ServiceWorker-based Delta and HMR client

Reviewed By: mjesun

Differential Revision: D10359356

fbshipit-source-id: 79346e488041fa1d14144c0897d6391c07c4d13f

Author: Alexandre Kirszenberg

packages/metro/src/lib/bundle-modules/DeltaClient/__tests__/bundleCache-test.js

@@ -0,0 +1,100 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @emails oncall+js_foundation
+ * @format
+ */
+
+/* eslint-env worker */
+
+'use strict';
+
+const stringToBundle = require('../stringToBundle');
+
+const {getBundle, setBundle} = require('../bundleCache');
+const {Request, Response, Headers} = require('node-fetch');
+const {URL} = require('url');
+
+jest.mock('../stringToBundle');
+
+describe('bundleCache', () => {
+  let putMock;
+  let matchMock;
+  beforeEach(() => {
+    global.fetch = jest.fn();
+    putMock = jest.fn();
+    matchMock = jest.fn();
+
+    global.URL = URL;
+    global.Response = Response;
+    global.Request = Request;
+    global.Headers = Headers;
+    global.caches = {
+      open: jest.fn().mockResolvedValue({
+        put: putMock,
+        match: matchMock,
+      }),
+    };
+  });
+
+  describe('getBundle', () => {
+    it('retrieves a bundle from the bundle cache', async () => {
+      const bundle = {
+        base: true,
+        revisionId: 'revId',
+        pre: 'pre',
+        post: 'post',
+        modules: [[0, '0'], [100, '100']],
+      };
+      const bundleReq = new Request('http://localhost/bundles/cool-bundle');
+      matchMock.mockResolvedValue(new Response(JSON.stringify(bundle)));
+      expect(await getBundle(bundleReq)).toEqual(bundle);
+      expect(fetch).not.toHaveBeenCalled();
+      expect(matchMock).toHaveBeenCalledWith(bundleReq);
+    });
+
+    it('retrieves a bundle from the browser cache', async () => {
+      const stringBundle = 'stringBundle';
+      const bundle = {
+        base: true,
+        revisionId: 'revId',
+        pre: 'pre',
+        post: 'post',
+        modules: [[0, '0'], [100, '100']],
+      };
+      const bundleReq = new Request('http://localhost/bundles/cool-bundle');
+      matchMock.mockResolvedValue(null);
+      fetch.mockResolvedValue(new Response(stringBundle));
+      stringToBundle.mockReturnValue(bundle);
+      expect(await getBundle(bundleReq)).toEqual(bundle);
+      expect(fetch).toHaveBeenCalledWith(bundleReq, {cache: 'force-cache'});
+      expect(stringToBundle).toHaveBeenCalledWith(stringBundle);
+    });
+
+    it('returns null when a bundle cannot be found', async () => {
+      matchMock.mockResolvedValue(null);
+      fetch.mockResolvedValue(null);
+      expect(await getBundle({})).toEqual(null);
+    });
+  });
+
+  describe('setBundle', () => {
+    it('stores a bundle in the bundle cache', async () => {
+      const bundle = {
+        base: true,
+        revisionId: 'revId',
+        pre: 'pre',
+        post: 'post',
+        modules: [[0, '0'], [100, '100']],
+      };
+      const bundleReq = new Request('http://localhost/bundles/cool-bundle');
+      await setBundle(bundleReq, bundle);
+      const putCall = putMock.mock.calls[0];
+      expect(putCall[0]).toBe(bundleReq);
+      expect(await putCall[1].json()).toEqual(bundle);
+    });
+  });
+});

packages/metro/src/lib/bundle-modules/DeltaClient/__tests__/bundleToString-test.js

@@ -0,0 +1,50 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @emails oncall+js_foundation
+ * @format
+ */
+
+'use strict';
+
+const bundleToString = require('../bundleToString');
+
+describe('bundleToString', () => {
+  it('serializes a bundle into a plain JS bundle', () => {
+    expect(
+      bundleToString({
+        base: true,
+        revisionId: 'revisionId',
+        pre: 'console.log("Hello World!");',
+        post: 'console.log("That\'s all folks!");',
+        modules: [[0, 'console.log("Best module.");']],
+      }),
+    ).toMatchInlineSnapshot(`
+"console.log(\\"Hello World!\\");
+console.log(\\"Best module.\\");
+console.log(\\"That's all folks!\\");"
+`);
+  });
+
+  it('modules are sorted by id', () => {
+    expect(
+      bundleToString({
+        base: true,
+        revisionId: 'revisionId',
+        pre: 'console.log("Hello World!");',
+        post: 'console.log("That\'s all folks!");',
+        modules: [[3, '3'], [0, '0'], [2, '2'], [1, '1']],
+      }),
+    ).toMatchInlineSnapshot(`
+"console.log(\\"Hello World!\\");
+0
+1
+2
+3
+console.log(\\"That's all folks!\\");"
+`);
+  });
+});