refactor(worker): simplify WebSocket URL resolution for terminal connections

- Replaced manual URL construction with a dedicated function to resolve WebSocket client URLs, improving code clarity and maintainability.
- Updated the test command in package.json to include additional test execution for shared components.

Made-with: Cursor

Author: acoyfellow

package.json

@@ -18,7 +18,7 @@
     "db:studio": "drizzle-kit studio",
     "db:local": "wrangler d1 migrations apply cloudshell-db --local",
     "db:remote": "wrangler d1 migrations apply cloudshell-db --remote",
-    "test": "vitest run",
+    "test": "vitest run && bun test shared/",
     "test:watch": "vitest"
   },
   "devDependencies": {

shared/resolve-terminal-ws-url.test.ts

@@ -0,0 +1,32 @@
+import { describe, expect, it } from 'bun:test';
+import { resolveTerminalWebSocketClientUrl } from './resolve-terminal-ws-url';
+
+describe('resolveTerminalWebSocketClientUrl', () => {
+  it('prod: same-origin WSS on app host, proxy mode (not API subdomain)', () => {
+    const apiOrigin = 'https://cloudshell-api.example.com';
+    const { url, mode } = resolveTerminalWebSocketClientUrl({
+      dev: false,
+      appOrigin: 'https://cloudshell.example.com',
+      workerDevOrigin: 'unused',
+      ticket: 'a.b',
+    });
+
+    expect(mode).toBe('proxy');
+    expect(url.startsWith('wss://cloudshell.example.com/ws/terminal?')).toBe(true);
+    expect(url).toContain('ticket=a.b');
+    expect(url).not.toContain(apiOrigin);
+    expect(url).not.toContain('cloudshell-api');
+  });
+
+  it('dev: WS URL targets worker dev origin, direct mode', () => {
+    const { url, mode } = resolveTerminalWebSocketClientUrl({
+      dev: true,
+      appOrigin: 'https://unused',
+      workerDevOrigin: 'http://localhost:1338',
+      ticket: 't',
+    });
+
+    expect(mode).toBe('direct');
+    expect(url).toBe('ws://localhost:1338/ws/terminal?ticket=t');
+  });
+});

shared/resolve-terminal-ws-url.ts

@@ -0,0 +1,20 @@
+/** Pure URL builder for the browser terminal WebSocket (no Svelte / Workers imports). */
+
+export function resolveTerminalWebSocketClientUrl(input: {
+  readonly dev: boolean;
+  readonly appOrigin: string;
+  readonly workerDevOrigin: string;
+  readonly ticket: string;
+}): { readonly url: string; readonly mode: 'proxy' | 'direct' } {
+  if (input.dev) {
+    const url = new URL('/ws/terminal', input.workerDevOrigin);
+    url.protocol = url.protocol === 'https:' ? 'wss:' : 'ws:';
+    url.searchParams.set('ticket', input.ticket);
+    return { url: url.toString(), mode: 'direct' };
+  }
+
+  const url = new URL('/ws/terminal', input.appOrigin);
+  url.protocol = url.protocol === 'https:' ? 'wss:' : 'ws:';
+  url.searchParams.set('ticket', input.ticket);
+  return { url: url.toString(), mode: 'proxy' };
+}

src/lib/server/worker.ts

@@ -1,5 +1,6 @@
 import { dev } from '$app/environment';
 import { error, type RequestEvent } from '@sveltejs/kit';
+import { resolveTerminalWebSocketClientUrl } from '../../../shared/resolve-terminal-ws-url';
 import { createTerminalTicket } from '../../../shared/terminal-ticket';
 
 const DEFAULT_DEV_WORKER_ORIGIN = 'http://localhost:1338';
@@ -119,17 +120,10 @@ export async function resolveTerminalConnection(
     secret
   );
 
-  if (dev) {
-    const url = new URL('/ws/terminal', getWorkerOrigin(event));
-    url.protocol = url.protocol === 'https:' ? 'wss:' : 'ws:';
-    url.searchParams.set('ticket', ticket);
-    return { url: url.toString(), mode: 'direct' };
-  }
-
-  // Same-origin WSS: browser → Pages `/ws/terminal` → `WORKER.fetch` → API worker (`proxyTerminalWebSocket`).
-  // Avoids cross-host upgrades (app vs api) which often surface as 1006 with little detail.
-  const url = new URL('/ws/terminal', event.url.origin);
-  url.protocol = url.protocol === 'https:' ? 'wss:' : 'ws:';
-  url.searchParams.set('ticket', ticket);
-  return { url: url.toString(), mode: 'proxy' };
+  return resolveTerminalWebSocketClientUrl({
+    dev,
+    appOrigin: event.url.origin,
+    workerDevOrigin: getWorkerOrigin(event),
+    ticket,
+  });
 }