@ const nonstandard = {
 }
 const mapper = (row) => {
   const columns = [row.alpha3, row.alpha2];
-  var prefix = '';
+  let prefix = '';
 
   // comment-out synonyms where alpha2 is a prefix of alpha3
   // if (row.alpha3.startsWith(row.alpha2)){
@@ -23,7 +23,7 @@ const mapper = (row) => {
   // }
 
   // add informal synonyms
-  var ns = _.get(nonstandard, columns[0])
+  const ns = _.get(nonstandard, columns[0]);
   if (ns){
     if (prefix === ''){
       // set as 3rd synonym
diff --git a/test/compile.js b/test/compile.js
index b1d922ac..05b9109b 100644
--- a/test/compile.js
+++ b/test/compile.js
@@ -14,8 +14,8 @@ const forEachDeep = (obj, cb) =>
 
 module.exports.tests = {};
 
-module.exports.tests.compile = function(test, common) {
-  test('valid schema file', function(t) {
+module.exports.tests.compile = (test, common) => {
+  test('valid schema file', t => {
     t.equal(typeof schema, 'object', 'schema generated');
     t.equal(Object.keys(schema).length>0, true, 'schema has body');
     t.end();
@@ -25,8 +25,8 @@ module.exports.tests.compile = function(test, common) {
 // admin indices are explicitly specified in order to specify a custom
 // dynamic_template and to avoid 'type not found' errors when deploying
 // the api codebase against an index without admin data
-module.exports.tests.indices = function(test, common) {
-  test('explicitly specify some admin indices and their analyzer', function(t) {
+module.exports.tests.indices = (test, common) => {
+  test('explicitly specify some admin indices and their analyzer', t => {
     t.equal(typeof schema.mappings, 'object', 'mappings present');
     t.equal(schema.mappings.dynamic_templates[0].nameGram.mapping.analyzer, 'peliasIndexOneEdgeGram');
     t.end();
@@ -34,10 +34,10 @@ module.exports.tests.indices = function(test, common) {
 };
 
 // some 'admin' types allow single edgeNGrams and so have a different dynamic_template
-module.exports.tests.dynamic_templates = function(test, common) {
-  test('dynamic_templates: nameGram', function(t) {
+module.exports.tests.dynamic_templates = (test, common) => {
+  test('dynamic_templates: nameGram', t => {
     t.equal(typeof schema.mappings.dynamic_templates[0].nameGram, 'object', 'nameGram template specified');
-    var template = schema.mappings.dynamic_templates[0].nameGram;
+    const template = schema.mappings.dynamic_templates[0].nameGram;
     t.equal(template.path_match, 'name.*');
     t.equal(template.match_mapping_type, 'string');
     t.deepEqual(template.mapping, {
@@ -48,9 +48,9 @@ module.exports.tests.dynamic_templates = function(test, common) {
     });
     t.end();
   });
-  test('dynamic_templates: phrase', function (t) {
+  test('dynamic_templates: phrase', t => {
     t.equal(typeof schema.mappings.dynamic_templates[1].phrase, 'object', 'phrase template specified');
-    var template = schema.mappings.dynamic_templates[1].phrase;
+    const template = schema.mappings.dynamic_templates[1].phrase;
     t.equal(template.path_match, 'phrase.*');
     t.equal(template.match_mapping_type, 'string');
     t.deepEqual(template.mapping, {
@@ -61,9 +61,9 @@ module.exports.tests.dynamic_templates = function(test, common) {
     });
     t.end();
   });
-  test('dynamic_templates: addendum', function (t) {
+  test('dynamic_templates: addendum', t => {
     t.equal(typeof schema.mappings.dynamic_templates[2].addendum, 'object', 'addendum template specified');
-    var template = schema.mappings.dynamic_templates[2].addendum;
+    const template = schema.mappings.dynamic_templates[2].addendum;
     t.equal(template.path_match, 'addendum.*');
     t.equal(template.match_mapping_type, 'string');
     t.deepEqual(template.mapping, {
@@ -76,8 +76,8 @@ module.exports.tests.dynamic_templates = function(test, common) {
 };
 
 // ensure both "analyzer" and "search_analyzer" are set for stringy fields
-module.exports.tests.analyzers = function (test, common) {
-  test('analyzers: ensure "analyzer" and "search_analyzer" are set', function (t) {
+module.exports.tests.analyzers = (test, common) => {
+  test('analyzers: ensure "analyzer" and "search_analyzer" are set', t => {
 
     const stringyTypes = ['string', 'text'];
     const stringyFields = [];
@@ -112,11 +112,11 @@ function overridePeliasConfig(value, cb) {
 
 // current schema (compiled) - requires schema to be copied and settings to
 // be regenerated from a fixture in order to pass in CI environments.
-module.exports.tests.current_schema = function(test, common) {
-  test('current schema vs. fixture', function(t) {
+module.exports.tests.current_schema = (test, common) => {
+  test('current schema vs. fixture', t => {
 
     // copy schema
-    var schemaCopy = JSON.parse( JSON.stringify( schema ) );
+    const schemaCopy = JSON.parse( JSON.stringify( schema ) );
 
     // use the pelias config fixture instead of the local config
     overridePeliasConfig(path.resolve( __dirname + '/fixtures/config.json' ), () => {
@@ -135,10 +135,10 @@ module.exports.tests.current_schema = function(test, common) {
     t.end();
   });
 
-  test('current schema vs. fixture with ICU tokenizer', function(t) {
+  test('current schema vs. fixture with ICU tokenizer', t => {
 
     // copy schema
-    var schemaCopy = JSON.parse( JSON.stringify( schema ) );
+    const schemaCopy = JSON.parse( JSON.stringify( schema ) );
 
     // use the pelias config fixture instead of the local config
     overridePeliasConfig(path.resolve( __dirname + '/fixtures/config-icu-tokenizer.json' ), () => {
@@ -158,13 +158,13 @@ module.exports.tests.current_schema = function(test, common) {
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('compile: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/test/configValidation.js b/test/configValidation.js
index f5469b6a..66cb33d9 100644
--- a/test/configValidation.js
+++ b/test/configValidation.js
@@ -4,42 +4,42 @@ const configValidation = require('../configValidation');
 
 module.exports.tests = {};
 
-module.exports.tests.interface = function(test, common) {
-  test('config without schema should throw error', function(t) {
-    var config = {
+module.exports.tests.interface = (test, common) => {
+  test('config without schema should throw error', t => {
+    const config = {
       esclient: {}
     };
 
-    t.throws(function() {
+    t.throws(() => {
       configValidation.validate(config);
     }, /"schema" is required/, 'schema should exist');
     t.end();
 
   });
 
-  test('config without schema.indexName should throw error', function(t) {
-    var config = {
+  test('config without schema.indexName should throw error', t => {
+    const config = {
       schema: {},
       esclient: {}
     };
 
-    t.throws(function() {
+    t.throws(() => {
       configValidation.validate(config);
     }, /"schema.indexName" is required/, 'schema.indexName should exist');
     t.end();
 
   });
 
-  test('config with non-string schema.indexName should throw error', function(t) {
+  test('config with non-string schema.indexName should throw error', t => {
     [null, 17, {}, [], false].forEach((value) => {
-      var config = {
+      const config = {
         schema: {
           indexName: value,
         },
         esclient: {}
       };
 
-      t.throws(function() {
+      t.throws(() => {
         configValidation.validate(config);
       }, /"schema.indexName" must be a string/, 'schema.indexName should be a string');
 
@@ -49,16 +49,16 @@ module.exports.tests.interface = function(test, common) {
 
   });
 
-  test('config with non-object esclient should throw error', function(t) {
+  test('config with non-object esclient should throw error', t => {
     [null, 17, [], 'string', true].forEach((value) => {
-      var config = {
+      const config = {
         schema: {
           indexName: 'example_index',
         },
         esclient: value
       };
 
-      t.throws(function() {
+      t.throws(() => {
         configValidation.validate(config);
       }, /"esclient" must be of type object/, 'esclient should be an object');
 
@@ -68,15 +68,15 @@ module.exports.tests.interface = function(test, common) {
 
   });
 
-  test('config with string schema.indexName and object esclient should not throw error', function(t) {
-    var config = {
+  test('config with string schema.indexName and object esclient should not throw error', t => {
+    const config = {
       schema: {
         indexName: 'example_index',
       },
       esclient: {}
     };
 
-    t.doesNotThrow(function() {
+    t.doesNotThrow(() => {
       configValidation.validate(config);
     }, 'no error should have been thrown');
 
@@ -86,13 +86,13 @@ module.exports.tests.interface = function(test, common) {
 
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('configValidation: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/test/document.js b/test/document.js
index 81aed4aa..d004a685 100644
--- a/test/document.js
+++ b/test/document.js
@@ -3,8 +3,8 @@ const schema = require('../mappings/document');
 
 module.exports.tests = {};
 
-module.exports.tests.compile = function(test, common) {
-  test('valid schema file', function(t) {
+module.exports.tests.compile = (test, common) => {
+  test('valid schema file', t => {
     t.equal(typeof schema, 'object', 'schema generated');
     t.equal(Object.keys(schema).length>0, true, 'schema has body');
     t.end();
@@ -12,28 +12,28 @@ module.exports.tests.compile = function(test, common) {
 };
 
 // properties should always be set
-module.exports.tests.properties = function(test, common) {
-  test('has properties', function(t) {
+module.exports.tests.properties = (test, common) => {
+  test('has properties', t => {
     t.equal(typeof schema.properties, 'object', 'properties specified');
     t.end();
   });
 };
 
 // should contain the correct field definitions
-module.exports.tests.fields = function(test, common) {
-  var fields = ['source', 'layer', 'name', 'phrase', 'address_parts',
+module.exports.tests.fields = (test, common) => {
+  const fields = ['source', 'layer', 'name', 'phrase', 'address_parts',
     'parent', 'center_point', 'shape', 'bounding_box', 'source_id', 'category',
     'population', 'popularity', 'addendum'];
-  test('fields specified', function(t) {
+  test('fields specified', t => {
     t.deepEqual(Object.keys(schema.properties), fields);
     t.end();
   });
 };
 
