test(ws): add unhandled exceptions test (#2656)

Author: kettanaito

test/node/ws-api/ws.unhandled-exception.test.ts

@@ -0,0 +1,53 @@
+// @vitest-environment node-websocket
+import { ws } from 'msw'
+import { setupServer } from 'msw/node'
+
+const server = setupServer()
+const service = ws.link('ws://*')
+
+beforeAll(() => {
+  server.listen()
+  vi.spyOn(console, 'error').mockImplementation(() => void 0)
+})
+
+afterEach(() => {
+  server.resetHandlers()
+  vi.clearAllMocks()
+})
+
+afterAll(() => {
+  server.close()
+  vi.restoreAllMocks()
+})
+
+it('dispatches a WebSocket error event on handler exception', async () => {
+  server.use(
+    service.addEventListener('connection', () => {
+      throw new Error('Handler exception')
+    }),
+  )
+
+  const socket = new WebSocket('ws://localhost:3000')
+
+  const closeListener = vi.fn()
+  const errorListener = vi.fn()
+  socket.onclose = closeListener
+  socket.onerror = errorListener
+  socket.onopen = () => {
+    expect.fail('Must not open the WebSocket connection')
+  }
+
+  await expect.poll(() => errorListener).toHaveBeenCalledOnce()
+  expect(closeListener).toHaveBeenCalledOnce()
+  expect(closeListener).toHaveBeenCalledWith(
+    expect.objectContaining({
+      code: 1011,
+      reason: 'Handler exception',
+    }),
+  )
+  expect(socket.readyState).toBe(WebSocket.CLOSED)
+
+  expect(console.error, 'Prints the error for the user').toHaveBeenCalledWith(
+    new Error('Handler exception'),
+  )
+})