feat(makeObjectIterable): Add makeObjectIterable function (#182)

src/index.js

@@ -64,6 +64,7 @@ import isLeapYear from './leap-year'
 import removeElementFromArray from './removeElementFromArray'
 import generatePassword from './generate-password'
 import tail from './tail'
+import makeObjectIterable from './makeObjectIterable'
 
 export {
   reverseArrayInPlace,
@@ -132,4 +133,5 @@ export {
   removeElementFromArray,
   generatePassword,
   tail,
+  makeObjectIterable,
 }

src/makeObjectIterable.js

@@ -0,0 +1,32 @@
+export default makeObjectIterable
+
+/**
+ * Original Source: https://stackoverflow.com/questions/48132121/how-to-make-iterable-object-in-javascript
+ *
+ * Makes a regular object iterable so that it can be used in constructs such
+ * as a for-of loop.
+ *
+ * @param {Object} obj - object on which iteration is desired
+ * @returns {Object} - returns the same object
+ */
+function makeObjectIterable(obj) {
+  Object.defineProperty(obj, Symbol.iterator, {
+    writable: false,
+    enumerable: false,
+    configurable: true,
+    value: function iteratorCreator() {
+      let idx = 0
+      const ks = Object.keys(obj)
+      return {
+        next: function nextElement() {
+          return {
+            value: obj[ks[idx++]],
+            done: idx > ks.length,
+          }
+        },
+      }
+    },
+  })
+
+  return obj
+}

test/makeObjectIterable.test.js

@@ -0,0 +1,14 @@
+import test from 'ava'
+import {makeObjectIterable} from '../src'
+
+test('check if the iterator returns correct values ', t => {
+  const myObj = {a: 1, b: 2, c: 'XKCD'}
+  const out = makeObjectIterable(myObj)
+  const a = []
+  const b = []
+  Object.keys(myObj).map(item => a.push(myObj[item]))
+  for (const v of out) {
+    b.push(v)
+  }
+  t.deepEqual(a, b)
+})