 // should contain the correct address field definitions
-module.exports.tests.address_fields = function(test, common) {
-  var fields = ['name','unit','number','street','cross_street','zip'];
-  test('address fields specified', function(t) {
+module.exports.tests.address_fields = (test, common) => {
+  const fields = ['name','unit','number','street','cross_street','zip'];
+  test('address fields specified', t => {
     t.deepEqual(Object.keys(schema.properties.address_parts.properties), fields);
     t.end();
   });
@@ -41,12 +41,12 @@ module.exports.tests.address_fields = function(test, common) {
 
 // address field analysis
 // ref: https://github.com/pelias/schema/pull/77
-module.exports.tests.address_analysis = function(test, common) {
-  var prop = schema.properties.address_parts.properties;
+module.exports.tests.address_analysis = (test, common) => {
+  const prop = schema.properties.address_parts.properties;
 
   // $name analysis is pretty basic, work can be done to improve this, although
   // at time of writing this field was not used by any API queries.
-  test('name', function(t) {
+  test('name', t => {
     t.equal(prop.name.type, 'text');
     t.equal(prop.name.analyzer, 'keyword');
     t.equal(prop.name.search_analyzer, 'keyword');
@@ -54,7 +54,7 @@ module.exports.tests.address_analysis = function(test, common) {
   });
 
   // $unit analysis
-  test('unit', function(t) {
+  test('unit', t => {
     t.equal(prop.unit.type, 'text', 'unit has full text type');
     t.equal(prop.unit.analyzer, 'peliasUnit', 'unit analyzer is peliasUnit');
     t.equal(prop.unit.search_analyzer, 'peliasUnit', 'unit search_analyzer is peliasUnit');
@@ -62,7 +62,7 @@ module.exports.tests.address_analysis = function(test, common) {
   });
 
   // $number analysis is discussed in: https://github.com/pelias/schema/pull/77
-  test('number', function(t) {
+  test('number', t => {
     t.equal(prop.number.type, 'text');
     t.equal(prop.number.analyzer, 'peliasHousenumber');
     t.equal(prop.number.search_analyzer, 'peliasHousenumber');
@@ -71,7 +71,7 @@ module.exports.tests.address_analysis = function(test, common) {
 
   // $street analysis is discussed in: https://github.com/pelias/schema/pull/77
   // and https://github.com/pelias/api/pull/1444
-  test('street', function(t) {
+  test('street', t => {
     t.equal(prop.street.type, 'text');
     t.equal(prop.street.analyzer, 'peliasStreet');
     t.equal(prop.street.search_analyzer, 'peliasQuery');
@@ -79,7 +79,7 @@ module.exports.tests.address_analysis = function(test, common) {
   });
 
   // $cross_street analysis
-  test('cross_street', function (t) {
+  test('cross_street', t => {
     t.equal(prop.cross_street.type, 'text');
     t.equal(prop.cross_street.analyzer, 'peliasStreet');
     t.equal(prop.cross_street.search_analyzer, 'peliasQuery');
@@ -89,7 +89,7 @@ module.exports.tests.address_analysis = function(test, common) {
   // $zip analysis is discussed in: https://github.com/pelias/schema/pull/77
   // note: this is a poor name, it would be better to rename this field to a more
   // generic term such as $postalcode as it is not specific to the USA.
-  test('zip', function(t) {
+  test('zip', t => {
     t.equal(prop.zip.type, 'text');
     t.equal(prop.zip.analyzer, 'peliasZip');
     t.equal(prop.zip.search_analyzer, 'peliasZip');
@@ -98,8 +98,8 @@ module.exports.tests.address_analysis = function(test, common) {
 };
 
 // should contain the correct parent field definitions
-module.exports.tests.parent_fields = function(test, common) {
-  var fields = [
+module.exports.tests.parent_fields = (test, common) => {
+  const fields = [
     'continent',      'continent_a',      'continent_id',     'continent.fields.ngram',
     'ocean',          'ocean_a',          'ocean_id',         'ocean.fields.ngram',
     'empire',         'empire_a',         'empire_id',        'empire.fields.ngram',
@@ -116,7 +116,7 @@ module.exports.tests.parent_fields = function(test, common) {
     'neighbourhood',  'neighbourhood_a',  'neighbourhood_id', 'neighbourhood.fields.ngram',
     'postalcode',     'postalcode_a',     'postalcode_id',    'postalcode.fields.ngram'
   ];
-  test('parent fields specified', function(t) {
+  test('parent fields specified', t => {
     fields.forEach( expected => {
       t.true( _.has( schema.properties.parent.properties, expected ), expected );
     });
@@ -126,7 +126,7 @@ module.exports.tests.parent_fields = function(test, common) {
 
 // parent field analysis
 // ref: https://github.com/pelias/schema/pull/95
-module.exports.tests.parent_analysis = function(test, common) {
+module.exports.tests.parent_analysis = (test, common) => {
   const prop = schema.properties.parent.properties;
   const fields = [
     'continent', 'ocean', 'empire', 'country', 'dependency', 'marinearea',
@@ -134,15 +134,15 @@ module.exports.tests.parent_analysis = function(test, common) {
     'localadmin', 'neighbourhood'
   ];
 
-  fields.forEach( function( field ){
-    test(field, function(t) {
+  fields.forEach( field => {
+    test(field, t => {
 
       // this is how the *default* analysis is currently set up across admin fields
       // note: we would like to move away from this to individual analyzers per-admin field.
-      var expectedFullTextIndexAnalyzer = 'peliasAdmin';
-      var expectedFullTextSearchAnalyzer = 'peliasAdmin';
-      var expectedNgramIndexAnalyzer = 'peliasIndexOneEdgeGram';
-      var expectedNgramSearchAnalyzer = 'peliasAdmin';
+      let expectedFullTextIndexAnalyzer = 'peliasAdmin';
+      let expectedFullTextSearchAnalyzer = 'peliasAdmin';
+      let expectedNgramIndexAnalyzer = 'peliasIndexOneEdgeGram';
+      let expectedNgramSearchAnalyzer = 'peliasAdmin';
 
       // id field
       t.equal(prop[field+'_id'].type, 'keyword', `${field}_id type is keyword`);
@@ -185,7 +185,7 @@ module.exports.tests.parent_analysis = function(test, common) {
     });
   });
 
-  test('postalcode', function(t) {
+  test('postalcode', t => {
     t.equal(prop['postalcode'].type, 'text', 'postalcode is full text field');
     t.equal(prop['postalcode'].analyzer, 'peliasZip', 'postalcode analyzer is peliasZip');
     t.equal(prop['postalcode'].search_analyzer, 'peliasZip', 'postalcode analyzer is peliasZip');
@@ -199,10 +199,10 @@ module.exports.tests.parent_analysis = function(test, common) {
   });
 };
 
-module.exports.tests.dynamic_templates = function(test, common) {
-  test('dynamic_templates: nameGram', function(t) {
+module.exports.tests.dynamic_templates = (test, common) => {
+  test('dynamic_templates: nameGram', t => {
     t.equal(typeof schema.dynamic_templates[0].nameGram, 'object', 'nameGram template specified');
-    var template = schema.dynamic_templates[0].nameGram;
+    const template = schema.dynamic_templates[0].nameGram;
     t.equal(template.path_match, 'name.*');
     t.equal(template.match_mapping_type, 'string');
     t.equal(template.mapping.type, 'text', 'set to full text type');
@@ -211,9 +211,9 @@ module.exports.tests.dynamic_templates = function(test, common) {
     t.equal(template.mapping.search_analyzer, 'peliasQuery', 'search_analyzer set');
     t.end();
   });
-  test('dynamic_templates: phrase', function(t) {
+  test('dynamic_templates: phrase', t => {
     t.equal(typeof schema.dynamic_templates[1].phrase, 'object', 'phrase template specified');
-    var template = schema.dynamic_templates[1].phrase;
+    const template = schema.dynamic_templates[1].phrase;
     t.equal(template.path_match, 'phrase.*');
     t.equal(template.match_mapping_type, 'string');
     t.equal(template.mapping.type, 'text', 'set to full text type');
@@ -225,8 +225,8 @@ module.exports.tests.dynamic_templates = function(test, common) {
 };
 
 // _all should be disabled
-module.exports.tests.all_disabled = function(test, common) {
-  test('_all disabled', function(t) {
+module.exports.tests.all_disabled = (test, common) => {
+  test('_all disabled', t => {
     t.false(schema._all, '_all undefined');
     t.end();
   });
@@ -235,16 +235,16 @@ module.exports.tests.all_disabled = function(test, common) {
 // dynamic should be true in order for dynamic_templates to function properly
 // @see: http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/mapping-dynamic-mapping.html
 // strict ensures extra fields cannot be added: https://www.elastic.co/guide/en/elasticsearch/guide/current/dynamic-mapping.html
-module.exports.tests.dynamic_disabled = function(test, common) {
-  test('dynamic strict', function(t) {
+module.exports.tests.dynamic_disabled = (test, common) => {
+  test('dynamic strict', t => {
     t.equal(schema.dynamic, 'strict', 'dynamic true');
     t.end();
   });
 };
 
 // shape field should be exluded from _source because it's massive
-module.exports.tests._source = function(test, common) {
-  test('_source', function(t) {
+module.exports.tests._source = (test, common) => {
+  test('_source', t => {
     t.ok(Array.isArray(schema._source.excludes), 'exclusions specified');
     t.equal(schema._source.excludes[0], 'shape', 'exclude shape');
     t.equal(schema._source.excludes[1], 'phrase', 'exclude phrase');
@@ -252,13 +252,13 @@ module.exports.tests._source = function(test, common) {
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('document: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/test/partial-admin.js b/test/partial-admin.js
index 09f52d53..bee5ae6d 100644
--- a/test/partial-admin.js
+++ b/test/partial-admin.js
@@ -1,9 +1,9 @@
-var schema = require('../mappings/partial/admin');
+const schema = require('../mappings/partial/admin');
 
 module.exports.tests = {};
 
