test: set up playwright with msw

frontend/mockServiceWorker.js

@@ -0,0 +1,287 @@
+/* eslint-disable */
+/* tslint:disable */
+
+/**
+ * Mock Service Worker (2.2.0).
+ * @see https://github.com/mswjs/msw
+ * - Please do NOT modify this file.
+ * - Please do NOT serve this file on production.
+ */
+
+const INTEGRITY_CHECKSUM = '223d191a56023cd36aa88c802961b911'
+const IS_MOCKED_RESPONSE = Symbol('isMockedResponse')
+const activeClientIds = new Set()
+
+self.addEventListener('install', function () {
+  self.skipWaiting()
+})
+
+self.addEventListener('activate', function (event) {
+  event.waitUntil(self.clients.claim())
+})
+
+self.addEventListener('message', async function (event) {
+  const clientId = event.source.id
+
+  if (!clientId || !self.clients) {
+    return
+  }
+
+  const client = await self.clients.get(clientId)
+
+  if (!client) {
+    return
+  }
+
+  const allClients = await self.clients.matchAll({
+    type: 'window',
+  })
+
+  switch (event.data) {
+    case 'KEEPALIVE_REQUEST': {
+      sendToClient(client, {
+        type: 'KEEPALIVE_RESPONSE',
+      })
+      break
+    }
+
+    case 'INTEGRITY_CHECK_REQUEST': {
+      sendToClient(client, {
+        type: 'INTEGRITY_CHECK_RESPONSE',
+        payload: INTEGRITY_CHECKSUM,
+      })
+      break
+    }
+
+    case 'MOCK_ACTIVATE': {
+      activeClientIds.add(clientId)
+
+      sendToClient(client, {
+        type: 'MOCKING_ENABLED',
+        payload: true,
+      })
+      break
+    }
+
+    case 'MOCK_DEACTIVATE': {
+      activeClientIds.delete(clientId)
+      break
+    }
+
+    case 'CLIENT_CLOSED': {
+      activeClientIds.delete(clientId)
+
+      const remainingClients = allClients.filter((client) => {
+        return client.id !== clientId
+      })
+
+      // Unregister itself when there are no more clients
+      if (remainingClients.length === 0) {
+        self.registration.unregister()
+      }
+
+      break
+    }
+  }
+})
+
+self.addEventListener('fetch', function (event) {
+  const { request } = event
+
+  // Bypass navigation requests.
+  if (request.mode === 'navigate') {
+    return
+  }
+
+  // Opening the DevTools triggers the "only-if-cached" request
+  // that cannot be handled by the worker. Bypass such requests.
+  if (request.cache === 'only-if-cached' && request.mode !== 'same-origin') {
+    return
+  }
+
+  // Bypass all requests when there are no active clients.
+  // Prevents the self-unregistered worked from handling requests
+  // after it's been deleted (still remains active until the next reload).
+  if (activeClientIds.size === 0) {
+    return
+  }
+
+  // Generate unique request ID.
+  const requestId = crypto.randomUUID()
+  event.respondWith(handleRequest(event, requestId))
+})
+
+async function handleRequest(event, requestId) {
+  const client = await resolveMainClient(event)
+  const response = await getResponse(event, client, requestId)
+
+  // Send back the response clone for the "response:*" life-cycle events.
+  // Ensure MSW is active and ready to handle the message, otherwise
+  // this message will pend indefinitely.
+  if (client && activeClientIds.has(client.id)) {
+    ;(async function () {
+      const responseClone = response.clone()
+
+      sendToClient(
+        client,
+        {
+          type: 'RESPONSE',
+          payload: {
+            requestId,
+            isMockedResponse: IS_MOCKED_RESPONSE in response,
+            type: responseClone.type,
+            status: responseClone.status,
+            statusText: responseClone.statusText,
+            body: responseClone.body,
+            headers: Object.fromEntries(responseClone.headers.entries()),
+          },
+        },
+        [responseClone.body],
+      )
+    })()
+  }
+
+  return response
+}
+
+// Resolve the main client for the given event.
+// Client that issues a request doesn't necessarily equal the client
+// that registered the worker. It's with the latter the worker should
+// communicate with during the response resolving phase.
+async function resolveMainClient(event) {
+  const client = await self.clients.get(event.clientId)
+
+  if (client?.frameType === 'top-level') {
+    return client
+  }
+
+  const allClients = await self.clients.matchAll({
+    type: 'window',
+  })
+
+  return allClients
+    .filter((client) => {
+      // Get only those clients that are currently visible.
+      return client.visibilityState === 'visible'
+    })
+    .find((client) => {
+      // Find the client ID that's recorded in the
+      // set of clients that have registered the worker.
+      return activeClientIds.has(client.id)
+    })
+}
+
+async function getResponse(event, client, requestId) {
+  const { request } = event
+
+  // Clone the request because it might've been already used
+  // (i.e. its body has been read and sent to the client).
+  const requestClone = request.clone()
+
+  function passthrough() {
+    const headers = Object.fromEntries(requestClone.headers.entries())
+
+    // Remove internal MSW request header so the passthrough request
+    // complies with any potential CORS preflight checks on the server.
+    // Some servers forbid unknown request headers.
+    delete headers['x-msw-intention']
+
+    return fetch(requestClone, { headers })
+  }
+
+  // Bypass mocking when the client is not active.
+  if (!client) {
+    return passthrough()
+  }
+
+  // Bypass initial page load requests (i.e. static assets).
+  // The absence of the immediate/parent client in the map of the active clients
+  // means that MSW hasn't dispatched the "MOCK_ACTIVATE" event yet
+  // and is not ready to handle requests.
+  if (!activeClientIds.has(client.id)) {
+    return passthrough()
+  }
+
+  // Bypass requests with the explicit bypass header.
+  // Such requests can be issued by "ctx.fetch()".
+  const mswIntention = request.headers.get('x-msw-intention')
+  if (['bypass', 'passthrough'].includes(mswIntention)) {
+    return passthrough()
+  }
+
+  // Notify the client that a request has been intercepted.
+  const requestBuffer = await request.arrayBuffer()
+  const clientMessage = await sendToClient(
+    client,
+    {
+      type: 'REQUEST',
+      payload: {
+        id: requestId,
+        url: request.url,
+        mode: request.mode,
+        method: request.method,
+        headers: Object.fromEntries(request.headers.entries()),
+        cache: request.cache,
+        credentials: request.credentials,
+        destination: request.destination,
+        integrity: request.integrity,
+        redirect: request.redirect,
+        referrer: request.referrer,
+        referrerPolicy: request.referrerPolicy,
+        body: requestBuffer,
+        keepalive: request.keepalive,
+      },
+    },
+    [requestBuffer],
+  )
+
+  switch (clientMessage.type) {
+    case 'MOCK_RESPONSE': {
+      return respondWithMock(clientMessage.data)
+    }
+
+    case 'MOCK_NOT_FOUND': {
+      return passthrough()
+    }
+  }
+
+  return passthrough()
+}
+
+function sendToClient(client, message, transferrables = []) {
+  return new Promise((resolve, reject) => {
+    const channel = new MessageChannel()
+
+    channel.port1.onmessage = (event) => {
+      if (event.data && event.data.error) {
+        return reject(event.data.error)
+      }
+
+      resolve(event.data)
+    }
+
+    client.postMessage(
+      message,
+      [channel.port2].concat(transferrables.filter(Boolean)),
+    )
+  })
+}
+
+async function respondWithMock(response) {
+  // Setting response status code to 0 is a no-op.
+  // However, when responding with a "Response.error()", the produced Response
+  // instance will have status code set to 0. Since it's not possible to create
+  // a Response instance with status code 0, handle that use-case separately.
+  if (response.status === 0) {
+    return Response.error()
+  }
+
+  const mockedResponse = new Response(response.body, response)
+
+  Reflect.defineProperty(mockedResponse, IS_MOCKED_RESPONSE, {
+    value: true,
+    enumerable: true,
+  })
+
+  return mockedResponse
+}

