From 09c554b446597102ee7798ca87d8cc6c65e72b4d Mon Sep 17 00:00:00 2001
From: Zhicheng Han <43314240+hanzckernel@users.noreply.github.com>
Date: Fri, 15 May 2026 12:43:57 +0200
Subject: [PATCH] test: cover chat streaming browser contract (#766)

---
 tests/e2e/chat-streaming.spec.ts | 63 ++++++++++++++++++++++++++++++++
 tests/e2e/fixtures.ts            | 59 ++++++++++++++++++++++++++++++
 2 files changed, 122 insertions(+)
 create mode 100644 tests/e2e/chat-streaming.spec.ts

diff --git a/tests/e2e/chat-streaming.spec.ts b/tests/e2e/chat-streaming.spec.ts
new file mode 100644
index 0000000..9813632
--- /dev/null
+++ b/tests/e2e/chat-streaming.spec.ts
@@ -0,0 +1,63 @@
+import { expect, test } from '@playwright/test'
+import { authenticate, mockChatSocket, mockHermesApi, TEST_ACCESS_KEY } from './fixtures'
+
+test('sends a chat run and renders streamed Socket.IO response events', async ({ page }) => {
+  await authenticate(page, TEST_ACCESS_KEY, 'research')
+  const api = await mockHermesApi(page)
+  await mockChatSocket(page)
+
+  await page.goto('/#/hermes/chat')
+
+  const input = page.getByPlaceholder('Type a message... (Enter to send, Shift+Enter for new line)')
+  await expect(input).toBeVisible()
+  await input.fill('Summarize the queue')
+  await page.getByRole('button', { name: 'Send' }).click()
+
+  await expect(page.locator('p').filter({ hasText: /^Summarize the queue$/ })).toBeVisible()
+
+  const socketState = await page.waitForFunction(() => {
+    const state = (window as any).__PW_CHAT_SOCKET__
+    return state?.emitted?.some((item: any) => item.event === 'run')
+      ? {
+          socket: {
+            url: state.latest.url,
+            options: state.latest.options,
+          },
+          emitted: state.emitted,
+        }
+      : null
+  })
+  const { socket, emitted } = await socketState.jsonValue() as any
+  const run = emitted.find((item: any) => item.event === 'run')
+
+  expect(socket.url).toBe('/chat-run')
+  expect(socket.options.auth).toEqual({ token: TEST_ACCESS_KEY })
+  expect(socket.options.query).toEqual({ profile: 'research' })
+  expect(run.payload).toMatchObject({
+    input: 'Summarize the queue',
+    queue_id: expect.any(String),
+    session_id: expect.any(String),
+    source: 'api_server',
+  })
+  expect(run.payload.model).toBe('test-model')
+
+  const sessionId = run.payload.session_id
+  await page.evaluate((sid) => {
+    const socket = (window as any).__PW_CHAT_SOCKET__.latest
+    socket.__trigger('run.started', { event: 'run.started', session_id: sid, run_id: 'run-1' })
+    socket.__trigger('message.delta', { event: 'message.delta', session_id: sid, run_id: 'run-1', delta: 'Streaming ' })
+    socket.__trigger('message.delta', { event: 'message.delta', session_id: sid, run_id: 'run-1', delta: 'answer from Hermes' })
+    socket.__trigger('run.completed', {
+      event: 'run.completed',
+      session_id: sid,
+      run_id: 'run-1',
+      output: 'Streaming answer from Hermes',
+      inputTokens: 11,
+      outputTokens: 7,
+    })
+  }, sessionId)
+
+  await expect(page.getByText('Streaming answer from Hermes')).toBeVisible()
+  await expect(page.getByRole('button', { name: 'Send' })).toBeVisible()
+  expect(api.unexpectedRequests).toEqual([])
+})
diff --git a/tests/e2e/fixtures.ts b/tests/e2e/fixtures.ts
index 4ec776f..2310f8a 100644
--- a/tests/e2e/fixtures.ts
+++ b/tests/e2e/fixtures.ts
@@ -189,3 +189,62 @@ export async function authenticate(page: Page, accessKey = TEST_ACCESS_KEY, prof
     }
   }, { storedToken: accessKey, storedProfileName: profileName })
 }
+
+export async function mockChatSocket(page: Page) {
+  await page.route('**/node_modules/.vite/deps/socket__io-client.js*', async (route) => {
+    await route.fulfill({
+      status: 200,
+      contentType: 'application/javascript',
+      body: `
+const state = window.__PW_CHAT_SOCKET__ || (window.__PW_CHAT_SOCKET__ = { sockets: [], emitted: [] })
+function makeSocket(url, options) {
+  const listeners = new Map()
+  const onceListeners = new Map()
+  const socket = {
+    connected: true,
+    url,
+    options,
+    on(event, handler) {
+      const handlers = listeners.get(event) || []
+      handlers.push(handler)
+      listeners.set(event, handlers)
+      return this
+    },
+    once(event, handler) {
+      const handlers = onceListeners.get(event) || []
+      handlers.push(handler)
+      onceListeners.set(event, handlers)
+      return this
+    },
+    emit(event, payload) {
+      state.emitted.push({ event, payload })
+      return this
+    },
+    removeAllListeners() {
+      listeners.clear()
+      onceListeners.clear()
+      return this
+    },
+    disconnect() {
+      this.connected = false
+      return this
+    },
+    __trigger(event, payload) {
+      for (const handler of listeners.get(event) || []) handler(payload)
+      const handlers = onceListeners.get(event) || []
+      onceListeners.delete(event)
+      for (const handler of handlers) handler(payload)
+    },
+  }
+  state.sockets.push(socket)
+  state.latest = socket
+  return socket
+}
+export function io(url, options) {
+  return makeSocket(url, options)
+}
+export default { io }
+`,
+    })
+  })
+}