Use Electron fetch to get Proxy settings properly (#229202)

* Attempt to use Electron fetch

* Remove Content-Length header because electron doesn't like it

"Apparently Chromium doesn’t want the caller to set content-length, but will set it itself."

extensions/microsoft-authentication/extension-browser.webpack.config.js

@@ -24,6 +24,7 @@ module.exports = withBrowserDefaults({
 		alias: {
 			'./node/authServer': path.resolve(__dirname, 'src/browser/authServer'),
 			'./node/buffer': path.resolve(__dirname, 'src/browser/buffer'),
+			'./node/fetch': path.resolve(__dirname, 'src/browser/fetch'),
 			'./node/authProvider': path.resolve(__dirname, 'src/browser/authProvider'),
 		}
 	}

extensions/microsoft-authentication/src/AADHelper.ts

@@ -11,6 +11,7 @@ import { generateCodeChallenge, generateCodeVerifier, randomUUID } from './crypt
 import { BetterTokenStorage, IDidChangeInOtherWindowEvent } from './betterSecretStorage';
 import { LoopbackAuthServer } from './node/authServer';
 import { base64Decode } from './node/buffer';
+import fetch from './node/fetch';
 import { UriEventHandler } from './UriEventHandler';
 import TelemetryReporter from '@vscode/extension-telemetry';
 import { Environment } from '@azure/ms-rest-azure-env';
@@ -805,11 +806,10 @@ export class AzureActiveDirectoryService {
 			let result;
 			let errorMessage: string | undefined;
 			try {
-				result = await fetch(endpoint, {
+				result = await fetch(endpoint.toString(), {
 					method: 'POST',
 					headers: {
-						'Content-Type': 'application/x-www-form-urlencoded',
-						'Content-Length': postData.length.toString()
+						'Content-Type': 'application/x-www-form-urlencoded'
 					},
 					body: postData
 				});

extensions/microsoft-authentication/src/browser/fetch.ts

@@ -0,0 +1,6 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+export default fetch;

extensions/microsoft-authentication/src/node/fetch.ts

@@ -0,0 +1,12 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+let _fetch: typeof fetch;
+try {
+	_fetch = require('electron').net.fetch;
+} catch {
+	_fetch = fetch;
+}
+export default _fetch;