Index: frontend/node_modules/agent-base/src/index.ts
===================================================================
--- frontend/node_modules/agent-base/src/index.ts	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/agent-base/src/index.ts	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,345 @@
+import net from 'net';
+import http from 'http';
+import https from 'https';
+import { Duplex } from 'stream';
+import { EventEmitter } from 'events';
+import createDebug from 'debug';
+import promisify from './promisify';
+
+const debug = createDebug('agent-base');
+
+function isAgent(v: any): v is createAgent.AgentLike {
+	return Boolean(v) && typeof v.addRequest === 'function';
+}
+
+function isSecureEndpoint(): boolean {
+	const { stack } = new Error();
+	if (typeof stack !== 'string') return false;
+	return stack.split('\n').some(l => l.indexOf('(https.js:') !== -1  || l.indexOf('node:https:') !== -1);
+}
+
+function createAgent(opts?: createAgent.AgentOptions): createAgent.Agent;
+function createAgent(
+	callback: createAgent.AgentCallback,
+	opts?: createAgent.AgentOptions
+): createAgent.Agent;
+function createAgent(
+	callback?: createAgent.AgentCallback | createAgent.AgentOptions,
+	opts?: createAgent.AgentOptions
+) {
+	return new createAgent.Agent(callback, opts);
+}
+
+namespace createAgent {
+	export interface ClientRequest extends http.ClientRequest {
+		_last?: boolean;
+		_hadError?: boolean;
+		method: string;
+	}
+
+	export interface AgentRequestOptions {
+		host?: string;
+		path?: string;
+		// `port` on `http.RequestOptions` can be a string or undefined,
+		// but `net.TcpNetConnectOpts` expects only a number
+		port: number;
+	}
+
+	export interface HttpRequestOptions
+		extends AgentRequestOptions,
+			Omit<http.RequestOptions, keyof AgentRequestOptions> {
+		secureEndpoint: false;
+	}
+
+	export interface HttpsRequestOptions
+		extends AgentRequestOptions,
+			Omit<https.RequestOptions, keyof AgentRequestOptions> {
+		secureEndpoint: true;
+	}
+
+	export type RequestOptions = HttpRequestOptions | HttpsRequestOptions;
+
+	export type AgentLike = Pick<createAgent.Agent, 'addRequest'> | http.Agent;
+
+	export type AgentCallbackReturn = Duplex | AgentLike;
+
+	export type AgentCallbackCallback = (
+		err?: Error | null,
+		socket?: createAgent.AgentCallbackReturn
+	) => void;
+
+	export type AgentCallbackPromise = (
+		req: createAgent.ClientRequest,
+		opts: createAgent.RequestOptions
+	) =>
+		| createAgent.AgentCallbackReturn
+		| Promise<createAgent.AgentCallbackReturn>;
+
+	export type AgentCallback = typeof Agent.prototype.callback;
+
+	export type AgentOptions = {
+		timeout?: number;
+	};
+
+	/**
+	 * Base `http.Agent` implementation.
+	 * No pooling/keep-alive is implemented by default.