-module.exports.tests.compile = function(test, common) {
-  test('valid schema file', function(t) {
+module.exports.tests.compile = (test, common) => {
+  test('valid schema file', t => {
     t.equal(typeof schema, 'object', 'schema generated');
     t.equal(Object.keys(schema).length>0, true, 'schema has body');
     t.end();
@@ -11,23 +11,23 @@ module.exports.tests.compile = function(test, common) {
 };
 
 // this should never need to change
-module.exports.tests.type = function(test, common) {
-  test('correct type', function(t) {
+module.exports.tests.type = (test, common) => {
+  test('correct type', t => {
     t.equal(schema.type, 'text', 'set to text field for full text search');
     t.end();
   });
 };
 
-module.exports.tests.store = function(test, common) {
-  test('store unset (will not be stored)', function(t) {
+module.exports.tests.store = (test, common) => {
+  test('store unset (will not be stored)', t => {
     t.equal(schema.store, undefined, 'unset');
     t.end();
   });
 };
 
 // this should be enabled to allow 'exists' filters to work
-module.exports.tests.index = function(test, common) {
-  test('index enabled', function(t) {
+module.exports.tests.index = (test, common) => {
+  test('index enabled', t => {
     t.notEqual(schema.index, 'no', 'should not be disabled');
     t.end();
   });
@@ -35,20 +35,20 @@ module.exports.tests.index = function(test, common) {
 
 // pelias analysis does not ensure that we get ['Great Britain'] instead of ['Great','Britain']
 // TODO this needs to be addressed
-module.exports.tests.analysis = function(test, common) {
-  test('index analysis', function(t) {
+module.exports.tests.analysis = (test, common) => {
+  test('index analysis', t => {
     t.equal(schema.analyzer, 'peliasAdmin', 'should be peliasAdmin');
     t.end();
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('admin: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/test/partial-centroid.js b/test/partial-centroid.js
index 0b745269..8c3d8d7f 100644
--- a/test/partial-centroid.js
+++ b/test/partial-centroid.js
@@ -1,10 +1,10 @@
 
-var schema = require('../mappings/partial/centroid');
+const schema = require('../mappings/partial/centroid');
 
 module.exports.tests = {};
 
-module.exports.tests.compile = function(test, common) {
-  test('valid schema file', function(t) {
+module.exports.tests.compile = (test, common) => {
+  test('valid schema file', t => {
     t.equal(typeof schema, 'object', 'schema generated');
     t.equal(Object.keys(schema).length>0, true, 'schema has body');
     t.end();
@@ -12,20 +12,20 @@ module.exports.tests.compile = function(test, common) {
 };
 
 // this should never need to change
-module.exports.tests.type = function(test, common) {
-  test('correct type', function(t) {
+module.exports.tests.type = (test, common) => {
+  test('correct type', t => {
     t.equal(schema.type, 'geo_point', 'correct value');
     t.end();
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('centroid: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/test/partial-hash.js b/test/partial-hash.js
index bb69261c..1338db8b 100644
--- a/test/partial-hash.js
+++ b/test/partial-hash.js
@@ -1,9 +1,9 @@
-var schema = require('../mappings/partial/hash');
+const schema = require('../mappings/partial/hash');
 
 module.exports.tests = {};
 
-module.exports.tests.compile = function(test, common) {
-  test('valid schema file', function(t) {
+module.exports.tests.compile = (test, common) => {
+  test('valid schema file', t => {
     t.equal(typeof schema, 'object', 'schema generated');
     t.equal(Object.keys(schema).length>0, true, 'schema has body');
     t.end();
@@ -11,8 +11,8 @@ module.exports.tests.compile = function(test, common) {
 };
 
 // this should never need to change
-module.exports.tests.type = function(test, common) {
-  test('correct type', function(t) {
+module.exports.tests.type = (test, common) => {
+  test('correct type', t => {
     t.equal(schema.type, 'object', 'correct value');
     t.end();
   });
@@ -20,20 +20,20 @@ module.exports.tests.type = function(test, common) {
 
 // if dynamic=false you won't be able to
 // query the properties of the object!
-module.exports.tests.dynamic = function(test, common) {
-  test('dynamic true', function(t) {
+module.exports.tests.dynamic = (test, common) => {
+  test('dynamic true', t => {
     t.equal(schema.dynamic, true, 'correct value');
     t.end();
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('hash: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/test/partial-keyword.js b/test/partial-keyword.js
index 03878009..62587cd3 100644
--- a/test/partial-keyword.js
+++ b/test/partial-keyword.js
@@ -1,9 +1,9 @@
-var schema = require('../mappings/partial/keyword');
+const schema = require('../mappings/partial/keyword');
 
 module.exports.tests = {};
 
-module.exports.tests.compile = function(test, common) {
-  test('valid schema file', function(t) {
+module.exports.tests.compile = (test, common) => {
+  test('valid schema file', t => {
     t.equal(typeof schema, 'object', 'schema generated');
     t.equal(Object.keys(schema).length>0, true, 'schema has body');
     t.end();
@@ -11,35 +11,35 @@ module.exports.tests.compile = function(test, common) {
 };
 
 // this should never need to change
-module.exports.tests.type = function(test, common) {
-  test('correct type', function(t) {
+module.exports.tests.type = (test, common) => {
+  test('correct type', t => {
     t.equal(schema.type, 'keyword', 'correct value');
     t.end();
   });
 };
 
-module.exports.tests.store = function(test, common) {
-  test('store unset (will not be stored)', function(t) {
+module.exports.tests.store = (test, common) => {
+  test('store unset (will not be stored)', t => {
     t.equal(schema.store, undefined, 'unset');
     t.end();
   });
 };
 
 // do not perform analysis on categories
-module.exports.tests.analysis = function(test, common) {
-  test('index analysis disabled', function(t) {
+module.exports.tests.analysis = (test, common) => {
+  test('index analysis disabled', t => {
     t.equal(schema.index, undefined, 'should be set to default');
     t.end();
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('keyword: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/test/run.js b/test/run.js
index 185d144f..37b5b3b0 100644
--- a/test/run.js
+++ b/test/run.js
@@ -1,14 +1,13 @@
-var tape = require('tape'),
-    diff = require('difflet')({ indent : 2, comment : true });
+const tape = require('tape'), diff = require('difflet')({ indent : 2, comment : true });
 
-var common = {
+const common = {
   // a visual deep diff rendered using console.error()
   diff: function( actual, expected ){
     console.error( diff.compare( actual, expected ) );
   }
 };
 
-var tests = [
+const tests = [
   require('./compile.js'),
   require('./document.js'),
   require('./partial-centroid.js'),
@@ -20,6 +19,6 @@ var tests = [
   require('./synonyms/parser.js'),
 ];
 
-tests.map(function(t) {
+tests.map(t => {
   t.all(tape, common);
 });
diff --git a/test/settings.js b/test/settings.js
index 37789dfd..dc95ac19 100644
--- a/test/settings.js
+++ b/test/settings.js
@@ -5,16 +5,16 @@ const path = require('path'),
 
 module.exports.tests = {};
 
-module.exports.tests.interface = function(test, common) {
-  test('valid interface', function(t) {
+module.exports.tests.interface = (test, common) => {
+  test('valid interface', t => {
     t.equal(typeof settings, 'function', 'settings is a function');
     t.end();
   });
 };
 
-module.exports.tests.configValidation = function(test, common) {
-  test('configValidation throwing error should rethrow', function(t) {
-    t.throws(function() {
+module.exports.tests.configValidation = (test, common) => {
+  test('configValidation throwing error should rethrow', t => {
+    t.throws(() => {
       const proxyquire = require('proxyquire').noCallThru();
       proxyquire('../settings', {
         './configValidation': {
@@ -31,9 +31,9 @@ module.exports.tests.configValidation = function(test, common) {
   });
 };
 
-module.exports.tests.compile = function(test, common) {
-  test('valid settings file', function(t) {
-    var s = settings();
+module.exports.tests.compile = (test, common) => {
+  test('valid settings file', t => {
+    const s = settings();
     t.equal(typeof s, 'object', 'settings generated');
     t.equal(Object.keys(s).length>0, true, 'settings has body');
     t.end();
@@ -41,9 +41,9 @@ module.exports.tests.compile = function(test, common) {
 };
 
 // analysis should always be set
-module.exports.tests.analysis = function(test, common) {
-  test('has analysis settings', function(t) {
-    var s = settings();
+module.exports.tests.analysis = (test, common) => {
+  test('has analysis settings', t => {
+    const s = settings();
     t.equal(typeof s.analysis, 'object', 'analysis specified');
     t.end();
   });
@@ -65,19 +65,19 @@ function mayBeAmpersandReplacer() {
 
 // -- analyzers --
 
-module.exports.tests.peliasAdminAnalyzer = function(test, common) {
-  test('has pelias admin analyzer', function(t) {
-    var s = settings();
+module.exports.tests.peliasAdminAnalyzer = (test, common) => {
+  test('has pelias admin analyzer', t => {
+    const s = settings();
     t.equal(typeof s.analysis.analyzer.peliasAdmin, 'object', 'there is a pelias admin analyzer');
-    var analyzer = s.analysis.analyzer.peliasAdmin;
+    const analyzer = s.analysis.analyzer.peliasAdmin;
     t.equal(analyzer.type, 'custom', 'custom analyzer');
     t.equal(typeof analyzer.tokenizer, 'string', 'tokenizer specified');
     t.deepEqual(analyzer.char_filter, [...mayBeAmpersandMapper(), 'punctuation', 'nfkc_normalizer'], 'character filters specified');
     t.true(Array.isArray(analyzer.filter), 'filters specified');
     t.end();
   });
-  test('peliasAdmin token filters', function (t) {
-    var analyzer = settings().analysis.analyzer.peliasAdmin;
+  test('peliasAdmin token filters', t => {
+    const analyzer = settings().analysis.analyzer.peliasAdmin;
     t.deepEqual(analyzer.filter, [...mayBeAmpersandReplacer(),
       "lowercase",
       "trim",
@@ -93,19 +93,19 @@ module.exports.tests.peliasAdminAnalyzer = function(test, common) {
   });
 };
 
