DevTools: Parse named source AST in a worker

packages/react-devtools-extensions/firefox/manifest.json

@@ -32,7 +32,7 @@
 
   "devtools_page": "main.html",
 
-  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'",
+  "content_security_policy": "script-src 'self' 'unsafe-eval' blob:; object-src 'self'",
   "web_accessible_resources": [
     "main.html",
     "panel.html",

packages/react-devtools-extensions/package.json

@@ -19,7 +19,6 @@
     "update-mock-source-maps": "node ./src/__tests__/updateMockSourceMaps.js"
   },
   "devDependencies": {
-    "acorn-jsx": "^5.2.0",
     "@babel/core": "^7.11.1",
     "@babel/plugin-proposal-class-properties": "^7.10.4",
     "@babel/plugin-transform-flow-strip-types": "^7.10.4",
@@ -28,6 +27,7 @@
     "@babel/preset-env": "^7.11.0",
     "@babel/preset-flow": "^7.10.4",
     "@babel/preset-react": "^7.10.4",
+    "acorn-jsx": "^5.2.0",
     "archiver": "^3.0.0",
     "babel-core": "^7.0.0-bridge",
     "babel-eslint": "^9.0.0",
@@ -55,7 +55,8 @@
     "web-ext": "^3.0.0",
     "webpack": "^4.43.0",
     "webpack-cli": "^3.3.11",
-    "webpack-dev-server": "^3.10.3"
+    "webpack-dev-server": "^3.10.3",
+    "workerize-loader": "^1.3.0"
   },
   "dependencies": {
     "web-ext": "^4"

packages/react-devtools-extensions/src/__tests__/parseHookNames-test.js

@@ -11,6 +11,37 @@
 // This is done to control if and how the code is transformed at runtime.
 // Do not declare test components within this test file as it is very fragile.
 
+function expectHookNamesToEqual(map, expectedNamesArray) {
+  // Slightly hacky since it relies on the iterable order of values()
+  expect(Array.from(map.values())).toEqual(expectedNamesArray);
+}
+
+function requireText(path, encoding) {
+  const {existsSync, readFileSync} = require('fs');
+  if (existsSync(path)) {
+    return Promise.resolve(readFileSync(path, encoding));
+  } else {
+    return Promise.reject(`File not found "${path}"`);
+  }
+}
+
+const chromeGlobal = {
+  extension: {
+    getURL: jest.fn((...args) => {
+      const {join} = require('path');
+      return join(
+        __dirname,
+        '..',
+        '..',
+        'node_modules',
+        'source-map',
+        'lib',
+        'mappings.wasm',
+      );
+    }),
+  },
+};
+
 describe('parseHookNames', () => {
   let fetchMock;
   let inspectHooks;
@@ -26,6 +57,9 @@ describe('parseHookNames', () => {
     fetchMock = require('jest-fetch-mock');
     fetchMock.enableMocks();
 
+    // Mock out portion of browser API used by parseHookNames to initialize "source-map".
+    global.chrome = chromeGlobal;
+
     inspectHooks = require('react-debug-tools/src/ReactDebugHooks')
       .inspectHooks;
     parseHookNames = require('../parseHookNames').parseHookNames;
@@ -45,44 +79,12 @@ describe('parseHookNames', () => {
     fetchMock.mockIf(/.+$/, request => {
       return requireText(request.url, 'utf8');
     });
-
-    // Mock out portion of browser API used by parseHookNames to initialize "source-map".
-    global.chrome = {
-      extension: {
-        getURL: jest.fn((...args) => {
-          const {join} = require('path');
-          return join(
-            __dirname,
-            '..',
-            '..',
-            'node_modules',
-            'source-map',
-            'lib',
-            'mappings.wasm',
-          );
-        }),
-      },
-    };
   });
 
   afterEach(() => {
     fetch.resetMocks();
   });
 
