remove isBrowser, look for global members instead

microsoft · Jan 14, 2020 · f643429 · f643429
1 parent 28d195c
commit f643429
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Showing 7 changed files with 66 additions and 21 deletions.
diff --git a/libraries/botframework-streaming/src/utilities/doesGlobalFileReaderExist.ts b/libraries/botframework-streaming/src/utilities/doesGlobalFileReaderExist.ts
@@ -0,0 +1,9 @@
+/**
+ * @module botframework-streaming
+ */
+/**
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License.
+ */
+
+export const doesGlobalFileReaderExist = new Function('try {return typeof FileReader !== "undefined" && FileReader !== null;}catch(e){ return false;}');
diff --git a/libraries/botframework-streaming/src/utilities/doesGlobalWebSocketExist.ts b/libraries/botframework-streaming/src/utilities/doesGlobalWebSocketExist.ts
@@ -0,0 +1,9 @@
+/**
+ * @module botframework-streaming
+ */
+/**
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License.
+ */
+
+export const doesGlobalWebSocketExist = new Function('try {return typeof WebSocket !== "undefined" && WebSocket !== null;}catch(e){ return false;}');
diff --git a/libraries/botframework-streaming/src/utilities/index.ts b/libraries/botframework-streaming/src/utilities/index.ts
@@ -6,5 +6,6 @@
  * Licensed under the MIT License.
  */
 
-export * from './isBrowser';
+export * from './doesGlobalFileReaderExist';
+export * from './doesGlobalWebSocketExist';
 export * from './protocol-base';
diff --git a/libraries/botframework-streaming/src/utilities/isBrowser.ts b/libraries/botframework-streaming/src/utilities/isBrowser.ts
diff --git a/libraries/botframework-streaming/src/webSocket/browserWebSocket.ts b/libraries/botframework-streaming/src/webSocket/browserWebSocket.ts
@@ -6,23 +6,23 @@
  * Licensed under the MIT License.
  */
 import { IBrowserFileReader, IBrowserWebSocket, ISocket } from '../interfaces';
-import { isBrowser } from '../utilities';
+import { doesGlobalFileReaderExist, doesGlobalWebSocketExist } from '../utilities';
 
 const createWebSocket = function(url: string): IBrowserWebSocket {
     if (!url) {
         throw new TypeError('Unable to create WebSocket without url.');
     }
-    if (isBrowser()) {
+    if (doesGlobalWebSocketExist()) {
         return new Function(`return new WebSocket('${ url }');`)();
     }
-    throw new ReferenceError('Incorrect environment detected for BrowserWebSocket. Unable to create backing WebSocket for BrowserWebSocket.');
+    throw new ReferenceError('Unable to find global.WebSocket which is required for constructing a BrowserWebSocket.');
 };
 
 const createFileReader = function(): IBrowserFileReader {
-    if (isBrowser()) {
+    if (doesGlobalFileReaderExist()) {
         return new Function(`return new FileReader();`)();
     }
-    throw new ReferenceError('Incorrect environment detected for BrowserWebSocket. Unable to create backing FileReader for BrowserWebSocket.');
+    throw new ReferenceError('Unable to find global.FileReader. Unable to create FileReader for BrowserWebSocket.');
 };
 
 export class BrowserWebSocket implements ISocket {

diff --git a/libraries/botframework-streaming/src/webSocket/webSocketClient.ts b/libraries/botframework-streaming/src/webSocket/webSocketClient.ts
@@ -16,7 +16,7 @@ import {
 } from '../payloadTransport';
 import { BrowserWebSocket } from './browserWebSocket';
 import { NodeWebSocket } from './nodeWebSocket';
-import { isBrowser } from '../utilities';
+import { doesGlobalWebSocketExist } from '../utilities';
 import { WebSocketTransport } from './webSocketTransport';
 import { IStreamingTransportClient, IReceiveResponse } from '../interfaces';
 
@@ -60,7 +60,7 @@ export class WebSocketClient implements IStreamingTransportClient {
      * @returns A promise that will not resolve until the client stops listening for incoming messages.
      */
     public async connect(): Promise<void> {
-        if (isBrowser()) {
+        if (doesGlobalWebSocketExist()) {
             const ws = new BrowserWebSocket();
             await ws.connect(this._url);
             const transport = new WebSocketTransport(ws);

diff --git a/libraries/botframework-streaming/tests/InternalUtilities.test.js b/libraries/botframework-streaming/tests/InternalUtilities.test.js
@@ -1,10 +1,45 @@
-const { isBrowser } = require('../lib/utilities');
+const { doesGlobalFileReaderExist, doesGlobalWebSocketExist } = require('../lib/utilities');
 const chai = require('chai');
 const expect = chai.expect;
 
 describe('Internal Utilities', () => {
-    it('isBrowser() should return false when being run via Node.js', () => {
-        // More specifically, it should return false when the global object is not window.
-        expect(isBrowser()).to.be.false;
+    it('doesGlobalWebSocketExist() should return true if global.WebSocket is truthy', () => {
+        global.WebSocket = {};
+        try {
+            expect(doesGlobalWebSocketExist()).to.be.true;
+        } finally {
+            global.WebSocket = undefined;
+        }
+    });
+
+    it('doesGlobalWebSocketExist() should return false if global.WebSocket is null or undefined', () => {
+        expect(doesGlobalWebSocketExist()).to.be.false;
+
+        global.WebSocket = null;
+        try {
+            expect(doesGlobalWebSocketExist()).to.be.false;
+        } finally {
+            global.WebSocket = undefined;
+        }
+    });
+
+    it('doesGlobalFileReaderExist() should return true if global.FileReader is truthy', () => {
+        global.FileReader = {};
+        try {
+            expect(doesGlobalFileReaderExist()).to.be.true;
+        } finally {
+            global.FileReader = undefined;
+        }
+    });
+
+    it('doesGlobalFileReaderExist() should return false if global.FileReader is null or undefined', () => {
+        expect(doesGlobalFileReaderExist()).to.be.false;
+
+        global.FileReader = null;
+        try {
+            expect(doesGlobalFileReaderExist()).to.be.false;
+        } finally {
+            global.FileReader = undefined;
+        }
     });
 });