Refactor Data Access Utility (#112)

src/Common/MessageHandler.ts

@@ -9,77 +9,65 @@ export interface CachedDataPromise<T> {
   id: string;
 }
 
-/**
- * For some reason, typescript emits a Map() in the compiled js output(despite the target being set to ES5) forcing us to define our own polyfill,
- * so we define our own custom implementation of the ES6 Map to work around it.
- */
-type Map = { [key: string]: CachedDataPromise<any> };
+export const RequestMap: Record<string, CachedDataPromise<any>> = {};
 
-export class MessageHandler {
-  protected static RequestMap: Map = {};
-
-  public static handleCachedDataMessage(message: any): void {
-    const messageContent = message && message.message;
-    if (
-      message == null ||
-      messageContent == null ||
-      messageContent.id == null ||
-      !MessageHandler.RequestMap[messageContent.id]
-    ) {
-      return;
-    }
-
-    const cachedDataPromise = MessageHandler.RequestMap[messageContent.id];
-    if (messageContent.error != null) {
-      cachedDataPromise.deferred.reject(messageContent.error);
-    } else {
-      cachedDataPromise.deferred.resolve(JSON.parse(messageContent.data));
-    }
-    MessageHandler.runGarbageCollector();
+export function handleCachedDataMessage(message: any): void {
+  const messageContent = message && message.message;
+  if (message == null || messageContent == null || messageContent.id == null || !RequestMap[messageContent.id]) {
+    return;
   }
 
-  public static sendCachedDataMessage<TResponseDataModel>(
-    messageType: MessageTypes,
-    params: Object[],
-    timeoutInMs?: number
-  ): Q.Promise<TResponseDataModel> {
-    let cachedDataPromise: CachedDataPromise<TResponseDataModel> = {
-      deferred: Q.defer<TResponseDataModel>(),
-      startTime: new Date(),
-      id: _.uniqueId()
-    };
-    MessageHandler.RequestMap[cachedDataPromise.id] = cachedDataPromise;
-    MessageHandler.sendMessage({ type: messageType, params: params, id: cachedDataPromise.id });
+  const cachedDataPromise = RequestMap[messageContent.id];
+  if (messageContent.error != null) {
+    cachedDataPromise.deferred.reject(messageContent.error);
+  } else {
+    cachedDataPromise.deferred.resolve(JSON.parse(messageContent.data));
+  }
+  runGarbageCollector();
+}
 
-    //TODO: Use telemetry to measure optimal time to resolve/reject promises
-    return cachedDataPromise.deferred.promise.timeout(
-      timeoutInMs || Constants.ClientDefaults.requestTimeoutMs,
-      "Timed out while waiting for response from portal"
+export function sendCachedDataMessage<TResponseDataModel>(
+  messageType: MessageTypes,
+  params: Object[],
+  timeoutInMs?: number
+): Q.Promise<TResponseDataModel> {
+  let cachedDataPromise: CachedDataPromise<TResponseDataModel> = {
+    deferred: Q.defer<TResponseDataModel>(),
+    startTime: new Date(),
+    id: _.uniqueId()
+  };
+  RequestMap[cachedDataPromise.id] = cachedDataPromise;
+  sendMessage({ type: messageType, params: params, id: cachedDataPromise.id });
+
+  //TODO: Use telemetry to measure optimal time to resolve/reject promises
+  return cachedDataPromise.deferred.promise.timeout(
+    timeoutInMs || Constants.ClientDefaults.requestTimeoutMs,
+    "Timed out while waiting for response from portal"
+  );
+}
+
+export function sendMessage(data: any): void {
+  if (canSendMessage()) {
+    window.parent.postMessage(
+      {
+        signature: "pcIframe",
+        data: data
+      },
+      window.document.referrer
     );
   }
-
-  public static sendMessage(data: any): void {
-    if (MessageHandler.canSendMessage()) {
-      window.parent.postMessage(
-        {
-          signature: "pcIframe",
-          data: data
-        },
-        window.document.referrer
-      );
-    }
-  }
-
-  public static canSendMessage(): boolean {
-    return window.parent !== window;
-  }
-
-  protected static runGarbageCollector() {
-    Object.keys(MessageHandler.RequestMap).forEach((key: string) => {
-      const promise: Q.Promise<any> = MessageHandler.RequestMap[key].deferred.promise;
-      if (promise.isFulfilled() || promise.isRejected()) {
-        delete MessageHandler.RequestMap[key];
-      }
-    });
-  }
+}
+
+export function canSendMessage(): boolean {
+  return window.parent !== window;
+}
+
+// TODO: This is exported just for testing. It should not be.
+export function runGarbageCollector() {
+  Object.keys(RequestMap).forEach((key: string) => {
+    const promise: Q.Promise<any> = RequestMap[key].deferred.promise;
+    if (promise.isFulfilled() || promise.isRejected()) {
+      delete RequestMap[key];
+    }
+  });
 }