-module.exports.tests.peliasIndexOneEdgeGramAnalyzer = function(test, common) {
-  test('has peliasIndexOneEdgeGram analyzer', function(t) {
-    var s = settings();
+module.exports.tests.peliasIndexOneEdgeGramAnalyzer = (test, common) => {
+  test('has peliasIndexOneEdgeGram analyzer', t => {
+    const s = settings();
     t.equal(typeof s.analysis.analyzer.peliasIndexOneEdgeGram, 'object', 'there is a peliasIndexOneEdgeGram analyzer');
-    var analyzer = s.analysis.analyzer.peliasIndexOneEdgeGram;
+    const analyzer = s.analysis.analyzer.peliasIndexOneEdgeGram;
     t.equal(analyzer.type, 'custom', 'custom analyzer');
     t.equal(typeof analyzer.tokenizer, 'string', 'tokenizer specified');
     t.deepEqual(analyzer.char_filter, [...mayBeAmpersandMapper(), "punctuation","nfkc_normalizer"], 'character filters specified');
     t.true(Array.isArray(analyzer.filter), 'filters specified');
     t.end();
   });
-  test('peliasIndexOneEdgeGram token filters', function(t) {
-    var analyzer = settings().analysis.analyzer.peliasIndexOneEdgeGram;
+  test('peliasIndexOneEdgeGram token filters', t => {
+    const analyzer = settings().analysis.analyzer.peliasIndexOneEdgeGram;
     t.deepEqual( analyzer.filter, [
       ...mayBeAmpersandReplacer(),
       "lowercase",
@@ -125,19 +125,19 @@ module.exports.tests.peliasIndexOneEdgeGramAnalyzer = function(test, common) {
   });
 };
 
-module.exports.tests.peliasQueryAnalyzer = function (test, common) {
-  test('has peliasQuery analyzer', function (t) {
-    var s = settings();
+module.exports.tests.peliasQueryAnalyzer = (test, common) => {
+  test('has peliasQuery analyzer', t => {
+    const s = settings();
     t.equal(typeof s.analysis.analyzer.peliasQuery, 'object', 'there is a peliasQuery analyzer');
-    var analyzer = s.analysis.analyzer.peliasQuery;
+    const analyzer = s.analysis.analyzer.peliasQuery;
     t.equal(analyzer.type, 'custom', 'custom analyzer');
     t.equal(typeof analyzer.tokenizer, 'string', 'tokenizer specified');
     t.deepEqual(analyzer.char_filter, [...mayBeAmpersandMapper(), 'punctuation', 'nfkc_normalizer'], 'character filters specified');
     t.true(Array.isArray(analyzer.filter), 'filters specified');
     t.end();
   });
-  test('peliasQuery token filters', function (t) {
-    var analyzer = settings().analysis.analyzer.peliasQuery;
+  test('peliasQuery token filters', t => {
+    const analyzer = settings().analysis.analyzer.peliasQuery;
     t.deepEqual(analyzer.filter, [
       ...mayBeAmpersandReplacer(),
       'lowercase',
@@ -151,19 +151,19 @@ module.exports.tests.peliasQueryAnalyzer = function (test, common) {
   });
 };
 
-module.exports.tests.peliasPhraseAnalyzer = function(test, common) {
-  test('has peliasPhrase analyzer', function(t) {
-    var s = settings();
+module.exports.tests.peliasPhraseAnalyzer = (test, common) => {
+  test('has peliasPhrase analyzer', t => {
+    const s = settings();
     t.equal(typeof s.analysis.analyzer.peliasPhrase, 'object', 'there is a peliasPhrase analyzer');
-    var analyzer = s.analysis.analyzer.peliasPhrase;
+    const analyzer = s.analysis.analyzer.peliasPhrase;
     t.equal(analyzer.type, 'custom', 'custom analyzer');
     t.equal(typeof analyzer.tokenizer, 'string', 'tokenizer specified');
     t.deepEqual(analyzer.char_filter, [...mayBeAmpersandMapper(), "punctuation", "nfkc_normalizer"], 'character filters specified');
     t.true(Array.isArray(analyzer.filter), 'filters specified');
     t.end();
   });
-  test('peliasPhrase token filters', function(t) {
-    var analyzer = settings().analysis.analyzer.peliasPhrase;
+  test('peliasPhrase token filters', t => {
+    const analyzer = settings().analysis.analyzer.peliasPhrase;
     t.deepEqual( analyzer.filter, [
       ...mayBeAmpersandReplacer(),
       "lowercase",
@@ -183,19 +183,19 @@ module.exports.tests.peliasPhraseAnalyzer = function(test, common) {
   });
 };
 
-module.exports.tests.peliasZipAnalyzer = function(test, common) {
-  test('has peliasZip analyzer', function(t) {
-    var s = settings();
+module.exports.tests.peliasZipAnalyzer = (test, common) => {
+  test('has peliasZip analyzer', t => {
+    const s = settings();
     t.equal(typeof s.analysis.analyzer.peliasZip, 'object', 'there is a peliasZip analyzer');
-    var analyzer = s.analysis.analyzer.peliasZip;
+    const analyzer = s.analysis.analyzer.peliasZip;
     t.equal(analyzer.type, 'custom', 'custom analyzer');
     t.equal(typeof analyzer.tokenizer, 'string', 'tokenizer specified');
     t.deepEqual(analyzer.char_filter, ['alphanumeric', 'nfkc_normalizer'], 'alphanumeric filter specified');
     t.true(Array.isArray(analyzer.filter), 'filters specified');
     t.end();
   });
-  test('peliasZip token filters', function(t) {
-    var analyzer = settings().analysis.analyzer.peliasZip;
+  test('peliasZip token filters', t => {
+    const analyzer = settings().analysis.analyzer.peliasZip;
     t.deepEqual( analyzer.filter, [
       "lowercase",
       "trim",
@@ -207,19 +207,19 @@ module.exports.tests.peliasZipAnalyzer = function(test, common) {
   });
 };
 
-module.exports.tests.peliasUnitAnalyzer = function(test, common) {
-  test('has peliasUnit analyzer', function(t) {
-    var s = settings();
+module.exports.tests.peliasUnitAnalyzer = (test, common) => {
+  test('has peliasUnit analyzer', t => {
+    const s = settings();
     t.equal(typeof s.analysis.analyzer.peliasUnit, 'object', 'there is a peliasUnit analyzer');
-    var analyzer = s.analysis.analyzer.peliasUnit;
+    const analyzer = s.analysis.analyzer.peliasUnit;
     t.equal(analyzer.type, 'custom', 'custom analyzer');
     t.equal(typeof analyzer.tokenizer, 'string', 'tokenizer specified');
     t.deepEqual(analyzer.char_filter, ['alphanumeric', 'nfkc_normalizer'], 'alphanumeric filter specified');
     t.true(Array.isArray(analyzer.filter), 'filters specified');
     t.end();
   });
-  test('peliasUnit token filters', function(t) {
-    var analyzer = settings().analysis.analyzer.peliasUnit;
+  test('peliasUnit token filters', t => {
+    const analyzer = settings().analysis.analyzer.peliasUnit;
     t.deepEqual( analyzer.filter, [
       "lowercase",
       "trim",
@@ -231,11 +231,11 @@ module.exports.tests.peliasUnitAnalyzer = function(test, common) {
   });
 };
 
-module.exports.tests.peliasHousenumberAnalyzer = function(test, common) {
-  test('has peliasHousenumber analyzer', function(t) {
-    var s = settings();
+module.exports.tests.peliasHousenumberAnalyzer = (test, common) => {
+  test('has peliasHousenumber analyzer', t => {
+    const s = settings();
     t.equal(typeof s.analysis.analyzer.peliasHousenumber, 'object', 'there is a peliasHousenumber analyzer');
-    var analyzer = s.analysis.analyzer.peliasHousenumber;
+    const analyzer = s.analysis.analyzer.peliasHousenumber;
     t.equal(analyzer.type, 'custom', 'custom analyzer');
     t.equal(typeof analyzer.tokenizer, 'string', 'tokenizer specified');
     t.deepEqual(analyzer.char_filter, ["numeric"], 'numeric filter specified');
@@ -244,19 +244,19 @@ module.exports.tests.peliasHousenumberAnalyzer = function(test, common) {
   });
 };
 
-module.exports.tests.peliasStreetAnalyzer = function(test, common) {
-  test('has peliasStreet analyzer', function(t) {
-    var s = settings();
+module.exports.tests.peliasStreetAnalyzer = (test, common) => {
+  test('has peliasStreet analyzer', t => {
+    const s = settings();
     t.equal(typeof s.analysis.analyzer.peliasStreet, 'object', 'there is a peliasStreet analyzer');
-    var analyzer = s.analysis.analyzer.peliasStreet;
+    const analyzer = s.analysis.analyzer.peliasStreet;
     t.equal(analyzer.type, 'custom', 'custom analyzer');
     t.equal(typeof analyzer.tokenizer, 'string', 'tokenizer specified');
     t.deepEqual(analyzer.char_filter, [...mayBeAmpersandMapper(), 'punctuation', 'nfkc_normalizer'], 'character filters specified');
     t.true(Array.isArray(analyzer.filter), 'filters specified');
     t.end();
   });
-  test('peliasStreet token filters', function(t) {
-    var analyzer = settings().analysis.analyzer.peliasStreet;
+  test('peliasStreet token filters', t => {
+    const analyzer = settings().analysis.analyzer.peliasStreet;
     t.deepEqual( analyzer.filter, [...mayBeAmpersandReplacer(),
       "lowercase",
       "trim",
@@ -274,19 +274,19 @@ module.exports.tests.peliasStreetAnalyzer = function(test, common) {
   });
 };
 
