Add handling for dynamic strings

package.json

@@ -20,6 +20,7 @@
   },
   "devDependencies": {
     "@rollup/plugin-eslint": "^9.0.5",
+    "@rollup/plugin-node-resolve": "^15.2.3",
     "@rollup/plugin-typescript": "^11.1.5",
     "@types/chrome": "^0.0.248",
     "@types/jest": "^29.4.0",
@@ -33,5 +34,8 @@
     "ts-jest": "^29.0.0",
     "tslib": "^2.5.0",
     "typescript": "^5.2.2"
+  },
+  "dependencies": {
+    "acorn": "^8.11.3"
   }
 }

rollup.config.ts

@@ -10,6 +10,7 @@ import type {Plugin, RollupOptions} from 'rollup';
 import cleanOnce from './build/rollup-plugin-clean-once';
 import eslintPlugin from '@rollup/plugin-eslint';
 import typescript from '@rollup/plugin-typescript';
+import nodeResolve from '@rollup/plugin-node-resolve';
 import prettierBuildStart from './build/rollup-plugin-prettier-build-start';
 import staticFiles from './build/rollup-plugin-static-files';
 import watch from './build/rollup-plugin-watch-additional';
@@ -45,7 +46,7 @@ const config: Array<RollupOptions> = contentScriptSteps.concat([
       file: `dist/${target}/background.js`,
       format: 'iife',
     })),
-    plugins: [typescript(), prettierSrc(), eslint()],
+    plugins: [typescript(), prettierSrc(), eslint(), nodeResolve()],
   },
   {
     input: 'src/js/popup.ts',

src/js/__tests__/removeDynamicStrings-test.js

@@ -0,0 +1,55 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+'use strict';
+
+import {removeDynamicStrings} from '../background/removeDynamicStrings';
+
+describe('removeDynamicStrings', () => {
+  it('Handles different quote types', () => {
+    expect(
+      removeDynamicStrings(`const foo = /*BTDS*/'dynamic string';`),
+    ).toEqual(`const foo = /*BTDS*/'';`);
+    expect(
+      removeDynamicStrings(`const foo = /*BTDS*/"dynamic string";`),
+    ).toEqual(`const foo = /*BTDS*/"";`);
+  });
+  it('Handles strings in different scenarios', () => {
+    expect(removeDynamicStrings(`/*BTDS*/'dynamic string';`)).toEqual(
+      `/*BTDS*/'';`,
+    );
+    expect(
+      removeDynamicStrings(
+        `/*BTDS*/'dynamic string' + /*BTDS*/'dynamic string';`,
+      ),
+    ).toEqual(`/*BTDS*/'' + /*BTDS*/'';`);
+    expect(
+      removeDynamicStrings(`const foo = JSON.parse(/*BTDS*/'dynamic string');`),
+    ).toEqual(`const foo = JSON.parse(/*BTDS*/'');`);
+    expect(
+      removeDynamicStrings("`before ${/*BTDS*/'dynamic string'} after`;"),
+    ).toEqual("`before ${/*BTDS*/''} after`;");
+  });
+  it('Handles multiple strings', () => {
+    expect(
+      removeDynamicStrings(
+        `/*BTDS*/'dynamic string';/*BTDS*/'dynamic string';/*BTDS*/'dynamic string';`,
+      ),
+    ).toEqual(`/*BTDS*/'';/*BTDS*/'';/*BTDS*/'';`);
+  });
+  it('Handles strings across line breaks', () => {
+    expect(
+      removeDynamicStrings(`/*BTDS*/'dynamic \
+      string';`),
+    ).toEqual(`/*BTDS*/'';`);
+  });
+  it('Throws if parsing fails', () => {
+    expect(() =>
+      removeDynamicStrings(`const foo = JSON.parse(/*BTDS*/'dynamic string';`),
+    ).toThrow();
+  });
+});

