Only call functions on existing sibling nodes

Author: Philip von Bargen

src/options/remove-empty-rulesets.js

@@ -25,7 +25,8 @@ module.exports = (function() {
   function mergeAdjacentWhitespace(node) {
     var i = node.content.length - 1;
     while (i-- > 0) {
-      if (node.get(i).is('space') && node.get(i + 1).is('space')) {
+      if (node.get(i).is('space') &&
+          node.get(i + 1) && node.get(i + 1).is('space')) {
         node.get(i).content += node.get(i + 1).content;
         node.removeChild(i + 1);
       }

src/options/space-after-colon.js

@@ -27,7 +27,7 @@ module.exports = {
         return null;
 
       // Remove any spaces after colon:
-      if (parent.get(i + 1).is('space'))
+      if (parent.get(i + 1) && parent.get(i + 1).is('space'))
           parent.removeChild(i + 1);
       // If the value set in config is not empty, add spaces:
       if (value !== '') {
@@ -51,8 +51,10 @@ module.exports = {
     let detected = [];
 
     ast.traverseByType('propertyDelimiter', function(delimiter, i, parent) {
-      if (parent.get(i + 1).is('space')) {
-        detected.push(parent.get(i + 1).content);
+      var nextNode = parent.get(i + 1);
+
+      if (nextNode.is('space')) {
+        detected.push(nextNode.content);
       } else {
         detected.push('');
       }

src/options/space-after-combinator.js

@@ -23,8 +23,10 @@ module.exports = {
     let value = this.value;
 
     ast.traverseByType('combinator', function(combinator, i, parent) {
-      if (parent.get(i + 1).is('space')) {
-        parent.get(i + 1).content = value;
+      var nextNode = parent.get(i + 1);
+
+      if (nextNode && nextNode.is('space')) {
+        nextNode.content = value;
       } else {
         var space = gonzales.createNode({
           type: 'space',
@@ -44,8 +46,10 @@ module.exports = {
     let detected = [];
 
     ast.traverseByType('combinator', function(combinator, i, parent) {
-      if (parent.get(i + 1).is('space')) {
-        detected.push(parent.get(i + 1).content);
+      var nextNode = parent.get(i + 1);
+
+      if (nextNode.is('space')) {
+        detected.push(nextNode.content);
       } else {
         detected.push('');
       }

src/options/space-after-selector-delimiter.js

@@ -26,6 +26,7 @@ module.exports = {
       if (parent.is('arguments')) return;
 
       var nextNode = parent.get(i + 1);
+      if (!nextNode) return;
 
       if (nextNode.is('space')) {
         nextNode.content = value;

src/options/space-before-colon.js

@@ -51,8 +51,10 @@ module.exports = {
     let detected = [];
 
     ast.traverseByType('propertyDelimiter', function(delimiter, i, parent) {
-      if (parent.get(i - 1).is('space')) {
-        detected.push(parent.get(i - 1).content);
+      var previousNode = parent.get(i - 1);
+
+      if (previousNode && previousNode.is('space')) {
+        detected.push(previousNode.content);
       } else {
         detected.push('');
       }

src/options/space-before-combinator.js

@@ -23,8 +23,9 @@ module.exports = {
     let value = this.value;
 
     ast.traverseByType('combinator', function(combinator, i, parent) {
-      if (parent.get(i - 1).is('space')) {
-        parent.get(i - 1).content = value;
+      var previousNode = parent.get(i - 1);
+      if (previousNode && previousNode.is('space')) {
+        previousNode.content = value;
       } else {
         var space = gonzales.createNode({
           type: 'space',
@@ -44,8 +45,10 @@ module.exports = {
     let detected = [];
 
     ast.traverseByType('combinator', function(combinator, i, parent) {
-      if (parent.get(i - 1).is('space')) {
-        detected.push(parent.get(i - 1).content);
+      var previousNode = parent.get(i - 1);
+
+      if (previousNode && previousNode.is('space')) {
+        detected.push(previousNode.content);
       } else {
         detected.push('');
       }

src/options/space-before-selector-delimiter.js

@@ -26,7 +26,8 @@ module.exports = {
       if (parent.is('arguments')) return;
 
       var previousNode = parent.get(i - 1);
-      if (previousNode.is('space')) {
+
+      if (previousNode && previousNode.is('space')) {
         previousNode.content = value;
       } else {
         var space = gonzales.createNode({
@@ -50,7 +51,8 @@ module.exports = {
       if (parent.is('arguments')) return;
 
       var previousNode = parent.get(i - 1);
-      if (previousNode.is('space')) {
+
+      if (previousNode && previousNode.is('space')) {
         detected.push(previousNode.content);
       } else {
         detected.push('');

src/options/space-between-declarations.js

@@ -82,7 +82,7 @@ module.exports = (function() {
         }
 
         var nextNode = parent.get(i + 1);
-        if (nextNode.is('space')) {
+        if (nextNode && nextNode.is('space')) {
           nextNode.content = value;
         } else {
           var space = gonzales.createNode({