Add option to override final EOL in file (#137)

Author: asingh04

.gitignore

@@ -1,2 +1,4 @@
 node_modules/
 /.project
+.vscode/
+

README.md

@@ -77,7 +77,7 @@ console.dir(jsonfile.readFileSync(file))
 
 ### writeFile(filename, obj, [options], callback)
 
-`options`: Pass in any [`fs.writeFile`](https://nodejs.org/api/fs.html#fs_fs_writefile_file_data_options_callback) options or set `replacer` for a [JSON replacer](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify). Can also pass in `spaces` and override `EOL` string.
+`options`: Pass in any [`fs.writeFile`](https://nodejs.org/api/fs.html#fs_fs_writefile_file_data_options_callback) options or set `replacer` for a [JSON replacer](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify). Can also pass in `spaces`, or override `EOL` string or set `finalEOL` flag as `false` to not save the file with `EOL` at the end.
 
 
 ```js
@@ -132,6 +132,20 @@ jsonfile.writeFile(file, obj, { spaces: 2, EOL: '\r\n' }, function (err) {
 })
 ```
 
+
+**disabling the EOL at the end of file:**
+
+```js
+const jsonfile = require('jsonfile')
+
+const file = '/tmp/data.json'
+const obj = { name: 'JP' }
+
+jsonfile.writeFile(file, obj, { spaces: 2, finalEOL: false }, function (err) {
+  if (err) console.log(err)
+})
+```
+
 **appending to an existing JSON file:**
 
 You can use `fs.writeFile` option `{ flag: 'a' }` to achieve this.
@@ -151,7 +165,7 @@ jsonfile.writeFile(file, obj, { flag: 'a' }, function (err) {
 
 ### writeFileSync(filename, obj, [options])
 
-`options`: Pass in any [`fs.writeFileSync`](https://nodejs.org/api/fs.html#fs_fs_writefilesync_file_data_options) options or set `replacer` for a [JSON replacer](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify). Can also pass in `spaces` and override `EOL` string.
+`options`: Pass in any [`fs.writeFileSync`](https://nodejs.org/api/fs.html#fs_fs_writefilesync_file_data_options) options or set `replacer` for a [JSON replacer](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify). Can also pass in `spaces`, or override `EOL` string or set `finalEOL` flag as `false` to not save the file with `EOL` at the end.
 
 ```js
 const jsonfile = require('jsonfile')
@@ -184,6 +198,17 @@ const obj = { name: 'JP' }
 jsonfile.writeFileSync(file, obj, { spaces: 2, EOL: '\r\n' })
 ```
 
+**disabling the EOL at the end of file:**
+
+```js
+const jsonfile = require('jsonfile')
+
+const file = '/tmp/data.json'
+const obj = { name: 'JP' }
+
+jsonfile.writeFileSync(file, obj, { spaces: 2, finalEOL: false })
+```
+
 **appending to an existing JSON file:**
 
 You can use `fs.writeFileSync` option `{ flag: 'a' }` to achieve this.

test/write-file-sync.test.js

@@ -82,4 +82,38 @@ describe('+ writeFileSync()', () => {
       assert.strictEqual(data, `${JSON.stringify(obj)}\n`)
     })
   })
+  describe('> when EOF option is set to a falsey value', () => {
+    beforeEach((done) => {
+      TEST_DIR = path.join(os.tmpdir(), 'jsonfile-tests-writefile-sync')
+      rimraf.sync(TEST_DIR)
+      fs.mkdir(TEST_DIR, done)
+    })
+
+    afterEach((done) => {
+      rimraf.sync(TEST_DIR)
+      done()
+    })
+
+    it('should not have a the EOL symbol at the end of file', (done) => {
+      const file = path.join(TEST_DIR, 'somefile2.json')
+      const obj = { name: 'jp' }
+      jf.writeFileSync(file, obj, { finalEOL: false })
+      const rawData = fs.readFileSync(file, 'utf8')
+      const data = JSON.parse(rawData)
+      assert.strictEqual(rawData[rawData.length - 1], '}')
+      assert.strictEqual(data.name, obj.name)
+      done()
+    })
+
+    it('should have a the EOL symbol at the end of file when finalEOL is a truth value in options', (done) => {
+      const file = path.join(TEST_DIR, 'somefile2.json')
+      const obj = { name: 'jp' }
+      jf.writeFileSync(file, obj, { finalEOL: true })
+      const rawData = fs.readFileSync(file, 'utf8')
+      const data = JSON.parse(rawData)
+      assert.strictEqual(rawData[rawData.length - 1], '\n')
+      assert.strictEqual(data.name, obj.name)
+      done()
+    })
+  })
 })

test/write-file.test.js

@@ -199,6 +199,47 @@ describe('+ writeFile()', () => {
     })
   })
 
+  describe('> when EOF option is set to a falsey value', () => {
+    beforeEach((done) => {
+      TEST_DIR = path.join(os.tmpdir(), 'jsonfile-tests-writefile')
+      rimraf.sync(TEST_DIR)
+      fs.mkdir(TEST_DIR, done)
+    })
+
+    afterEach((done) => {
+      rimraf.sync(TEST_DIR)
+      done()
+    })
+
+    it('should not have a the EOL symbol at the end of file', (done) => {
+      const file = path.join(TEST_DIR, 'somefile2.json')
+      const obj = { name: 'jp' }
+      jf.writeFile(file, obj, { finalEOL: false }, (err) => {
+        assert.ifError(err)
+        fs.readFile(file, 'utf8', (_, rawData) => {
+          const data = JSON.parse(rawData)
+          assert.strictEqual(rawData[rawData.length - 1], '}')
+          assert.strictEqual(data.name, obj.name)
+          done()
+        })
+      })
+    })
+
+    it('should have a the EOL symbol at the end of file when finalEOL is a truth value in options', (done) => {
+      const file = path.join(TEST_DIR, 'somefile2.json')
+      const obj = { name: 'jp' }
+      jf.writeFile(file, obj, { finalEOL: true }, (err) => {
+        assert.ifError(err)
+        fs.readFile(file, 'utf8', (_, rawData) => {
+          const data = JSON.parse(rawData)
+          assert.strictEqual(rawData[rawData.length - 1], '\n')
+          assert.strictEqual(data.name, obj.name)
+          done()
+        })
+      })
+    })
+  })
+
   // Prevent https://github.com/jprichardson/node-jsonfile/issues/81 from happening
   describe("> when callback isn't passed & can't serialize", () => {
     it('should not write an empty file, should reject the promise', function (done) {

utils.js

@@ -1,9 +1,8 @@
-function stringify (obj, options = {}) {
-  const EOL = options.EOL || '\n'
+function stringify (obj, { EOL = '\n', finalEOL = true, replacer = null, spaces } = {}) {
+  const EOF = finalEOL ? EOL : ''
+  const str = JSON.stringify(obj, replacer, spaces)
 
-  const str = JSON.stringify(obj, options ? options.replacer : null, options.spaces)
-
-  return str.replace(/\n/g, EOL) + EOL
+  return str.replace(/\n/g, EOL) + EOF
 }
 
 function stripBom (content) {