+	 *
+	 * @param {Function} callback
+	 * @api public
+	 */
+	export class Agent extends EventEmitter {
+		public timeout: number | null;
+		public maxFreeSockets: number;
+		public maxTotalSockets: number;
+		public maxSockets: number;
+		public sockets: {
+			[key: string]: net.Socket[];
+		};
+		public freeSockets: {
+			[key: string]: net.Socket[];
+		};
+		public requests: {
+			[key: string]: http.IncomingMessage[];
+		};
+		public options: https.AgentOptions;
+		private promisifiedCallback?: createAgent.AgentCallbackPromise;
+		private explicitDefaultPort?: number;
+		private explicitProtocol?: string;
+
+		constructor(
+			callback?: createAgent.AgentCallback | createAgent.AgentOptions,
+			_opts?: createAgent.AgentOptions
+		) {
+			super();
+
+			let opts = _opts;
+			if (typeof callback === 'function') {
+				this.callback = callback;
+			} else if (callback) {
+				opts = callback;
+			}
+
+			// Timeout for the socket to be returned from the callback
+			this.timeout = null;
+			if (opts && typeof opts.timeout === 'number') {
+				this.timeout = opts.timeout;
+			}
+
+			// These aren't actually used by `agent-base`, but are required
+			// for the TypeScript definition files in `@types/node` :/
+			this.maxFreeSockets = 1;
+			this.maxSockets = 1;
+			this.maxTotalSockets = Infinity;
+			this.sockets = {};
+			this.freeSockets = {};
+			this.requests = {};
+			this.options = {};
+		}
+
+		get defaultPort(): number {
+			if (typeof this.explicitDefaultPort === 'number') {
+				return this.explicitDefaultPort;
+			}
+			return isSecureEndpoint() ? 443 : 80;
+		}
+
+		set defaultPort(v: number) {
+			this.explicitDefaultPort = v;
+		}
+
+		get protocol(): string {
+			if (typeof this.explicitProtocol === 'string') {
+				return this.explicitProtocol;
+			}
+			return isSecureEndpoint() ? 'https:' : 'http:';
+		}
+
+		set protocol(v: string) {
+			this.explicitProtocol = v;
+		}
+
+		callback(
+			req: createAgent.ClientRequest,
+			opts: createAgent.RequestOptions,
+			fn: createAgent.AgentCallbackCallback
+		): void;
+		callback(
+			req: createAgent.ClientRequest,
+			opts: createAgent.RequestOptions
+		):
+			| createAgent.AgentCallbackReturn
+			| Promise<createAgent.AgentCallbackReturn>;
+		callback(
+			req: createAgent.ClientRequest,
+			opts: createAgent.AgentOptions,
+			fn?: createAgent.AgentCallbackCallback
+		):
+			| createAgent.AgentCallbackReturn
+			| Promise<createAgent.AgentCallbackReturn>
+			| void {
+			throw new Error(
+				'"agent-base" has no default implementation, you must subclass and override `callback()`'
+			);
+		}
+
+		/**
+		 * Called by node-core's "_http_client.js" module when creating
+		 * a new HTTP request with this Agent instance.
+		 *
+		 * @api public
+		 */
+		addRequest(req: ClientRequest, _opts: RequestOptions): void {
+			const opts: RequestOptions = { ..._opts };
+
+			if (typeof opts.secureEndpoint !== 'boolean') {
+				opts.secureEndpoint = isSecureEndpoint();
+			}
+
+			if (opts.host == null) {
+				opts.host = 'localhost';
+			}
+
+			if (opts.port == null) {
+				opts.port = opts.secureEndpoint ? 443 : 80;
+			}
+
+			if (opts.protocol == null) {
+				opts.protocol = opts.secureEndpoint ? 'https:' : 'http:';
+			}
+
+			if (opts.host && opts.path) {
+				// If both a `host` and `path` are specified then it's most
+				// likely the result of a `url.parse()` call... we need to
+				// remove the `path` portion so that `net.connect()` doesn't
+				// attempt to open that as a unix socket file.
+				delete opts.path;
+			}
+
+			delete opts.agent;
+			delete opts.hostname;
+			delete opts._defaultAgent;
+			delete opts.defaultPort;
+			delete opts.createConnection;
+
+			// Hint to use "Connection: close"
+			// XXX: non-documented `http` module API :(
+			req._last = true;
+			req.shouldKeepAlive = false;
+
+			let timedOut = false;
+			let timeoutId: ReturnType<typeof setTimeout> | null = null;
+			const timeoutMs = opts.timeout || this.timeout;
+
+			const onerror = (err: NodeJS.ErrnoException) => {
+				if (req._hadError) return;
+				req.emit('error', err);
+				// For Safety. Some additional errors might fire later on
+				// and we need to make sure we don't double-fire the error event.