-module.exports.tests.peliasIndexCountryAbbreviation = function (test, common) {
-  test('has peliasIndexCountryAbbreviation analyzer', function (t) {
-    var s = settings();
+module.exports.tests.peliasIndexCountryAbbreviation = (test, common) => {
+  test('has peliasIndexCountryAbbreviation analyzer', t => {
+    const s = settings();
     t.equal(typeof s.analysis.analyzer.peliasIndexCountryAbbreviation, 'object', 'there is a peliasIndexCountryAbbreviation analyzer');
-    var analyzer = s.analysis.analyzer.peliasIndexCountryAbbreviation;
+    const analyzer = s.analysis.analyzer.peliasIndexCountryAbbreviation;
     t.equal(analyzer.type, 'custom', 'custom analyzer');
     t.equal(typeof analyzer.tokenizer, 'string', 'tokenizer specified');
     t.deepEqual(analyzer.char_filter, [...mayBeAmpersandMapper(), 'punctuation', 'nfkc_normalizer'], 'character filters specified');
     t.true(Array.isArray(analyzer.filter), 'filters specified');
     t.end();
   });
-  test('peliasIndexCountryAbbreviation token filters', function (t) {
-    var analyzer = settings().analysis.analyzer.peliasIndexCountryAbbreviation;
+  test('peliasIndexCountryAbbreviation token filters', t => {
+    const analyzer = settings().analysis.analyzer.peliasIndexCountryAbbreviation;
     t.deepEqual(analyzer.filter, [...mayBeAmpersandReplacer(),
       "lowercase",
       "trim",
@@ -300,19 +300,19 @@ module.exports.tests.peliasIndexCountryAbbreviation = function (test, common) {
   });
 };
 
-module.exports.tests.peliasIndexCountryAbbreviationOneEdgeGramAnalyzer = function (test, common) {
-  test('has peliasIndexCountryAbbreviationOneEdgeGram analyzer', function (t) {
-    var s = settings();
+module.exports.tests.peliasIndexCountryAbbreviationOneEdgeGramAnalyzer = (test, common) => {
+  test('has peliasIndexCountryAbbreviationOneEdgeGram analyzer', t => {
+    const s = settings();
     t.equal(typeof s.analysis.analyzer.peliasIndexCountryAbbreviationOneEdgeGram, 'object', 'there is a peliasIndexCountryAbbreviationOneEdgeGram analyzer');
-    var analyzer = s.analysis.analyzer.peliasIndexCountryAbbreviationOneEdgeGram;
+    const analyzer = s.analysis.analyzer.peliasIndexCountryAbbreviationOneEdgeGram;
     t.equal(analyzer.type, 'custom', 'custom analyzer');
     t.equal(typeof analyzer.tokenizer, 'string', 'tokenizer specified');
     t.deepEqual(analyzer.char_filter, [...mayBeAmpersandMapper(), "punctuation", "nfkc_normalizer"], 'character filters specified');
     t.true(Array.isArray(analyzer.filter), 'filters specified');
     t.end();
   });
-  test('peliasIndexCountryAbbreviationOneEdgeGram token filters', function (t) {
-    var analyzer = settings().analysis.analyzer.peliasIndexCountryAbbreviationOneEdgeGram;
+  test('peliasIndexCountryAbbreviationOneEdgeGram token filters', t => {
+    const analyzer = settings().analysis.analyzer.peliasIndexCountryAbbreviationOneEdgeGram;
     t.deepEqual(analyzer.filter, [
       ...mayBeAmpersandReplacer(),
       "lowercase",
@@ -332,11 +332,11 @@ module.exports.tests.peliasIndexCountryAbbreviationOneEdgeGramAnalyzer = functio
 
 // this multiplexer filter provides all the synonyms used by the peliasAdmin analyzer
 // note: the multiplexer ensures than we do not virally generate synonyms of synonyms.
-module.exports.tests.adminSynonymsMultiplexerFilter = function (test, common) {
-  test('has admin_synonyms_multiplexer filter', function (t) {
-    var s = settings();
+module.exports.tests.adminSynonymsMultiplexerFilter = (test, common) => {
+  test('has admin_synonyms_multiplexer filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.filter.admin_synonyms_multiplexer, 'object', 'there is a admin_synonyms_multiplexer filter');
-    var filter = s.analysis.filter.admin_synonyms_multiplexer;
+    const filter = s.analysis.filter.admin_synonyms_multiplexer;
     t.equal(filter.type, 'multiplexer');
     t.deepEqual(filter.filters, [
       'synonyms/custom_admin',
@@ -348,11 +348,11 @@ module.exports.tests.adminSynonymsMultiplexerFilter = function (test, common) {
 };
 
 // this multiplexer filter provides all the synonyms for country codes.
-module.exports.tests.countryAbbreviationSynonymsMultiplexerFilter = function (test, common) {
-  test('has country_abbreviation_synonyms_multiplexer filter', function (t) {
-    var s = settings();
+module.exports.tests.countryAbbreviationSynonymsMultiplexerFilter = (test, common) => {
+  test('has country_abbreviation_synonyms_multiplexer filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.filter.country_abbreviation_synonyms_multiplexer, 'object', 'there is a country_abbreviation_synonyms_multiplexer filter');
-    var filter = s.analysis.filter.country_abbreviation_synonyms_multiplexer;
+    const filter = s.analysis.filter.country_abbreviation_synonyms_multiplexer;
     t.equal(filter.type, 'multiplexer');
     t.deepEqual(filter.filters, [
       'synonyms/country_codes'
@@ -363,11 +363,11 @@ module.exports.tests.countryAbbreviationSynonymsMultiplexerFilter = function (te
 
 // this multiplexer filter provides all the synonyms used by the peliasPhrase and peliasIndexOneEdgeGram analyzers
 // note: the multiplexer ensures than we do not virally generate synonyms of synonyms.
-module.exports.tests.nameSynonymsMultiplexerFilter = function (test, common) {
-  test('has name_synonyms_multiplexer filter', function (t) {
-    var s = settings();
+module.exports.tests.nameSynonymsMultiplexerFilter = (test, common) => {
+  test('has name_synonyms_multiplexer filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.filter.name_synonyms_multiplexer, 'object', 'there is a name_synonyms_multiplexer filter');
-    var filter = s.analysis.filter.name_synonyms_multiplexer;
+    const filter = s.analysis.filter.name_synonyms_multiplexer;
     t.equal(filter.type, 'multiplexer');
     t.deepEqual(filter.filters, [
       'synonyms/custom_name',
@@ -386,11 +386,11 @@ module.exports.tests.nameSynonymsMultiplexerFilter = function (test, common) {
 
 // this multiplexer filter provides all the synonyms used by the peliasStreet analyzer
 // note: the multiplexer ensures than we do not virally generate synonyms of synonyms.
-module.exports.tests.streetSynonymsMultiplexerFilter = function (test, common) {
-  test('has street_synonyms_multiplexer filter', function (t) {
-    var s = settings();
+module.exports.tests.streetSynonymsMultiplexerFilter = (test, common) => {
+  test('has street_synonyms_multiplexer filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.filter.street_synonyms_multiplexer, 'object', 'there is a street_synonyms_multiplexer filter');
-    var filter = s.analysis.filter.street_synonyms_multiplexer;
+    const filter = s.analysis.filter.street_synonyms_multiplexer;
     t.equal(filter.type, 'multiplexer');
     t.deepEqual(filter.filters, [
       'synonyms/custom_street',
@@ -404,17 +404,17 @@ module.exports.tests.streetSynonymsMultiplexerFilter = function (test, common) {
 };
 
 // cycle through all analyzers and ensure the corrsponding token filters are globally defined
-module.exports.tests.allTokenFiltersPresent = function(test, common) {
-  var ES_INBUILT_FILTERS = [
+module.exports.tests.allTokenFiltersPresent = (test, common) => {
+  const ES_INBUILT_FILTERS = [
     'lowercase', 'icu_folding', 'trim', 'word_delimiter', 'unique', 'flatten_graph'
   ];
-  test('all token filters present', function(t) {
-    var s = settings();
-    for( var analyzerName in s.analysis.analyzer ){
-      var analyzer = s.analysis.analyzer[analyzerName];
+  test('all token filters present', t => {
+    const s = settings();
+    for( const analyzerName in s.analysis.analyzer ){
+      const analyzer = s.analysis.analyzer[analyzerName];
       if( Array.isArray( analyzer.filter ) ){
-        analyzer.filter.forEach( function( tokenFilterName ){
-          var filterExists = (
+        analyzer.filter.forEach( tokenFilterName => {
+          const filterExists = (
             s.analysis.filter.hasOwnProperty( tokenFilterName ) ||
             ES_INBUILT_FILTERS.includes( tokenFilterName )
           );
@@ -427,16 +427,16 @@ module.exports.tests.allTokenFiltersPresent = function(test, common) {
 };
 
 // cycle through all analyzers and ensure the mandatory token filters are defined on each
-module.exports.tests.mandatoryTokenFiltersPresent = function (test, common) {
-  var MANDATORY_FILTERS = [
+module.exports.tests.mandatoryTokenFiltersPresent = (test, common) => {
+  const MANDATORY_FILTERS = [
     'lowercase', 'icu_folding', 'trim', 'unique_only_same_position', 'notnull'
   ];
-  test('mandatory filters present', function (t) {
-    var s = settings();
-    for (var analyzerName in s.analysis.analyzer) {
-      var analyzer = s.analysis.analyzer[analyzerName];
+  test('mandatory filters present', t => {
+    const s = settings();
+    for (const analyzerName in s.analysis.analyzer) {
+      const analyzer = s.analysis.analyzer[analyzerName];
       if (Array.isArray(analyzer.filter)) {
-        MANDATORY_FILTERS.forEach(function (filterName) {
+        MANDATORY_FILTERS.forEach(filterName => {
           t.true(
             analyzer.filter.includes(filterName),
             `mandatory token filter ${filterName} not defined on ${analyzerName}`
@@ -449,16 +449,16 @@ module.exports.tests.mandatoryTokenFiltersPresent = function (test, common) {
 };
 
