Make outputJson() mutation-proof

Fixes #702

lib/json/__tests__/output-json.test.js

@@ -33,6 +33,26 @@ describe('json', () => {
       })
     })
 
+    it('should be mutation-proof', async () => {
+      const dir = path.join(TEST_DIR, 'this-dir', 'certanly-does-not', 'exist')
+      const file = path.join(dir, 'file.json')
+      assert(!fs.existsSync(dir), 'directory cannot exist')
+
+      const name = 'JP'
+      const data = { name }
+      const promise = fse.outputJson(file, data)
+      // Mutate data right after call
+      data.name = 'Ryan'
+      // now await for the call to finish
+      await promise
+
+      assert(fs.existsSync(file))
+      const newData = JSON.parse(fs.readFileSync(file, 'utf8'))
+
+      // mutation did not change data
+      assert.strictEqual(newData.name, name)
+    })
+
     it('should support Promises', () => {
       const file = path.join(TEST_DIR, 'this-dir', 'prob-does-not', 'exist', 'file.json')
       assert(!fs.existsSync(file))

lib/json/index.js

@@ -1,6 +1,6 @@
 'use strict'
 
-const u = require('universalify').fromCallback
+const u = require('universalify').fromPromise
 const jsonFile = require('./jsonfile')
 
 jsonFile.outputJson = u(require('./output-json'))

lib/json/output-json.js

@@ -1,27 +1,12 @@
 'use strict'
 
-const path = require('path')
-const mkdir = require('../mkdirs')
-const pathExists = require('../path-exists').pathExists
-const jsonFile = require('./jsonfile')
+const { stringify } = require('jsonfile/utils')
+const { outputFile } = require('../output')
 
-function outputJson (file, data, options, callback) {
-  if (typeof options === 'function') {
-    callback = options
-    options = {}
-  }
+async function outputJson (file, data, options = {}) {
+  const str = stringify(data, options)
 
-  const dir = path.dirname(file)
-
-  pathExists(dir, (err, itDoes) => {
-    if (err) return callback(err)
-    if (itDoes) return jsonFile.writeJson(file, data, options, callback)
-
-    mkdir.mkdirs(dir, err => {
-      if (err) return callback(err)
-      jsonFile.writeJson(file, data, options, callback)
-    })
-  })
+  await outputFile(file, str, options)
 }
 
 module.exports = outputJson