-  function expectHookNamesToEqual(map, expectedNamesArray) {
-    // Slightly hacky since it relies on the iterable order of values()
-    expect(Array.from(map.values())).toEqual(expectedNamesArray);
-  }
-
-  function requireText(path, encoding) {
-    const {existsSync, readFileSync} = require('fs');
-    if (existsSync(path)) {
-      return Promise.resolve(readFileSync(path, encoding));
-    } else {
-      return Promise.reject(`File not found "${path}"`);
-    }
-  }
-
   async function getHookNamesForComponent(Component, props = {}) {
     const hooksTree = inspectHooks(Component, props, undefined, true);
     const hookNames = await parseHookNames(hooksTree);
@@ -344,3 +346,68 @@ describe('parseHookNames', () => {
     });
   });
 });
+
+describe('parseHookNames worker', () => {
+  let inspectHooks;
+  let parseHookNames;
+  let originalParseHookNamesMock;
+  let workerizedParseHookNamesMock;
+
+  beforeEach(() => {
+    window.Worker = undefined;
+
+    originalParseHookNamesMock = jest.fn();
+    workerizedParseHookNamesMock = jest.fn();
+
+    jest.mock('../parseHookNames/parseHookNames.js', () => {
+      return {
+        __esModule: true,
+        parseHookNames: originalParseHookNamesMock,
+      };
+    });
+
+    jest.mock('../parseHookNames/parseHookNames.worker.js', () => {
+      return {
+        __esModule: true,
+        default: () => ({
+          parseHookNames: workerizedParseHookNamesMock,
+        }),
+      };
+    });
+
+    // Mock out portion of browser API used by parseHookNames to initialize "source-map".
+    global.chrome = chromeGlobal;
+
+    inspectHooks = require('react-debug-tools/src/ReactDebugHooks')
+      .inspectHooks;
+    parseHookNames = require('../parseHookNames').parseHookNames;
+  });
+
+  async function getHookNamesForComponent(Component, props = {}) {
+    const hooksTree = inspectHooks(Component, props, undefined, true);
+    const hookNames = await parseHookNames(hooksTree);
+    return hookNames;
+  }
+
+  it('should use worker when available', async () => {
+    const Component = require('./__source__/__untransformed__/ComponentWithUseState')
+      .Component;
+
+    window.Worker = true;
+    // resets module so mocked worker instance can be updated
+    jest.resetModules();
+    parseHookNames = require('../parseHookNames').parseHookNames;
+
+    await getHookNamesForComponent(Component);
+    expect(workerizedParseHookNamesMock).toHaveBeenCalledTimes(1);
+  });
+
+  it('should use main thread when worker is not available', async () => {
+    const Component = require('./__source__/__untransformed__/ComponentWithUseState')
+      .Component;
+
+    await getHookNamesForComponent(Component);
+    expect(workerizedParseHookNamesMock).toHaveBeenCalledTimes(0);
+    expect(originalParseHookNamesMock).toHaveBeenCalledTimes(1);
+  });
+});

packages/react-devtools-extensions/src/parseHookNames/index.js

@@ -0,0 +1,33 @@
+/* global chrome */
+
+/**
+ * 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.
+ *
+ * @flow
+ */
+
+// This file uses workerize to load ./parseHookNames.worker as a webworker
+// and instanciates it, exposing flow typed functions that can be used
+// on other files.
+
+import * as parseHookNamesModule from './parseHookNames';
+import WorkerizedParseHookNames from './parseHookNames.worker';
+
+type ParseHookNamesModule = typeof parseHookNamesModule;
+
+// $FlowFixMe
+const wasmMappingsURL = chrome.extension.getURL('mappings.wasm');
+
+const workerizedParseHookNames: ParseHookNamesModule = window.Worker
+  ? WorkerizedParseHookNames()
+  : parseHookNamesModule;
+
+type ParseHookNames = $PropertyType<ParseHookNamesModule, 'parseHookNames'>;
+
+export const parseHookNames: ParseHookNames = hooksTree =>
+  workerizedParseHookNames.parseHookNames(hooksTree, wasmMappingsURL);
+
+export const purgeCachedMetadata = workerizedParseHookNames.purgeCachedMetadata;

packages/react-devtools-extensions/src/parseHookNames.js → packages/react-devtools-extensions/src/parseHookNames/parseHookNames.js

@@ -1,5 +1,3 @@
-/* global chrome */
-
 /**
  * Copyright (c) Facebook, Inc. and its affiliates.
  *
@@ -12,8 +10,8 @@
 import {parse} from '@babel/parser';
 import LRU from 'lru-cache';
 import {SourceMapConsumer} from 'source-map';
-import {getHookName} from './astUtils';
-import {areSourceMapsAppliedToErrors} from './ErrorTester';
+import {getHookName} from '../astUtils';
+import {areSourceMapsAppliedToErrors} from '../ErrorTester';
 import {__DEBUG__} from 'react-devtools-shared/src/constants';
 import {getHookSourceLocationKey} from 'react-devtools-shared/src/hookNamesCache';
 