 // cycle through all analyzers and ensure the corrsponding character filters are defined
-module.exports.tests.allCharacterFiltersPresent = function(test, common) {
-  var ES_INBUILT_FILTERS = [];
-  test('all character filters present', function(t) {
-    var s = settings();
-    for( var analyzerName in s.analysis.analyzer ){
-      var analyzer = s.analysis.analyzer[analyzerName];
+module.exports.tests.allCharacterFiltersPresent = (test, common) => {
+  const ES_INBUILT_FILTERS = [];
+  test('all character filters present', t => {
+    const s = settings();
+    for( const analyzerName in s.analysis.analyzer ){
+      const analyzer = s.analysis.analyzer[analyzerName];
       if( Array.isArray( analyzer.char_filter ) ){
-        analyzer.char_filter.forEach( function( charFilterName ){
-          var filterExists = s.analysis.char_filter.hasOwnProperty( charFilterName );
-          if( !filterExists && -1 < ES_INBUILT_FILTERS.indexOf( charFilterName ) ){
+        analyzer.char_filter.forEach( charFilterName => {
+          let filterExists = s.analysis.char_filter.hasOwnProperty( charFilterName );
+          if( !filterExists && ES_INBUILT_FILTERS.includes(charFilterName) ){
             filterExists = true;
           }
           t.true( filterExists, 'missing character filter: ' + charFilterName );
@@ -473,11 +473,11 @@ module.exports.tests.allCharacterFiltersPresent = function(test, common) {
 
 // note: pattern/replace should not have surrounding whitespace
 // we convert and->& rather than &->and to save memory/disk
-module.exports.tests.punctuationFilter = function(test, common) {
-  test('has punctuation filter', function(t) {
-    var s = settings();
+module.exports.tests.punctuationFilter = (test, common) => {
+  test('has punctuation filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.filter['synonyms/punctuation'], 'object', 'there is a punctuation filter');
-    var filter = s.analysis.filter['synonyms/punctuation'];
+    const filter = s.analysis.filter['synonyms/punctuation'];
     t.equal(filter.type, 'synonym');
     t.deepEqual(filter.synonyms, [
       "&,and",
@@ -489,11 +489,11 @@ module.exports.tests.punctuationFilter = function(test, common) {
 
 // this filter simply removes empty tokens which can occur when other
 // filters do weird things, so just to be sure, we explicitly get rid of them
-module.exports.tests.notnullFilter = function(test, common) {
-  test('has notnull filter', function(t) {
-    var s = settings();
+module.exports.tests.notnullFilter = (test, common) => {
+  test('has notnull filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.filter.notnull, 'object', 'there is a notnull filter');
-    var filter = s.analysis.filter.notnull;
+    const filter = s.analysis.filter.notnull;
     t.equal(filter.type, 'length');
     t.equal(filter.min, 1);
     t.end();
@@ -501,11 +501,11 @@ module.exports.tests.notnullFilter = function(test, common) {
 };
 
 // this filter creates edgeNGrams with the minimum size of 1
-module.exports.tests.peliasOneEdgeGramFilter = function(test, common) {
-  test('has peliasIndexOneEdgeGram filter', function(t) {
-    var s = settings();
+module.exports.tests.peliasOneEdgeGramFilter = (test, common) => {
+  test('has peliasIndexOneEdgeGram filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.filter.peliasOneEdgeGramFilter, 'object', 'there is a peliasIndexOneEdgeGram filter');
-    var filter = s.analysis.filter.peliasOneEdgeGramFilter;
+    const filter = s.analysis.filter.peliasOneEdgeGramFilter;
     t.equal(filter.type, 'edge_ngram');
     t.equal(filter.min_gram, 1);
     t.equal(filter.max_gram, 24);
@@ -515,11 +515,11 @@ module.exports.tests.peliasOneEdgeGramFilter = function(test, common) {
 
 // this filter provides synonyms for street suffixes
 // eg. road=>rd
-module.exports.tests.streetSynonymFilter = function(test, common) {
-  test('has synonyms/streets filter', function(t) {
-    var s = settings();
+module.exports.tests.streetSynonymFilter = (test, common) => {
+  test('has synonyms/streets filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.filter['synonyms/streets'], 'object', 'there is a synonyms/streets filter');
-    var filter = s.analysis.filter['synonyms/streets'];
+    const filter = s.analysis.filter['synonyms/streets'];
     t.equal(filter.type, 'synonym');
     t.true(Array.isArray(filter.synonyms));
     t.equal(filter.synonyms.length, 809);
@@ -529,11 +529,11 @@ module.exports.tests.streetSynonymFilter = function(test, common) {
 
 // this filter stems common directional terms
 // eg. north=>n and south=>s
-module.exports.tests.directionalSynonymFilter = function(test, common) {
-  test('has directionals filter', function(t) {
-    var s = settings();
+module.exports.tests.directionalSynonymFilter = (test, common) => {
+  test('has directionals filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.filter['synonyms/directionals'], 'object', 'there is a synonyms/directionals filter');
-    var filter = s.analysis.filter['synonyms/directionals'];
+    const filter = s.analysis.filter['synonyms/directionals'];
     t.equal(filter.type, 'synonym');
     t.true(Array.isArray(filter.synonyms));
     t.equal(filter.synonyms.length, 69);
@@ -543,11 +543,11 @@ module.exports.tests.directionalSynonymFilter = function(test, common) {
 
 // this filter provides common synonyms for personal titles
 // eg. doctor=>dr
-module.exports.tests.personalTitleSynonymFilter = function (test, common) {
-  test('has personal_titles filter', function (t) {
-    var s = settings();
+module.exports.tests.personalTitleSynonymFilter = (test, common) => {
+  test('has personal_titles filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.filter['synonyms/personal_titles'], 'object', 'there is a synonyms/personal_titles filter');
-    var filter = s.analysis.filter['synonyms/personal_titles'];
+    const filter = s.analysis.filter['synonyms/personal_titles'];
     t.equal(filter.type, 'synonym');
     t.true(Array.isArray(filter.synonyms));
     t.equal(filter.synonyms.length, 191);
@@ -557,11 +557,11 @@ module.exports.tests.personalTitleSynonymFilter = function (test, common) {
 
 // this filter provides common synonyms for place names
 // eg. park=>pk
-module.exports.tests.placeNameSynonymFilter = function (test, common) {
-  test('has place_names filter', function (t) {
-    var s = settings();
+module.exports.tests.placeNameSynonymFilter = (test, common) => {
+  test('has place_names filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.filter['synonyms/place_names'], 'object', 'there is a synonyms/place_names filter');
-    var filter = s.analysis.filter['synonyms/place_names'];
+    const filter = s.analysis.filter['synonyms/place_names'];
     t.equal(filter.type, 'synonym');
     t.true(Array.isArray(filter.synonyms));
     t.equal(filter.synonyms.length, 314);
@@ -571,11 +571,11 @@ module.exports.tests.placeNameSynonymFilter = function (test, common) {
 
 // this filter removes number ordinals
 // eg. 26th => 26, 1st => 1
-module.exports.tests.removeOrdinalsFilter = function(test, common) {
-  test('has remove_ordinals filter', function(t) {
-    var s = settings();
+module.exports.tests.removeOrdinalsFilter = (test, common) => {
+  test('has remove_ordinals filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.filter.remove_ordinals, 'object', 'there is an remove_ordinals filter');
-    var filter = s.analysis.filter.remove_ordinals;
+    const filter = s.analysis.filter.remove_ordinals;
     t.equal(filter.type, 'pattern_replace');
     t.equal(filter.pattern, '(?i)((^| )((1)st?|(2)nd?|(3)rd?|([4-9])th?)|(([0-9]*)(1[0-9])th?)|(([0-9]*[02-9])((1)st?|(2)nd?|(3)rd?|([04-9])th?))($| ))');
     t.equal(filter.replacement, '$2$4$5$6$7$9$10$12$14$15$16$17$18');
@@ -587,11 +587,11 @@ module.exports.tests.removeOrdinalsFilter = function(test, common) {
 
 // we use a custom punctuation filter in order to allow the ampersand
 // character which would otherwise be stripped by the standard tokenizer
-module.exports.tests.punctuationCharFilter = function(test, common) {
-  test('has punctuation char_filter', function(t) {
-    var s = settings();
+module.exports.tests.punctuationCharFilter = (test, common) => {
+  test('has punctuation char_filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.char_filter.punctuation, 'object', 'there is a punctuation char_filter');
-    var char_filter = s.analysis.char_filter.punctuation;
+    const char_filter = s.analysis.char_filter.punctuation;
     t.equal(char_filter.type, 'mapping');
     t.true(Array.isArray(char_filter.mappings));
     t.equal(char_filter.mappings.length, 59);
@@ -600,11 +600,11 @@ module.exports.tests.punctuationCharFilter = function(test, common) {
 };
 
 // remove non alphanumeric characters
-module.exports.tests.alphanumericCharFilter = function(test, common) {
-  test('has alphanumeric char_filter', function(t) {
-    var s = settings();
+module.exports.tests.alphanumericCharFilter = (test, common) => {
+  test('has alphanumeric char_filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.char_filter.alphanumeric, 'object', 'there is a alphanumeric char_filter');
-    var char_filter = s.analysis.char_filter.alphanumeric;
+    const char_filter = s.analysis.char_filter.alphanumeric;
     t.equal(char_filter.type, 'pattern_replace');
     t.equal(char_filter.pattern, '[^a-zA-Z0-9]');
     t.equal(char_filter.replacement, '');
@@ -613,11 +613,11 @@ module.exports.tests.alphanumericCharFilter = function(test, common) {
 };
 