frontend/playwright.config.ts

@@ -1,5 +1,4 @@
 import { defineConfig, devices } from '@playwright/test';
-
 /**
  * Read environment variables from file.
  * https://github.com/motdotla/dotenv
@@ -24,7 +23,7 @@ export default defineConfig({
   /* Shared settings for all the projects below. See https://playwright.dev/docs/api/class-testoptions. */
   use: {
     /* Base URL to use in actions like `await page.goto('/')`. */
-    // baseURL: 'http://127.0.0.1:3000',
+    baseURL: 'http://localhost:49768/',
 
     /* Collect trace when retrying the failed test. See https://playwright.dev/docs/trace-viewer */
     trace: 'on-first-retry',
@@ -69,9 +68,9 @@ export default defineConfig({
   ],
 
   /* Run your local dev server before starting the tests */
-  // webServer: {
-  //   command: 'npm run start',
-  //   url: 'http://127.0.0.1:3000',
-  //   reuseExistingServer: !process.env.CI,
-  // },
+  webServer: {
+    command: 'pnpm exec vite --host localhost --port 49768 --strictPort --clearScreen false',
+    url: 'http://localhost:49768/',
+    reuseExistingServer: !process.env.CI,
+  },
 });

frontend/src/main.tsx

@@ -39,12 +39,25 @@ const router = createBrowserRouter([
 ])
 const queryClient = new QueryClient()
 
-createRoot(document.getElementById("root")!).render(
-  <StrictMode>
-    <QueryClientProvider client={queryClient}>
-      <GlobalStyles />
-      <RouterProvider router={router} />
-      <ReactQueryDevtools initialIsOpen={false} />
-    </QueryClientProvider>
-  </StrictMode>,
-)
+// Enable mocking in development using msw server set up for the browser
+async function enableMocking() {
+  if (process.env.NODE_ENV !== "development") {
+    return
+  }
+
+  const { worker } = await import("./tests/mocks/browser")
+
+  return worker.start()
+}
+
+enableMocking().then(() => {
+  createRoot(document.getElementById("root")!).render(
+    <StrictMode>
+      <QueryClientProvider client={queryClient}>
+        <GlobalStyles />
+        <RouterProvider router={router} />
+        <ReactQueryDevtools initialIsOpen={false} />
+      </QueryClientProvider>
+    </StrictMode>,
+  )
+})

frontend/src/tests/mocks/browser.ts

@@ -0,0 +1,4 @@
+import { setupWorker } from "msw/browser"
+import { handlers } from "./handlers"
+
+export const worker = setupWorker(...handlers)

frontend/vitest.setup.ts

@@ -3,14 +3,15 @@ import { server } from "./src/tests/mocks/node"
 global.ResizeObserver = require("resize-observer-polyfill");
 global.requestAnimationFrame = fn => window.setTimeout(fn, 0);
 import { beforeAll, afterEach, afterAll } from 'vitest'
+
 beforeAll(() => {
     server.listen()
   })
 
-  afterEach(() => {
+afterEach(() => {
     server.resetHandlers()
   })
 
-  afterAll(() => {
+afterAll(() => {
     server.close()
   })