src/js/__tests__/serviceWorkerE2E-test.js

@@ -0,0 +1,51 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+'use strict';
+
+import {removeDynamicStrings} from '../background/removeDynamicStrings';
+import {createHash} from 'crypto';
+
+const packages = getSampleResponse().split('/*FB_PKG_DELIM*/\n');
+const trimmedPackages = packages.map(pkg => pkg.trimStart());
+const packagesWithStringRemoved = trimmedPackages.map(removeDynamicStrings);
+const hashes = packagesWithStringRemoved.map(pkg =>
+  createHash('sha256').update(pkg).digest('hex'),
+);
+
+describe('serviceWorker end to end', () => {
+  it('Should split on the delimiter', () => {
+    expect(packages).toHaveLength(4);
+  });
+  it('Should identify packages with dynamic strings', () => {
+    expect(packages.filter(pkg => pkg.includes('/*BTDS*/'))).toHaveLength(3);
+  });
+  it('Should hash the dynamic packages', () => {
+    expect(hashes).toEqual([
+      '4c8dc7ae702b26a0bae9c60f93f8bb6e233c406b119c6d9f0289d9a304c4257f',
+      '61a916dff3b6a2f84e1e67fa4b17dc94c340f37ffb6b203a5a1b418d143a08ae',
+      '12af311c30cdf809dfd3f6fb3597c93f4366dd837aa48318e806e7621ebe5058',
+      '94dd9337b54dd0f617468a3c15010252353c1441cbc85dfd540022c566ac8075',
+    ]);
+  });
+});
+
+function getSampleResponse() {
+  return `__DEV__=1;typeof window === 'object' && Object.defineProperty(window,'__DEV__',{set(){},get(){return 1}});/*FB_PKG_DELIM*/
+self.__swData=JSON.parse(/*BTDS*/"{}");/*FB_PKG_DELIM*/
+self.SW_LOGGING_URL = /*BTDS*/"https:\/\/www.my-od.instagram.com\/sw\/log\/init\/";/*FB_PKG_DELIM*/
+
+      if (self.trustedTypes && self.trustedTypes.createPolicy) {
+        const escapeScriptURLPolicy = self.trustedTypes.createPolicy("workerPolicy", {
+          createScriptURL: url => url
+        });
+        importScripts(escapeScriptURLPolicy.createScriptURL(/*BTDS*/"https:\/\/www.my-od.facebook.com\/intern\/rsrc.php\/v3\/yo\/js\/service_workers\/InstagramWebServiceWorker.bundle.js?_=er_xlCBVeZr&p_content_refs=readable&p_js_user_agent=modern_es6&p_function_visitor=on&p_min=no_min&p_inline_require_opt=no_regen&p_forget=off&p_patch=off&p_locale=en_US&origin=www.my-od.instagram.com&sourcemaps=1&_nc_x=Ij3Wp8lg5Kz"));
+      } else {
+         importScripts(/*BTDS*/"https:\/\/www.my-od.facebook.com\/intern\/rsrc.php\/v3\/yo\/js\/service_workers\/InstagramWebServiceWorker.bundle.js?_=er_xlCBVeZr&p_content_refs=readable&p_js_user_agent=modern_es6&p_function_visitor=on&p_min=no_min&p_inline_require_opt=no_regen&p_forget=off&p_patch=off&p_locale=en_US&origin=www.my-od.instagram.com&sourcemaps=1&_nc_x=Ij3Wp8lg5Kz");
+      }
+      `;
+}

src/js/background.ts

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import {Origin, STATES} from './config';
+import {DYNAMIC_STRING_MARKER, Origin, STATES} from './config';
 import {MESSAGE_TYPE, ORIGIN_HOST, ORIGIN_TIMEOUT} from './config';
 
 import {
@@ -16,6 +16,7 @@ import setupCSPListener from './background/setupCSPListener';
 import setUpWebRequestsListener from './background/setUpWebRequestsListener';
 import {validateMetaCompanyManifest} from './background/validateMetaCompanyManifest';
 import {validateSender} from './background/validateSender';
+import {removeDynamicStrings} from './background/removeDynamicStrings';
 import {MessagePayload, MessageResponse} from './shared/MessageTypes';
 import {setOrUpdateSetInMap} from './shared/nestedDataHelpers';
 
@@ -149,6 +150,15 @@ function handleMessages(
         return;
       }
 
+      if (message.rawjs.includes(DYNAMIC_STRING_MARKER)) {
+        try {
+          message.rawjs = removeDynamicStrings(message.rawjs);
+        } catch (e) {
+          sendResponse({valid: false, reason: 'failed parsing AST'});
+          return;
+        }
+      }
+
       // fetch the src
       const encoder = new TextEncoder();
       const encodedJS = encoder.encode(message.rawjs);

src/js/background/removeDynamicStrings.ts

@@ -0,0 +1,47 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {Parser} from 'acorn';
+import {DYNAMIC_STRING_MARKER} from '../config';
+
+const markerLength = DYNAMIC_STRING_MARKER.length;
+
+// This variable, and the parser, are reused because extending the
+// parser is surprisingly expensive. This is currently safe because
+// `removeDynamicStrings` is synchronous.
+let ranges = [0];
+function plugin(BaseParser: typeof Parser): typeof Parser {
+  // @ts-ignore third party typing doesn't support extension well.
+  return class extends BaseParser {
+    parseLiteral(value: string) {
+      // @ts-ignore third party typing doesn't support extension well.
+      const node = super.parseLiteral(value);
+      const before = this.input.substring(
+        node.start - markerLength,
+        node.start,
+      );
+      if (before === DYNAMIC_STRING_MARKER) {
+        ranges.push(node.start + 1, node.end - 1);
+      }
+      return node;
+    }
+  };
+}
+
+const extendedParser = Parser.extend(plugin);
+
+export function removeDynamicStrings(rawjs: string): string {
+  ranges = [0];
+  extendedParser.parse(rawjs, {ecmaVersion: 'latest'});
+
+  let result = '';
+  for (let i = 0; i < ranges.length; i += 2) {
+    result += rawjs.substring(ranges[i], ranges[i + 1]);
+  }
+
+  return result;
+}

