Add createSimpleMap factory function to defer SimpleMap creation

Author: lbeschastny

src/simple-map.js

@@ -1,4 +1,4 @@
-export class SimpleMap {
+export const createSimpleMap = () => class SimpleMap {
     constructor () {
         this.size = 0;
         this.keys = [];
@@ -18,8 +18,8 @@ export class SimpleMap {
 
         return value;
     }
-}
+};
 
-const exportedMap = typeof Map === 'undefined' ? SimpleMap : Map;
+const exportedMap = typeof Map === 'undefined' ? createSimpleMap() : Map;
 
 export default exportedMap;

tests/simple-map.js

@@ -1,7 +1,7 @@
 import {
     expect
 } from 'chai';
-import {SimpleMap} from './../src/simple-map';
+import {createSimpleMap} from './../src/simple-map';
 
 const getTests = (map) => {
     return () => {
@@ -28,6 +28,8 @@ const getTests = (map) => {
 };
 
 describe('SimpleMap', () => {
+    const SimpleMap = createSimpleMap();
+
     context('simple map with primitive or object as keys', getTests(new SimpleMap()));
     if (typeof Map !== 'undefined') {
         context('sanity - running tests against native Map', getTests(new Map()));