removed mutation of prototype object

Author: zashraf1985

packages/optimizely-sdk/lib/index.browser.js

@@ -25,7 +25,6 @@ var loggerPlugin = require('./plugins/logger');
 var Optimizely = require('./optimizely');
 var eventProcessorConfigValidator = require('./utils/event_processor_config_validator');
 
-fns.applyPolyfills();
 var logger = logging.getLogger();
 logging.setLogHandler(loggerPlugin.createLogger());
 logging.setLogLevel(logging.LogLevel.INFO);

packages/optimizely-sdk/lib/utils/fns/index.js

@@ -17,41 +17,28 @@ var uuid = require('uuid');
 var _isFinite = require('lodash/isFinite');
 var MAX_NUMBER_LIMIT = Math.pow(2, 53);
 
-// Polyfills for older browsers
-var applyPolyfills = function() {
-  if (typeof Object.assign !== 'function') {
-    // Must be writable: true, enumerable: false, configurable: true
-    Object.defineProperty(Object, "assign", {
-      value: function assign(target) {
-        'use strict';
-        if (target === null || target === undefined) {
-          throw new TypeError('Cannot convert undefined or null to object');
-        }
-        var to = Object(target);
-        for (var index = 1; index < arguments.length; index++) {
-          var nextSource = arguments[index];
-
-          if (nextSource !== null && nextSource !== undefined) { 
-            for (var nextKey in nextSource) {
-              // Avoid bugs when hasOwnProperty is shadowed
-              if (Object.prototype.hasOwnProperty.call(nextSource, nextKey)) {
-                to[nextKey] = nextSource[nextKey];
-              }
+module.exports = {
+  assign: function (target) {
+    if (!target) {
+      return {};
+    }
+    if (typeof Object.assign === 'function') {
+      return Object.assign.apply(Object, arguments);
+    } else {
+      var to = Object(target);
+      for (var index = 1; index < arguments.length; index++) {
+        var nextSource = arguments[index];
+        if (nextSource !== null && nextSource !== undefined) { 
+          for (var nextKey in nextSource) {
+            // Avoid bugs when hasOwnProperty is shadowed
+            if (Object.prototype.hasOwnProperty.call(nextSource, nextKey)) {
+              to[nextKey] = nextSource[nextKey];
             }
           }
         }
-        return to;
-      },
-      writable: true,
-      configurable: true
-    });
-  }
-}
-
-module.exports = {
-  assign: function (target) {
-    // Object.assign crashes if target object is undefined or null
-    return target ? Object.assign.apply(Object, arguments) : {};
+      }
+      return to;
+    }
   },
   assignIn: require('lodash/assignIn'),
   cloneDeep: require('lodash/cloneDeep'),
@@ -68,7 +55,6 @@ module.exports = {
     return uuid.v4();
   },
   values: require('lodash/values'),
-  applyPolyfills: applyPolyfills,
   isNumber: function(value) {
     return typeof value === 'number';
   },