src/js/config.ts

@@ -130,3 +130,5 @@ export const DOWNLOAD_JS_ENABLED =
   'CompressionStream' in window && 'showSaveFilePicker' in window;
 
 export const MANIFEST_TIMEOUT = 45000;
+
+export const DYNAMIC_STRING_MARKER = '/*BTDS*/';

src/js/contentUtils.ts

@@ -65,6 +65,7 @@ const FOUND_MANIFEST_VERSIONS = new Set<string>();
 type ScriptDetailsWithSrc = {
   otherType: string;
   src: string;
+  isServiceWorker?: boolean;
 };
 type ScriptDetailsRaw = {
   type: typeof MESSAGE_TYPE.RAW_JS;
@@ -355,6 +356,11 @@ async function processJSWithSrc(
     await alertBackgroundOfImminentFetch(script.src);
     const sourceResponse = await fetch(script.src, {
       method: 'GET',
+      // When the browser fetches a service worker it adds this header.
+      // If this is missing it will cause a cache miss, resulting in invalidation.
+      headers: script.isServiceWorker
+        ? {'Service-Worker': 'script'}
+        : undefined,
     });
     if (DOWNLOAD_JS_ENABLED) {
       const fileNameArr = script.src.split('/');
@@ -558,12 +564,6 @@ chrome.runtime.onMessage.addListener(request => {
     );
   } else if (request.greeting === 'checkIfScriptWasProcessed') {
     if (isUserLoggedIn && !ALL_FOUND_SCRIPT_TAGS.has(request.response.url)) {
-      if (
-        'serviceWorker' in navigator &&
-        navigator.serviceWorker.controller?.scriptURL === request.response.url
-      ) {
-        return;
-      }
       const hostname = window.location.hostname;
       const resourceURL = new URL(request.response.url);
       if (resourceURL.hostname === hostname) {
@@ -593,6 +593,7 @@ chrome.runtime.onMessage.addListener(request => {
         uninitializedScripts.push({
           src: request.response.url,
           otherType: currentFilterType,
+          isServiceWorker: hasServiceWorkerHeader(request.response),
         });
       }
       updateCurrentState(STATES.PROCESSING);
@@ -614,3 +615,15 @@ chrome.runtime.onMessage.addListener(request => {
     }
   }
 });
+
+function hasServiceWorkerHeader(
+  response: chrome.webRequest.WebResponseCacheDetails,
+): boolean {
+  return (
+    response.responseHeaders?.find(
+      header =>
+        header.name.includes('vary') &&
+        header.value?.includes('Service-Worker'),
+    ) !== undefined
+  );
+}

yarn.lock

@@ -658,6 +658,18 @@
     "@rollup/pluginutils" "^5.0.1"
     eslint "^8.24.0"
 
+"@rollup/plugin-node-resolve@^15.2.3":
+  version "15.2.3"
+  resolved "https://registry.yarnpkg.com/@rollup/plugin-node-resolve/-/plugin-node-resolve-15.2.3.tgz#e5e0b059bd85ca57489492f295ce88c2d4b0daf9"
+  integrity sha512-j/lym8nf5E21LwBT4Df1VD6hRO2L2iwUeUmP7litikRsVp1H6NWx20NEp0Y7su+7XGc476GnXXc4kFeZNGmaSQ==
+  dependencies:
+    "@rollup/pluginutils" "^5.0.1"
+    "@types/resolve" "1.20.2"
+    deepmerge "^4.2.2"
+    is-builtin-module "^3.2.1"
+    is-module "^1.0.0"
+    resolve "^1.22.1"
+
 "@rollup/plugin-typescript@^11.1.5":
   version "11.1.5"
   resolved "https://registry.yarnpkg.com/@rollup/plugin-typescript/-/plugin-typescript-11.1.5.tgz#039c763bf943a5921f3f42be255895e75764cb91"
@@ -817,6 +829,11 @@
   dependencies:
     undici-types "~5.25.1"
 
