feat: add getJsonFromGit method to the API

Author: bahmutov

README.md

@@ -94,6 +94,20 @@ steps:
 
 ## API
 
+### getJsonFromGit
+
+Extracts JSON block from the current Git message text
+
+```js
+const {getJsonFromGit} = require('commit-message-install')
+getJsonFromGit()
+    .then(json => {
+        // {platform: 'win32', packages: 'foo', branch: 'test-branch'}
+    })
+```
+
+### getInstallJson
+
 You can form good Json object to be included in markdown `json` block in the body of
 the commit message using provided function
 

__snapshots__/commit-message-install-spec.js

@@ -126,3 +126,8 @@ exports['commit-message-install getJsonBlock returns json with branch 1'] = {
   "foo": "bar",
   "branch": "test-branch"
 }
+
+exports['commit-message-install getJsonFromGit extracts the json from git message 1'] = {
+  "platform": "win32",
+  "branch": "some-branch"
+}

src/commit-message-install-spec.js

@@ -3,16 +3,20 @@
 /* eslint-env mocha */
 const getMessage = require('.').getMessage
 const getJsonBlock = require('.').getJsonBlock
+const getJsonFromGit = require('.').getJsonFromGit
+
 const la = require('lazy-ass')
 const is = require('check-more-types')
 const stripIndent = require('common-tags').stripIndent
 const snapshot = require('snap-shot-it')
 const stubSpawnShellOnce = require('stub-spawn-once').stubSpawnShellOnce
 
 describe('commit-message-install', () => {
+  const getMessageGitCommand = 'git show -s --pretty=%b'
+
   context('gets last commit message', () => {
     beforeEach(() => {
-      stubSpawnShellOnce('git show -s --pretty=%b', 0, 'message body', '')
+      stubSpawnShellOnce(getMessageGitCommand, 0, 'message body', '')
     })
 
     it('returns just the body of the commit message', () => {
@@ -23,6 +27,30 @@ describe('commit-message-install', () => {
     })
   })
 
+  context('getJsonFromGit', () => {
+    const message = `
+      below is test json block
+
+      \`\`\`json
+      {
+        "platform": "win32",
+        "branch": "some-branch"
+      }
+      \`\`\`
+    `
+    beforeEach(() => {
+      stubSpawnShellOnce(getMessageGitCommand, 0, message, '')
+    })
+
+    it('is a function', () => {
+      la(is.fn(getJsonFromGit))
+    })
+
+    it('extracts the json from git message', () => {
+      getJsonFromGit().then(snapshot)
+    })
+  })
+
   context('--else branch', () => {
     const commitMessageInstall = require('../bin/commit-message-install')
 

src/index.js

@@ -206,12 +206,19 @@ function getInstallJson (packages, env, platform, branch) {
   return json
 }
 
+// looks at the current Git message,
+// extracts JSON block
+function getJsonFromGit () {
+  return getMessage().then(getJsonBlock)
+}
+
 module.exports = {
   getMessage,
   getCommand,
   runIf,
   isPlatformAllowed,
   getJsonBlock,
   npmInstall,
-  getInstallJson
+  getInstallJson,
+  getJsonFromGit
 }