@@ -24,7 +22,7 @@ import type {
 } from 'react-debug-tools/src/ReactDebugHooks';
 import type {HookNames, LRUCache} from 'react-devtools-shared/src/types';
 import type {Thenable} from 'shared/ReactTypes';
-import type {SourceConsumer} from './astUtils';
+import type {SourceConsumer} from '../astUtils';
 
 const SOURCE_MAP_REGEX = / ?sourceMappingURL=([^\s'"]+)/gm;
 const MAX_SOURCE_LENGTH = 100_000_000;
@@ -103,6 +101,7 @@ const originalURLToMetadataCache: LRUCache<
 
 export async function parseHookNames(
   hooksTree: HooksTree,
+  wasmMappingsURL: string,
 ): Thenable<HookNames | null> {
   const hooksList: Array<HooksNode> = [];
   flattenHooksList(hooksTree, hooksList);
@@ -160,7 +159,9 @@ export async function parseHookNames(
   }
 
   return loadSourceFiles(locationKeyToHookSourceData)
-    .then(() => extractAndLoadSourceMaps(locationKeyToHookSourceData))
+    .then(() =>
+      extractAndLoadSourceMaps(locationKeyToHookSourceData, wasmMappingsURL),
+    )
     .then(() => parseSourceAST(locationKeyToHookSourceData))
     .then(() => updateLruCache(locationKeyToHookSourceData))
     .then(() => findHookNames(hooksList, locationKeyToHookSourceData));
@@ -182,6 +183,7 @@ function decodeBase64String(encoded: string): Object {
 
 function extractAndLoadSourceMaps(
   locationKeyToHookSourceData: Map<string, HookSourceData>,
+  wasmMappingsURL: string,
 ): Promise<*> {
   // SourceMapConsumer.initialize() does nothing when running in Node (aka Jest)
   // because the wasm file is automatically read from the file system
@@ -193,9 +195,6 @@ function extractAndLoadSourceMaps(
       );
     }
 
-    // $FlowFixMe
-    const wasmMappingsURL = chrome.extension.getURL('mappings.wasm');
-
     SourceMapConsumer.initialize({'lib/mappings.wasm': wasmMappingsURL});
   }
 

packages/react-devtools-extensions/src/parseHookNames/parseHookNames.worker.js

@@ -0,0 +1,4 @@
+import * as parseHookNamesModule from './parseHookNames';
+
+export const parseHookNames = parseHookNamesModule.parseHookNames;
+export const purgeCachedMetadata = parseHookNamesModule.purgeCachedMetadata;

packages/react-devtools-extensions/webpack.config.js

@@ -109,6 +109,11 @@ module.exports = {
           },
         ],
       },
+      {
+        test: /\.worker\.js$/,
+        // inline: true due to limitations with extensions
+        use: {loader: 'workerize-loader', options: {inline: true}},
+      },
     ],
   },
 };

packages/react-devtools-shared/src/hookNamesCache.js

@@ -18,7 +18,7 @@ import type {
 } from 'react-devtools-shared/src/types';
 import type {HookSource} from 'react-debug-tools/src/ReactDebugHooks';
 
-const TIMEOUT = 5000;
+const TIMEOUT = 30000;
 
 const Pending = 0;
 const Resolved = 1;

yarn.lock

@@ -14877,6 +14877,13 @@ worker-loader@^3.0.2:
     loader-utils "^2.0.0"
     schema-utils "^2.7.0"
 
+workerize-loader@^1.3.0:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/workerize-loader/-/workerize-loader-1.3.0.tgz#4995cf2ff2b45dd6dc60e4411e63f5ae2c704d36"
+  integrity sha512-utWDc8K6embcICmRBUUkzanPgKBb8yM1OHfh6siZfiMsswE8wLCa9CWS+L7AARz0+Th4KH4ZySrqer/OJ9WuWw==
+  dependencies:
+    loader-utils "^2.0.0"
+
 wrap-ansi@^2.0.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/wrap-ansi/-/wrap-ansi-2.1.0.tgz#d8fc3d284dd05794fe84973caecdd1cf824fdd85"