Use electron's DNS resolver, prioritizing ipv4 connections

ts/util/createHTTPSAgent.ts

@@ -0,0 +1,51 @@
+// Copyright 2013 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { Agent } from 'https';
+import type { AgentOptions } from 'https';
+
+import { SECOND } from './durations';
+import { electronLookup } from './dns';
+
+// Due to the Node.js bug, we must manually re-apply `servername` when creating
+// an outgoing TLS connection with "Happy Eyeballs" (`autoSelectFamily: true`).
+//
+// See: https://github.com/nodejs/node/pull/48255
+export function createHTTPSAgent(options: AgentOptions = {}): Agent {
+  type TLSSocketInternals = {
+    _init: (...args: Array<unknown>) => unknown;
+    setServername: (servername: string) => void;
+  };
+
+  const agent = new Agent({
+    ...options,
+    lookup: electronLookup,
+    autoSelectFamily: true,
+    autoSelectFamilyAttemptTimeout: 2 * SECOND,
+  });
+
+  const typedAgent = agent as unknown as {
+    createConnection: (
+      connectionOptions: { servername?: string },
+      callback: () => unknown
+    ) => TLSSocketInternals;
+  };
+
+  const oldCreateConnection = typedAgent.createConnection;
+  typedAgent.createConnection = function createConnection(
+    connectionOptions,
+    callback
+  ) {
+    const socket = oldCreateConnection.call(this, connectionOptions, callback);
+    const oldInit = socket._init;
+    socket._init = function _init(...args) {
+      const result = oldInit.apply(this, args);
+      if (connectionOptions.servername) {
+        socket.setServername(connectionOptions.servername);
+      }
+      return result;
+    };
+    return socket;
+  };
+  return agent;
+}