fix(storybook): fix msw stories [EE-6503] (#10985)

.storybook/public/mockServiceWorker.js

@@ -2,22 +2,22 @@
 /* tslint:disable */
 
 /**
- * Mock Service Worker (0.36.3).
+ * Mock Service Worker (2.0.11).
  * @see https://github.com/mswjs/msw
  * - Please do NOT modify this file.
  * - Please do NOT serve this file on production.
  */
 
-const INTEGRITY_CHECKSUM = '02f4ad4a2797f85668baf196e553d929';
-const bypassHeaderName = 'x-msw-bypass';
+const INTEGRITY_CHECKSUM = 'c5f7f8e188b673ea4e677df7ea3c5a39';
+const IS_MOCKED_RESPONSE = Symbol('isMockedResponse');
 const activeClientIds = new Set();
 
 self.addEventListener('install', function () {
-  return self.skipWaiting();
+  self.skipWaiting();
 });
 
-self.addEventListener('activate', async function (event) {
-  return self.clients.claim();
+self.addEventListener('activate', function (event) {
+  event.waitUntil(self.clients.claim());
 });
 
 self.addEventListener('message', async function (event) {
@@ -33,7 +33,9 @@ self.addEventListener('message', async function (event) {
     return;
   }
 
-  const allClients = await self.clients.matchAll();
+  const allClients = await self.clients.matchAll({
+    type: 'window',
+  });
 
   switch (event.data) {
     case 'KEEPALIVE_REQUEST': {
@@ -83,165 +85,8 @@ self.addEventListener('message', async function (event) {
   }
 });
 
-// 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();
-
-  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 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 clonedResponse = response.clone();
-      sendToClient(client, {
-        type: 'RESPONSE',
-        payload: {
-          requestId,
-          type: clonedResponse.type,
-          ok: clonedResponse.ok,
-          status: clonedResponse.status,
-          statusText: clonedResponse.statusText,
-          body: clonedResponse.body === null ? null : await clonedResponse.text(),
-          headers: serializeHeaders(clonedResponse.headers),
-          redirected: clonedResponse.redirected,
-        },
-      });
-    })();
-  }
-
-  return response;
-}
-
-async function getResponse(event, client, requestId) {
-  const { request } = event;
-  const requestClone = request.clone();
-  const getOriginalResponse = () => fetch(requestClone);
-
-  // Bypass mocking when the request client is not active.
-  if (!client) {
-    return getOriginalResponse();
-  }
-
-  // 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 await getOriginalResponse();
-  }
-
-  // Bypass requests with the explicit bypass header
-  if (requestClone.headers.get(bypassHeaderName) === 'true') {
-    const cleanRequestHeaders = serializeHeaders(requestClone.headers);
-
-    // Remove the bypass header to comply with the CORS preflight check.
-    delete cleanRequestHeaders[bypassHeaderName];
-
-    const originalRequest = new Request(requestClone, {
-      headers: new Headers(cleanRequestHeaders),
-    });
-
-    return fetch(originalRequest);
-  }
-
-  // Send the request to the client-side MSW.
-  const reqHeaders = serializeHeaders(request.headers);
-  const body = await request.text();
-
-  const clientMessage = await sendToClient(client, {
-    type: 'REQUEST',
-    payload: {
-      id: requestId,
-      url: request.url,
-      method: request.method,
-      headers: reqHeaders,
-      cache: request.cache,
-      mode: request.mode,
-      credentials: request.credentials,
-      destination: request.destination,
-      integrity: request.integrity,
-      redirect: request.redirect,
-      referrer: request.referrer,
-      referrerPolicy: request.referrerPolicy,
-      body,
-      bodyUsed: request.bodyUsed,
-      keepalive: request.keepalive,
-    },
-  });
-
-  switch (clientMessage.type) {
-    case 'MOCK_SUCCESS': {
-      return delayPromise(() => respondWithMock(clientMessage), clientMessage.payload.delay);
-    }
-
-    case 'MOCK_NOT_FOUND': {
-      return getOriginalResponse();
-    }
-
-    case 'NETWORK_ERROR': {
-      const { name, message } = clientMessage.payload;
-      const networkError = new Error(message);
-      networkError.name = name;
-
-      // Rejecting a request Promise emulates a network error.
-      throw networkError;
-    }
-
-    case 'INTERNAL_ERROR': {
-      const parsedBody = JSON.parse(clientMessage.payload.body);
-
-      console.error(
-        `\
-[MSW] Uncaught exception in the request handler for "%s %s":
-
-${parsedBody.location}
-
-This exception has been gracefully handled as a 500 response, however, it's strongly recommended to resolve this error, as it indicates a mistake in your code. If you wish to mock an error response, please see this guide: https://mswjs.io/docs/recipes/mocking-error-responses\
-`,
-        request.method,
-        request.url
-      );
-
-      return respondWithMock(clientMessage);
-    }
-  }
-
-  return getOriginalResponse();
-}
-
 self.addEventListener('fetch', function (event) {
   const { request } = event;
-  const accept = request.headers.get('accept') || '';
-
-  // Bypass server-sent events.
-  if (accept.includes('text/event-stream')) {
-    return;
-  }
 
   // Bypass navigation requests.
   if (request.mode === 'navigate') {
@@ -261,36 +106,149 @@ self.addEventListener('fetch', function (event) {
     return;
   }
 
-  const requestId = uuidv4();
-
-  return event.respondWith(
-    handleRequest(event, requestId).catch((error) => {
-      if (error.name === 'NetworkError') {
-        console.warn('[MSW] Successfully emulated a network error for the "%s %s" request.', request.method, request.url);
-        return;
-      }
-
-      // At this point, any exception indicates an issue with the original request/response.
-      console.error(
-        `\
-[MSW] Caught an exception from the "%s %s" request (%s). This is probably not a problem with Mock Service Worker. There is likely an additional logging output above.`,
-        request.method,
-        request.url,
-        `${error.name}: ${error.message}`
-      );
-    })
-  );
+  // Generate unique request ID.
+  const requestId = crypto.randomUUID();
+  event.respondWith(handleRequest(event, requestId));
 });
 
-function serializeHeaders(headers) {
-  const reqHeaders = {};
-  headers.forEach((value, name) => {
-    reqHeaders[name] = reqHeaders[name] ? [].concat(reqHeaders[name]).concat(value) : value;
-  });
-  return reqHeaders;
+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;
 }
 
-function sendToClient(client, message) {
+// 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();
 
@@ -302,27 +260,25 @@ function sendToClient(client, message) {
       resolve(event.data);
     };
 
-    client.postMessage(JSON.stringify(message), [channel.port2]);
+    client.postMessage(message, [channel.port2].concat(transferrables.filter(Boolean)));
   });
 }
 
-function delayPromise(cb, duration) {
-  return new Promise((resolve) => {
-    setTimeout(() => resolve(cb()), duration);
-  });
-}
+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();
+  }
 
-function respondWithMock(clientMessage) {
-  return new Response(clientMessage.payload.body, {
-    ...clientMessage.payload,
-    headers: clientMessage.payload.headers,
-  });
-}
+  const mockedResponse = new Response(response.body, response);
 
-function uuidv4() {
-  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
-    const r = (Math.random() * 16) | 0;
-    const v = c == 'x' ? r : (r & 0x3) | 0x8;
-    return v.toString(16);
+  Reflect.defineProperty(mockedResponse, IS_MOCKED_RESPONSE, {
+    value: true,
+    enumerable: true,
   });
+
+  return mockedResponse;
 }