+				req._hadError = true;
+			};
+
+			const ontimeout = () => {
+				timeoutId = null;
+				timedOut = true;
+				const err: NodeJS.ErrnoException = new Error(
+					`A "socket" was not created for HTTP request before ${timeoutMs}ms`
+				);
+				err.code = 'ETIMEOUT';
+				onerror(err);
+			};
+
+			const callbackError = (err: NodeJS.ErrnoException) => {
+				if (timedOut) return;
+				if (timeoutId !== null) {
+					clearTimeout(timeoutId);
+					timeoutId = null;
+				}
+				onerror(err);
+			};
+
+			const onsocket = (socket: AgentCallbackReturn) => {
+				if (timedOut) return;
+				if (timeoutId != null) {
+					clearTimeout(timeoutId);
+					timeoutId = null;
+				}
+
+				if (isAgent(socket)) {
+					// `socket` is actually an `http.Agent` instance, so
+					// relinquish responsibility for this `req` to the Agent
+					// from here on
+					debug(
+						'Callback returned another Agent instance %o',
+						socket.constructor.name
+					);
+					(socket as createAgent.Agent).addRequest(req, opts);
+					return;
+				}
+
+				if (socket) {
+					socket.once('free', () => {
+						this.freeSocket(socket as net.Socket, opts);
+					});
+					req.onSocket(socket as net.Socket);
+					return;
+				}
+
+				const err = new Error(
+					`no Duplex stream was returned to agent-base for \`${req.method} ${req.path}\``
+				);
+				onerror(err);
+			};
+
+			if (typeof this.callback !== 'function') {
+				onerror(new Error('`callback` is not defined'));
+				return;
+			}
+
+			if (!this.promisifiedCallback) {
+				if (this.callback.length >= 3) {
+					debug('Converting legacy callback function to promise');
+					this.promisifiedCallback = promisify(this.callback);
+				} else {
+					this.promisifiedCallback = this.callback;
+				}
+			}
+
+			if (typeof timeoutMs === 'number' && timeoutMs > 0) {
+				timeoutId = setTimeout(ontimeout, timeoutMs);
+			}
+
+			if ('port' in opts && typeof opts.port !== 'number') {
+				opts.port = Number(opts.port);
+			}
+
+			try {
+				debug(
+					'Resolving socket for %o request: %o',
+					opts.protocol,
+					`${req.method} ${req.path}`
+				);
+				Promise.resolve(this.promisifiedCallback(req, opts)).then(
+					onsocket,
+					callbackError
+				);
+			} catch (err) {
+				Promise.reject(err).catch(callbackError);
+			}
+		}
+
+		freeSocket(socket: net.Socket, opts: AgentOptions) {
+			debug('Freeing socket %o %o', socket.constructor.name, opts);
+			socket.destroy();
+		}
+
+		destroy() {
+			debug('Destroying agent %o', this.constructor.name);
+		}
+	}
+
+	// So that `instanceof` works correctly
+	createAgent.prototype = createAgent.Agent.prototype;
+}
+
+export = createAgent;
Index: frontend/node_modules/agent-base/src/promisify.ts
===================================================================
--- frontend/node_modules/agent-base/src/promisify.ts	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/agent-base/src/promisify.ts	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,33 @@
+import {
+	Agent,
+	ClientRequest,
+	RequestOptions,
+	AgentCallbackCallback,
+	AgentCallbackPromise,
+	AgentCallbackReturn
+} from './index';
+
+type LegacyCallback = (
+	req: ClientRequest,
+	opts: RequestOptions,
+	fn: AgentCallbackCallback
+) => void;
+
+export default function promisify(fn: LegacyCallback): AgentCallbackPromise {
+	return function(this: Agent, req: ClientRequest, opts: RequestOptions) {
+		return new Promise((resolve, reject) => {
+			fn.call(
+				this,
+				req,
+				opts,
+				(err: Error | null | undefined, rtn?: AgentCallbackReturn) => {
+					if (err) {
+						reject(err);
+					} else {
+						resolve(rtn);
+					}
+				}
+			);
+		});
+	};
+}