From 3444310bb25d7c6349eda33243aea8554bd007f2 Mon Sep 17 00:00:00 2001
From: Amplifier <240397093+microsoft-amplifier@users.noreply.github.com>
Date: Tue, 31 Mar 2026 03:27:30 -0700
Subject: [PATCH] feat: accept sourceUrl parameter in connectWebSocket for
 remote sessions (task-6)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

🤖 Generated with Amplifier
---
 muxplex/frontend/terminal.js             | 20 +++++--
 muxplex/frontend/tests/test_terminal.mjs | 74 ++++++++++++++++++++++++
 2 files changed, 89 insertions(+), 5 deletions(-)

diff --git a/muxplex/frontend/terminal.js b/muxplex/frontend/terminal.js
index 78d2159..b07a91f 100644
--- a/muxplex/frontend/terminal.js
+++ b/muxplex/frontend/terminal.js
@@ -11,9 +11,16 @@ let _vpHandler = null;
 
 // ─── Forward declarations ─────────────────────────────────────────────────────
 
-function connectWebSocket(name) {
-  const proto = location.protocol === 'https:' ? 'wss:' : 'ws:';
-  const url = `${proto}//${location.host}/terminal/ws`;
+function connectWebSocket(name, sourceUrl) {
+  var url;
+  if (sourceUrl) {
+    // Remote session: derive WS URL from the source's HTTP URL
+    url = sourceUrl.replace(/^http/, 'ws').replace(/\/+$/, '') + '/terminal/ws';
+  } else {
+    // Local session: same origin
+    var proto = location.protocol === 'https:' ? 'wss:' : 'ws:';
+    url = proto + '//' + location.host + '/terminal/ws';
+  }
   const reconnectOverlay = document.getElementById('reconnect-overlay');
   const encoder = typeof TextEncoder !== 'undefined' ? new TextEncoder() : null;
 
@@ -175,8 +182,11 @@ function createTerminal() {
 /**
  * Open a terminal session inside #terminal-container.
  * @param {string} sessionName
+ * @param {string} [sourceUrl]  Optional HTTP URL of the remote muxplex instance.
+ *   When provided, the WebSocket connects to that remote host instead of the
+ *   current page origin.
  */
-function openTerminal(sessionName) {
+function openTerminal(sessionName, sourceUrl) {
   // Null _currentSession first so any in-flight close handler on the old WS won't
   // schedule a reconnect (it checks `if (!_currentSession) return;`).
   _currentSession = null;
@@ -222,7 +232,7 @@ function openTerminal(sessionName) {
     });
   }
 
-  connectWebSocket(sessionName);
+  connectWebSocket(sessionName, sourceUrl);
   initVisualViewport(); /* defined in Task 14 */
 }
 
diff --git a/muxplex/frontend/tests/test_terminal.mjs b/muxplex/frontend/tests/test_terminal.mjs
index d467737..0e96a3e 100644
--- a/muxplex/frontend/tests/test_terminal.mjs
+++ b/muxplex/frontend/tests/test_terminal.mjs
@@ -719,6 +719,80 @@ test('terminal is auto-focused when WebSocket opens', () => {
     '_term.focus() should be called exactly once when the WebSocket open event fires');
 });
 
+// --- sourceUrl / remote WebSocket tests ------------------------------------
+
+test('connectWebSocket uses remote origin when sourceUrl is provided', () => {
+  const t = loadTerminal();
+
+  const orig = globalThis.setTimeout;
+  globalThis.setTimeout = (_fn, _ms) => 0;
+
+  t.openTerminal('remote-session', 'http://work:8088');
+
+  globalThis.setTimeout = orig;
+
+  assert.ok(t.capturedWsUrl, 'WebSocket URL should have been captured');
+  assert.ok(
+    t.capturedWsUrl.startsWith('ws://work:8088/'),
+    `WebSocket URL should start with ws://work:8088/, got: ${t.capturedWsUrl}`,
+  );
+  assert.ok(
+    t.capturedWsUrl.endsWith('/terminal/ws'),
+    `WebSocket URL should end with /terminal/ws, got: ${t.capturedWsUrl}`,
+  );
+});
+
+test('connectWebSocket uses local origin when sourceUrl is empty string', () => {
+  const t = loadTerminal();
+
+  const orig = globalThis.setTimeout;
+  globalThis.setTimeout = (_fn, _ms) => 0;
+
+  t.openTerminal('local-session', '');
+
+  globalThis.setTimeout = orig;
+
+  assert.ok(t.capturedWsUrl, 'WebSocket URL should have been captured');
+  assert.ok(
+    t.capturedWsUrl.includes('localhost'),
+    `WebSocket URL should include localhost for empty sourceUrl, got: ${t.capturedWsUrl}`,
+  );
+});
+
+test('connectWebSocket uses local origin when sourceUrl is undefined', () => {
+  const t = loadTerminal();
+
+  const orig = globalThis.setTimeout;
+  globalThis.setTimeout = (_fn, _ms) => 0;
+
+  t.openTerminal('local-session');
+
+  globalThis.setTimeout = orig;
+
+  assert.ok(t.capturedWsUrl, 'WebSocket URL should have been captured');
+  assert.ok(
+    t.capturedWsUrl.includes('localhost'),
+    `WebSocket URL should include localhost when sourceUrl is undefined, got: ${t.capturedWsUrl}`,
+  );
+});
+
+test('connectWebSocket converts https sourceUrl to wss protocol', () => {
+  const t = loadTerminal();
+
+  const orig = globalThis.setTimeout;
+  globalThis.setTimeout = (_fn, _ms) => 0;
+
+  t.openTerminal('secure-session', 'https://devserver:8088');
+
+  globalThis.setTimeout = orig;
+
+  assert.ok(t.capturedWsUrl, 'WebSocket URL should have been captured');
+  assert.ok(
+    t.capturedWsUrl.startsWith('wss://devserver:8088/'),
+    `WebSocket URL should start with wss://devserver:8088/, got: ${t.capturedWsUrl}`,
+  );
+});
+
 // --- Android touch scroll ---------------------------------------------------
 
 test('terminal.js Android touch scroll is UA-gated', () => {