+"@types/[email protected]":
+  version "1.20.2"
+  resolved "https://registry.yarnpkg.com/@types/resolve/-/resolve-1.20.2.tgz#97d26e00cd4a0423b4af620abecf3e6f442b7975"
+  integrity sha512-60BCwRFOZCQhDncwQdxxeOEEkbc5dIMccYLwbxsS4TUNeVECQ/pBJ0j09mrHOl/JJvpRPGwO9SvE4nR2Nb/a4Q==
+
 "@types/semver@^7.5.0":
   version "7.5.4"
   resolved "https://registry.yarnpkg.com/@types/semver/-/semver-7.5.4.tgz#0a41252ad431c473158b22f9bfb9a63df7541cff"
@@ -967,6 +984,11 @@ acorn@^8.1.0, acorn@^8.8.1, acorn@^8.9.0:
   resolved "https://registry.yarnpkg.com/acorn/-/acorn-8.10.0.tgz#8be5b3907a67221a81ab23c7889c4c5526b62ec5"
   integrity sha512-F0SAmZ8iUtS//m8DmCTA0jlh6TDKkHQyK6xc6V4KDTyZKA9dnvX9/3sRTVQrWm79glUAZbnmmNcdYwUIHWVybw==
 
+acorn@^8.11.3:
+  version "8.11.3"
+  resolved "https://registry.yarnpkg.com/acorn/-/acorn-8.11.3.tgz#71e0b14e13a4ec160724b38fb7b0f233b1b81d7a"
+  integrity sha512-Y9rRfJG5jcKOE0CLisYbojUjIrIEE7AGMzA/Sm4BslANhbS+cDMpgBdcPT91oJ7OuJ9hYJBx59RjbhxVnrF8Xg==
+
 agent-base@6:
   version "6.0.2"
   resolved "https://registry.yarnpkg.com/agent-base/-/agent-base-6.0.2.tgz#49fff58577cfee3f37176feab4c22e00f86d7f77"
@@ -1174,6 +1196,11 @@ buffer-from@^1.0.0:
   resolved "https://registry.yarnpkg.com/buffer-from/-/buffer-from-1.1.2.tgz#2b146a6fd72e80b4f55d255f35ed59a3a9a41bd5"
   integrity sha512-E+XQCRwSbaaiChtv6k6Dwgc+bx+Bs6vuKJHHl5kox/BaKbhiXzqQOwK4cO22yElGp2OCmjwVhT3HmxgyPGnJfQ==
 
+builtin-modules@^3.3.0:
+  version "3.3.0"
+  resolved "https://registry.yarnpkg.com/builtin-modules/-/builtin-modules-3.3.0.tgz#cae62812b89801e9656336e46223e030386be7b6"
+  integrity sha512-zhaCDicdLuWN5UbN5IMnFqNMhNfo919sH85y2/ea+5Yg9TsTkeZxpL+JLbp6cgYFS4sRLp3YV4S6yDuqVWHYOw==
+
 callsites@^3.0.0:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/callsites/-/callsites-3.1.0.tgz#b3630abd8943432f54b3f0519238e33cd7df2f73"
@@ -1972,6 +1999,13 @@ is-arrayish@^0.2.1:
   resolved "https://registry.yarnpkg.com/is-arrayish/-/is-arrayish-0.2.1.tgz#77c99840527aa8ecb1a8ba697b80645a7a926a9d"
   integrity sha512-zz06S8t0ozoDXMG+ube26zeCTNXcKIPJZJi8hBrF4idCLms4CG9QtK7qBl1boi5ODzFpjswb5JPmHCbMpjaYzg==
 
+is-builtin-module@^3.2.1:
+  version "3.2.1"
+  resolved "https://registry.yarnpkg.com/is-builtin-module/-/is-builtin-module-3.2.1.tgz#f03271717d8654cfcaf07ab0463faa3571581169"
+  integrity sha512-BSLE3HnV2syZ0FK0iMA/yUGplUeMmNz4AW5fnTunbCIqZi4vG3WjJT9FHMy5D69xmAYBHXQhJdALdpwVxV501A==
+  dependencies:
+    builtin-modules "^3.3.0"
+
 is-core-module@^2.13.0:
   version "2.13.0"
   resolved "https://registry.yarnpkg.com/is-core-module/-/is-core-module-2.13.0.tgz#bb52aa6e2cbd49a30c2ba68c42bf3435ba6072db"
@@ -2001,6 +2035,11 @@ is-glob@^4.0.0, is-glob@^4.0.1, is-glob@^4.0.3:
   dependencies:
     is-extglob "^2.1.1"
 
+is-module@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/is-module/-/is-module-1.0.0.tgz#3258fb69f78c14d5b815d664336b4cffb6441591"
+  integrity sha512-51ypPSPCoTEIN9dy5Oy+h4pShgJmPCygKfyRCISBI+JoWT/2oJvK8QPxmwv7b/p239jXrm9M1mlQbyKJ5A152g==
+
 is-number@^7.0.0:
   version "7.0.0"
   resolved "https://registry.yarnpkg.com/is-number/-/is-number-7.0.0.tgz#7535345b896734d5f80c4d06c50955527a14f12b"