 // replace non-numeric chars with a space
-module.exports.tests.numericCharFilter = function(test, common) {
-  test('has numeric char_filter', function(t) {
-    var s = settings();
+module.exports.tests.numericCharFilter = (test, common) => {
+  test('has numeric char_filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.char_filter.numeric, 'object', 'there is a numeric char_filter');
-    var char_filter = s.analysis.char_filter.numeric;
+    const char_filter = s.analysis.char_filter.numeric;
     t.equal(char_filter.type, 'pattern_replace');
     t.equal(char_filter.pattern, '[^0-9]');
     t.equal(char_filter.replacement, ' ');
@@ -627,11 +627,11 @@ module.exports.tests.numericCharFilter = function(test, common) {
 
 // this filter provides british/american english synonyms
 // eg. center<=>centre
-module.exports.tests.britishAmericanEnglishSynonymFilter = function (test, common) {
-  test('has british_american_english filter', function (t) {
-    var s = settings();
+module.exports.tests.britishAmericanEnglishSynonymFilter = (test, common) => {
+  test('has british_american_english filter', t => {
+    const s = settings();
     t.equal(typeof s.analysis.filter['synonyms/british_american_english'], 'object', 'there is a synonyms/british_american_english filter');
-    var filter = s.analysis.filter['synonyms/british_american_english'];
+    const filter = s.analysis.filter['synonyms/british_american_english'];
     t.equal(filter.type, 'synonym');
     t.true(Array.isArray(filter.synonyms));
     t.equal(filter.synonyms.length, 255);
@@ -642,9 +642,9 @@ module.exports.tests.britishAmericanEnglishSynonymFilter = function (test, commo
 // -- etc --
 
 // index should always be set
-module.exports.tests.index = function(test, common) {
-  test('has index settings', function(t) {
-    var s = settings();
+module.exports.tests.index = (test, common) => {
+  test('has index settings', t => {
+    const s = settings();
     t.equal(typeof s.index, 'object', 'index specified');
     t.equal(s.index.number_of_replicas, "0", 'replicas will increase index time');
     t.equal(s.index.number_of_shards, "5", 'sharding value should use the elasticsearch default');
@@ -653,12 +653,12 @@ module.exports.tests.index = function(test, common) {
 };
 
 // allow overrides from pelias/config
-module.exports.tests.overrides = function(test, common) {
-  test('override defaults', function(t) {
+module.exports.tests.overrides = (test, common) => {
+  test('override defaults', t => {
 
     process.env['PELIAS_CONFIG'] = path.resolve(__dirname + '/fixtures/empty.json');
 
-    var s = settings();
+    let s = settings();
     t.equal(s.index['number_of_replicas'], '0', 'unchanged');
 
     // set the PELIAS_CONFIG env var
@@ -671,11 +671,11 @@ module.exports.tests.overrides = function(test, common) {
     // unset the PELIAS_CONFIG env var
     delete process.env['PELIAS_CONFIG'];
   });
-  test('override similarity', function (t) {
+  test('override similarity', t => {
 
     process.env['PELIAS_CONFIG'] = path.resolve(__dirname + '/fixtures/empty.json');
 
-    var s = settings();
+    let s = settings();
     t.equal(s.index.similarity.peliasDefaultSimilarity.k1, 1.2, 'unchanged');
 
     // set the PELIAS_CONFIG env var
@@ -691,13 +691,13 @@ module.exports.tests.overrides = function(test, common) {
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('settings: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };
diff --git a/test/synonyms/parser.js b/test/synonyms/parser.js
index 6ce2d201..cd46acaf 100644
--- a/test/synonyms/parser.js
+++ b/test/synonyms/parser.js
@@ -2,20 +2,20 @@ const parser = require('../../synonyms/parser');
 
 module.exports.tests = {};
 
-module.exports.tests.load = function(test, common) {
-  test('load: invalid file', function(t) {
+module.exports.tests.load = (test, common) => {
+  test('load: invalid file', t => {
     t.throws(() => parser('/invalid/path'), /file not found/, 'invalid file');
     t.throws(() => parser('/tmp'), /file not found/, 'directory');
     t.end();
   });
 };
 
-module.exports.tests.parse = function(test, common) {
-  test('empty file', function(t) {
+module.exports.tests.parse = (test, common) => {
+  test('empty file', t => {
     t.deepEqual( parser.parse(``), [] );
     t.end();
   });
-  test('comments and newlines', function(t) {
+  test('comments and newlines', t => {
     t.deepEqual( parser.parse(`
 
 # foo bar
@@ -25,7 +25,7 @@ module.exports.tests.parse = function(test, common) {
 `), [] );
     t.end();
   });
-  test('lowercase', function(t) {
+  test('lowercase', t => {
     t.deepEqual( parser.parse(`
 Foo => BaR
 Foo,Bar,Baz
@@ -35,7 +35,7 @@ Foo,Bar,Baz
 ] );
     t.end();
   });
-  test('squash spaces', function(t) {
+  test('squash spaces', t => {
     t.deepEqual( parser.parse(`
 foo  bar => foo
 Foo  Bar, Foo
@@ -45,7 +45,7 @@ Foo  Bar, Foo
 ] );
     t.end();
   });
-  test('trim commas', function(t) {
+  test('trim commas', t => {
     t.deepEqual( parser.parse(`
 ,foo => bar
 ,foo, bar,
@@ -55,7 +55,7 @@ Foo  Bar, Foo
 ] );
     t.end();
   });
-  test('trim around commas', function(t) {
+  test('trim around commas', t => {
     t.deepEqual( parser.parse(`
  ,foo, bar , baz
 `), [
@@ -63,7 +63,7 @@ Foo  Bar, Foo
 ] );
     t.end();
   });
-  test('trim around arrows', function(t) {
+  test('trim around arrows', t => {
     t.deepEqual( parser.parse(`
   foo  =>   bar
 `), [
@@ -73,13 +73,13 @@ Foo  Bar, Foo
   });
 };
 
-module.exports.all = function (tape, common) {
+module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
     return tape('synonyms parser: ' + name, testFunction);
   }
 
-  for( var testCase in module.exports.tests ){
+  for( const testCase in module.exports.tests ){
     module.exports.tests[testCase](test, common);
   }
 };

From 5b11d82521b0e866aba3e6ba5901cd7aea3aa991 Mon Sep 17 00:00:00 2001
From: Siarhei Fedartsou <siarhei.fedartsou@gmail.com>
Date: Sat, 1 Mar 2025 18:23:50 +0100
Subject: [PATCH 2/3] Modernize codebase

---
 scripts/list_analyzers.js | 6 +++---
 test/compile.js           | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/scripts/list_analyzers.js b/scripts/list_analyzers.js
index 6adaffa9..04abf53d 100644
--- a/scripts/list_analyzers.js
+++ b/scripts/list_analyzers.js
@@ -83,14 +83,14 @@ const property = (prop, field) => {
       // more than one dynamic template matches
       } else if (matches.length > 1) {
         error({
-          field: field,
+          field,
           message: 'multiple dynamic_templates matched'
         })
 
       // no properties object or dynamic template matched
       } else {
         error({
-          field: field,
+          field,
           message: 'missing object properties'
         })
       }
@@ -98,7 +98,7 @@ const property = (prop, field) => {
   } else {
     // scalar property definition
     print({
-      field: field,
+      field,
       type: prop.type,
       analyzer: prop.analyzer || defaultAnalyzerFor(prop),
       search_analyzer: prop.search_analyzer || prop.analyzer || defaultAnalyzerFor(prop),
diff --git a/test/compile.js b/test/compile.js
index 05b9109b..c77d7e13 100644
--- a/test/compile.js
+++ b/test/compile.js
@@ -85,7 +85,7 @@ module.exports.tests.analyzers = (test, common) => {
     forEachDeep(schema, (value, key) => {
       if (!_.isPlainObject(value)) { return; }
       if (!stringyTypes.includes(_.get(value, 'type', ''))) { return; }
-      stringyFields.push({ key: key, value: value });
+      stringyFields.push({ key, value });
     });
 
     stringyFields.forEach(field => {

From 0a3786ad486abdd4aa30f41dae24563d58763d21 Mon Sep 17 00:00:00 2001
From: Siarhei Fedartsou <siarhei.fedartsou@gmail.com>
Date: Sat, 1 Mar 2025 18:26:39 +0100
Subject: [PATCH 3/3] Use string template where possible

---
 settings.js               |  2 +-
 test/compile.js           |  6 +++---
 test/configValidation.js  |  2 +-
 test/document.js          | 22 +++++++++++-----------
 test/elastictest/Suite.js |  2 +-
 test/partial-admin.js     |  2 +-
 test/partial-centroid.js  |  2 +-
 test/partial-hash.js      |  2 +-
 test/partial-keyword.js   |  2 +-
 test/settings.js          | 14 +++++++-------
 test/synonyms/parser.js   |  2 +-
 11 files changed, 29 insertions(+), 29 deletions(-)

diff --git a/settings.js b/settings.js
index 5208e4fb..2323edc6 100644
--- a/settings.js
+++ b/settings.js
@@ -243,7 +243,7 @@ function generate(){
       "char_filter": {
         "punctuation" : {
           "type" : "mapping",
-          "mappings" : punctuation.blacklist.map(c => c + '=>')
+          "mappings" : punctuation.blacklist.map(c => `${c}=>`)
         },
         "alphanumeric" : {
           "type" : "pattern_replace",
diff --git a/test/compile.js b/test/compile.js
index c77d7e13..921c4dd6 100644
--- a/test/compile.js
+++ b/test/compile.js
@@ -119,7 +119,7 @@ module.exports.tests.current_schema = (test, common) => {
     const schemaCopy = JSON.parse( JSON.stringify( schema ) );
 
     // use the pelias config fixture instead of the local config
-    overridePeliasConfig(path.resolve( __dirname + '/fixtures/config.json' ), () => {
+    overridePeliasConfig(path.resolve( `${__dirname}/fixtures/config.json` ), () => {
       schemaCopy.settings = require('../settings')();
     });
 
@@ -141,7 +141,7 @@ module.exports.tests.current_schema = (test, common) => {
     const schemaCopy = JSON.parse( JSON.stringify( schema ) );
 
