Merge from vscode 8e0f348413f4f616c23a88ae30030efa85811973 (#6381)

* Merge from vscode 8e0f348413f4f616c23a88ae30030efa85811973

* disable strict null check

src/vs/platform/request/node/proxy.ts

@@ -0,0 +1,52 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { Url, parse as parseUrl } from 'url';
+import { isBoolean } from 'vs/base/common/types';
+
+export type Agent = any;
+
+function getSystemProxyURI(requestURL: Url): string | null {
+	if (requestURL.protocol === 'http:') {
+		return process.env.HTTP_PROXY || process.env.http_proxy || null;
+	} else if (requestURL.protocol === 'https:') {
+		return process.env.HTTPS_PROXY || process.env.https_proxy || process.env.HTTP_PROXY || process.env.http_proxy || null;
+	}
+
+	return null;
+}
+
+export interface IOptions {
+	proxyUrl?: string;
+	strictSSL?: boolean;
+}
+
+export async function getProxyAgent(rawRequestURL: string, options: IOptions = {}): Promise<Agent> {
+	const requestURL = parseUrl(rawRequestURL);
+	const proxyURL = options.proxyUrl || getSystemProxyURI(requestURL);
+
+	if (!proxyURL) {
+		return null;
+	}
+
+	const proxyEndpoint = parseUrl(proxyURL);
+
+	if (!/^https?:$/.test(proxyEndpoint.protocol || '')) {
+		return null;
+	}
+
+	const opts = {
+		host: proxyEndpoint.hostname || '',
+		port: Number(proxyEndpoint.port),
+		auth: proxyEndpoint.auth,
+		rejectUnauthorized: isBoolean(options.strictSSL) ? options.strictSSL : true
+	};
+
+	const Ctor = requestURL.protocol === 'http:'
+		? await import('http-proxy-agent')
+		: await import('https-proxy-agent');
+
+	return new Ctor(opts);
+}