fix (unit tests): Fix event dispatcher missing in unit test (#256)

Summary:

Optimizely was constructed without an event dispatcher, causing an error to be thrown asynchronously. This fixes the test, and updates the npm test command to make it easier to catch such mistakes - adding a listener for 'unhandledRejection' on process that calls process.exit.

Test plan:

Run unit tests, verify log output.

Author: mjc1283

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

@@ -2451,6 +2451,7 @@ describe('lib/optimizely', function() {
               jsonSchemaValidator: jsonSchemaValidator,
               logger: createdLogger,
               isValidInstance: true,
+              eventDispatcher: eventDispatcher,
             });
 
             optlyInstance.notificationCenter.addNotificationListener(

packages/optimizely-sdk/lib/tests/exit_on_unhandled_rejection.js

@@ -0,0 +1,27 @@
+/**
+ * Copyright 2019, Optimizely
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * This is to stop & fail tests when an unhandled promise rejection occurs.
+ * See: https://nodejs.org/api/process.html#process_event_unhandledrejection
+ */
+process.on('unhandledRejection', function(err) {
+  console.error('Unhandled promise rejection');
+  if (err) {
+    console.error(err);
+  }
+  process.exit(1);
+});

packages/optimizely-sdk/package.json

@@ -6,7 +6,7 @@
   "browser": "lib/index.browser.js",
   "typings": "lib/index.d.ts",
   "scripts": {
-    "test": "mocha ./lib/*.tests.js ./lib/**/*.tests.js ./lib/**/**/*tests.js --recursive --exit",
+    "test": "mocha ./lib/*.tests.js ./lib/**/*.tests.js ./lib/**/**/*tests.js --recursive --exit --require lib/tests/exit_on_unhandled_rejection.js",
     "test-xbrowser": "karma start karma.bs.conf.js --single-run",
     "test-umdbrowser": "npm run build-browser-umd && karma start karma.umd.conf.js --single-run",
     "build-browser-umd": "rm -rf dist && webpack",