     // use the pelias config fixture instead of the local config
-    overridePeliasConfig(path.resolve( __dirname + '/fixtures/config-icu-tokenizer.json' ), () => {
+    overridePeliasConfig(path.resolve( `${__dirname}/fixtures/config-icu-tokenizer.json` ), () => {
       schemaCopy.settings = require('../settings')();
     });
 
@@ -161,7 +161,7 @@ module.exports.tests.current_schema = (test, common) => {
 module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
-    return tape('compile: ' + name, testFunction);
+    return tape(`compile: ${name}`, testFunction);
   }
 
   for( const testCase in module.exports.tests ){
diff --git a/test/configValidation.js b/test/configValidation.js
index 66cb33d9..fa7b5b88 100644
--- a/test/configValidation.js
+++ b/test/configValidation.js
@@ -89,7 +89,7 @@ module.exports.tests.interface = (test, common) => {
 module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
-    return tape('configValidation: ' + name, testFunction);
+    return tape(`configValidation: ${name}`, testFunction);
   }
 
   for( const testCase in module.exports.tests ){
diff --git a/test/document.js b/test/document.js
index d004a685..6c9ddb1e 100644
--- a/test/document.js
+++ b/test/document.js
@@ -145,12 +145,12 @@ module.exports.tests.parent_analysis = (test, common) => {
       let expectedNgramSearchAnalyzer = 'peliasAdmin';
 
       // id field
-      t.equal(prop[field+'_id'].type, 'keyword', `${field}_id type is keyword`);
-      t.equal(prop[field+'_id'].index, undefined, `${field}_id index left at default`);
+      t.equal(prop[`${field}_id`].type, 'keyword', `${field}_id type is keyword`);
+      t.equal(prop[`${field}_id`].index, undefined, `${field}_id index left at default`);
 
       // source field
-      t.equal(prop[field + '_source'].type, 'keyword', `${field}_source type is keyword`);
-      t.equal(prop[field + '_source'].index, undefined, `${field}_source index left at default`);
+      t.equal(prop[`${field}_source`].type, 'keyword', `${field}_source type is keyword`);
+      t.equal(prop[`${field}_source`].index, undefined, `${field}_source index left at default`);
 
       // fulltext field eg. parent.region
       t.equal(prop[field].type, 'text', `${field} is set to text type`);
@@ -172,14 +172,14 @@ module.exports.tests.parent_analysis = (test, common) => {
       }
 
       // abbreviaton
-      t.equal(prop[field + '_a'].type, 'text', `${field}_a type is text`);
-      t.equal(prop[field + '_a'].analyzer, expectedFullTextIndexAnalyzer, `${field}_a analyzer`);
-      t.equal(prop[field + '_a'].search_analyzer, expectedFullTextSearchAnalyzer, `${field}_a analyzer`);
+      t.equal(prop[`${field}_a`].type, 'text', `${field}_a type is text`);
+      t.equal(prop[`${field}_a`].analyzer, expectedFullTextIndexAnalyzer, `${field}_a analyzer`);
+      t.equal(prop[`${field}_a`].search_analyzer, expectedFullTextSearchAnalyzer, `${field}_a analyzer`);
 
       // abbreviaton ngram subfield
-      t.equal(prop[field + '_a'].fields.ngram.type, 'text', `${field}_a.ngram type is full text`);
-      t.equal(prop[field + '_a'].fields.ngram.analyzer, expectedNgramIndexAnalyzer, `${field}_a.ngram analyzer`);
-      t.equal(prop[field + '_a'].fields.ngram.search_analyzer, expectedNgramSearchAnalyzer, `${field}_a.ngram analyzer`);
+      t.equal(prop[`${field}_a`].fields.ngram.type, 'text', `${field}_a.ngram type is full text`);
+      t.equal(prop[`${field}_a`].fields.ngram.analyzer, expectedNgramIndexAnalyzer, `${field}_a.ngram analyzer`);
+      t.equal(prop[`${field}_a`].fields.ngram.search_analyzer, expectedNgramSearchAnalyzer, `${field}_a.ngram analyzer`);
 
       t.end();
     });
@@ -255,7 +255,7 @@ module.exports.tests._source = (test, common) => {
 module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
-    return tape('document: ' + name, testFunction);
+    return tape(`document: ${name}`, testFunction);
   }
 
   for( const testCase in module.exports.tests ){
diff --git a/test/elastictest/Suite.js b/test/elastictest/Suite.js
index 6a52ba68..16114615 100644
--- a/test/elastictest/Suite.js
+++ b/test/elastictest/Suite.js
@@ -13,7 +13,7 @@ function Suite (clientOpts, props) {
   })
   this.props = props || {}
   if (!_.has(this, 'props.index')) {
-    this.props.index = 'testindex-' + randomstring.generate(7).toLowerCase()
+    this.props.index = `testindex-${randomstring.generate(7).toLowerCase()}`
   }
 }
 
diff --git a/test/partial-admin.js b/test/partial-admin.js
index bee5ae6d..bdb094a8 100644
--- a/test/partial-admin.js
+++ b/test/partial-admin.js
@@ -45,7 +45,7 @@ module.exports.tests.analysis = (test, common) => {
 module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
-    return tape('admin: ' + name, testFunction);
+    return tape(`admin: ${name}`, testFunction);
   }
 
   for( const testCase in module.exports.tests ){
diff --git a/test/partial-centroid.js b/test/partial-centroid.js
index 8c3d8d7f..7fff502f 100644
--- a/test/partial-centroid.js
+++ b/test/partial-centroid.js
@@ -22,7 +22,7 @@ module.exports.tests.type = (test, common) => {
 module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
-    return tape('centroid: ' + name, testFunction);
+    return tape(`centroid: ${name}`, testFunction);
   }
 
   for( const testCase in module.exports.tests ){
diff --git a/test/partial-hash.js b/test/partial-hash.js
index 1338db8b..e6df5319 100644
--- a/test/partial-hash.js
+++ b/test/partial-hash.js
@@ -30,7 +30,7 @@ module.exports.tests.dynamic = (test, common) => {
 module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
-    return tape('hash: ' + name, testFunction);
+    return tape(`hash: ${name}`, testFunction);
   }
 
   for( const testCase in module.exports.tests ){
diff --git a/test/partial-keyword.js b/test/partial-keyword.js
index 62587cd3..fce32d48 100644
--- a/test/partial-keyword.js
+++ b/test/partial-keyword.js
@@ -36,7 +36,7 @@ module.exports.tests.analysis = (test, common) => {
 module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
-    return tape('keyword: ' + name, testFunction);
+    return tape(`keyword: ${name}`, testFunction);
   }
 
   for( const testCase in module.exports.tests ){
diff --git a/test/settings.js b/test/settings.js
index dc95ac19..3d175d21 100644
--- a/test/settings.js
+++ b/test/settings.js
@@ -418,7 +418,7 @@ module.exports.tests.allTokenFiltersPresent = (test, common) => {
             s.analysis.filter.hasOwnProperty( tokenFilterName ) ||
             ES_INBUILT_FILTERS.includes( tokenFilterName )
           );
-          t.true( filterExists, 'token filter exists: ' + tokenFilterName );
+          t.true( filterExists, `token filter exists: ${tokenFilterName}` );
         });
       }
     }
@@ -461,7 +461,7 @@ module.exports.tests.allCharacterFiltersPresent = (test, common) => {
           if( !filterExists && ES_INBUILT_FILTERS.includes(charFilterName) ){
             filterExists = true;
           }
-          t.true( filterExists, 'missing character filter: ' + charFilterName );
+          t.true( filterExists, `missing character filter: ${charFilterName}` );
         });
       }
     }
@@ -656,13 +656,13 @@ module.exports.tests.index = (test, common) => {
 module.exports.tests.overrides = (test, common) => {
   test('override defaults', t => {
 
-    process.env['PELIAS_CONFIG'] = path.resolve(__dirname + '/fixtures/empty.json');
+    process.env['PELIAS_CONFIG'] = path.resolve(`${__dirname}/fixtures/empty.json`);
 
     let s = settings();
     t.equal(s.index['number_of_replicas'], '0', 'unchanged');
 
     // set the PELIAS_CONFIG env var
-    process.env['PELIAS_CONFIG'] = path.resolve( __dirname + '/fixtures/config.json' );
+    process.env['PELIAS_CONFIG'] = path.resolve( `${__dirname}/fixtures/config.json` );
 
     s = settings();
     t.equal(s.index['number_of_replicas'], '999', 'changed');
@@ -673,13 +673,13 @@ module.exports.tests.overrides = (test, common) => {
   });
   test('override similarity', t => {
 
-    process.env['PELIAS_CONFIG'] = path.resolve(__dirname + '/fixtures/empty.json');
+    process.env['PELIAS_CONFIG'] = path.resolve(`${__dirname}/fixtures/empty.json`);
 
     let s = settings();
     t.equal(s.index.similarity.peliasDefaultSimilarity.k1, 1.2, 'unchanged');
 
     // set the PELIAS_CONFIG env var
-    process.env['PELIAS_CONFIG'] = path.resolve(__dirname + '/fixtures/similarity.json');
+    process.env['PELIAS_CONFIG'] = path.resolve(`${__dirname}/fixtures/similarity.json`);
 
     s = settings();
     t.equal(s.index.similarity.peliasDefaultSimilarity.k1, 0, 'changed');
@@ -694,7 +694,7 @@ module.exports.tests.overrides = (test, common) => {
 module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
-    return tape('settings: ' + name, testFunction);
+    return tape(`settings: ${name}`, testFunction);
   }
 
   for( const testCase in module.exports.tests ){
diff --git a/test/synonyms/parser.js b/test/synonyms/parser.js
index cd46acaf..2dd1ae05 100644
--- a/test/synonyms/parser.js
+++ b/test/synonyms/parser.js
@@ -76,7 +76,7 @@ Foo  Bar, Foo
 module.exports.all = (tape, common) => {
 
   function test(name, testFunction) {
-    return tape('synonyms parser: ' + name, testFunction);
+    return tape(`synonyms parser: ${name}`, testFunction);
   }
 
   for( const testCase in module.exports.tests ){