feat: User agent data simulator

6 files changed, 304 insertions, 0 deletions

diff --git a/packages/service-inject/package.json b/packages/service-inject/package.json
new file mode 100644
index 0000000..e2d03bf
--- /dev/null
+++ b/packages/service-inject/package.json
@@ -0,0 +1,21 @@
+{
+  "name": "@sophie/service-inject",
+  "version": "0.1.0",
+  "private": true,
+  "sideEffects": false,
+  "main": "dist/index.cjs",
+  "types": "dist-types/index.d.ts",
+  "scripts": {
+    "clean": "rimraf dist dist-types tsconfig.tsbuildinfo",
+    "build": "vite build",
+    "typecheck": "tsc"
+  },
+  "dependencies": {
+    "@sophie/service-shared": "workspace:*"
+  },
+  "devDependencies": {
+    "rimraf": "^3.0.2",
+    "typescript": "^4.5.4",
+    "vite": "^2.7.6"
+  }
+}
diff --git a/packages/service-inject/src/index.ts b/packages/service-inject/src/index.ts
new file mode 100644
index 0000000..7f48fdf
--- /dev/null
+++ b/packages/service-inject/src/index.ts
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C)  2021-2022 Kristóf Marussy <kristof@marussy.com>
+ *
+ * This file is part of Sophie.
+ *
+ * Sophie is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { shimUserAgentData } from './shims/userAgentData';
+
+try {
+  shimUserAgentData();
+} catch (err) {
+  console.log('Failed to execute injected script:', err);
+}
diff --git a/packages/service-inject/src/shims/userAgentData.ts b/packages/service-inject/src/shims/userAgentData.ts
new file mode 100644
index 0000000..be43823
--- /dev/null
+++ b/packages/service-inject/src/shims/userAgentData.ts
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C)  2021-2022 Kristóf Marussy <kristof@marussy.com>
+ *
+ * This file is part of Sophie.
+ *
+ * Sophie is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import {
+  defineProtoProperty,
+  deleteProtoProperty,
+  simulateNativeClass,
+  simulateNativeFunction,
+} from '../utils';
+
+export function shimUserAgentData(): void {
+  const brands = [
+    {
+      brand: ' Not A; Brand',
+      version: '99',
+    },
+    {
+      brand: 'Chromium',
+      version: '96',
+    }
+  ];
+  const mobile = false;
+  const platform = 'Linux';
+
+  const simulatedNavigatorUa = simulateNativeClass('NavigatorUAData', function NavigatorUAData() {
+    // Nothing to initiailize.
+  }, {
+    brands: {
+      configurable: true,
+      enumerable: true,
+      get: simulateNativeFunction('brands', () => brands),
+    },
+    mobile: {
+      configurable: true,
+      enumerable: true,
+      get: simulateNativeFunction('mobile', () => mobile),
+    },
+    platform: {
+      configurable: true,
+      enumerable: true,
+      get: simulateNativeFunction('platform', () => platform),
+    },
+    getHighEntropyValues: {
+      configurable: true,
+      enumerable: false,
+      value: simulateNativeFunction('getHighEntropyValues', (...args: unknown[]) => {
+        if (args.length == 0) {
+          throw new TypeError("Failed to execute 'getHighEntropyValues' on 'NavigatorUAData': 1 argument required, but only 0 present.");
+        }
+        const hints = Array.from(args[0] as Iterable<string>);
+        if (hints.length === 0) {
+          return {};
+        }
+        const data: Record<string, unknown> = {
+          brands,
+          mobile,
+        }
+        if (hints.includes('platform')) {
+          data['platform'] = platform;
+        }
+        return Promise.resolve(data);
+      })
+    },
+    toJSON: {
+      configurable: true,
+      enumerable: false,
+      value: simulateNativeFunction('toJSON', () => ({
+        brands,
+        mobile,
+      })),
+      writable: false,
+    },
+  });
+
+  const simulatedUserAgentData = Reflect.construct(simulatedNavigatorUa, []);
+  defineProtoProperty(window.navigator, 'userAgentData', {
+    configurable: true,
+    enumerable: true,
+    get: simulateNativeFunction('userAgentData', () => simulatedUserAgentData),
+  });
+}
+
+export function deleteUserAgentData(): void {
+  deleteProtoProperty(window.navigator, 'userAgentData');
+}
diff --git a/packages/service-inject/src/utils.ts b/packages/service-inject/src/utils.ts
new file mode 100644
index 0000000..4bb3fba
--- /dev/null
+++ b/packages/service-inject/src/utils.ts
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C)  2021-2022 Kristóf Marussy <kristof@marussy.com>
+ *
+ * This file is part of Sophie.
+ *
+ * Sophie is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+/**
+ * Simulates a function defined in native code, i.e., one with
+ * `[native code]` in its `toString`.
+ *
+ * @param name The name of the function.
+ * @param f The function to transform.
+ * @return The transformed function.
+ */
+export function simulateNativeFunction<T, P extends unknown[]>(
+  name: string,
+  f: (this: null, ...args: P) => T,
+): (...args: P) => T {
+  // Bound functions say `[native code]`, but unfortunately they omit the function name:
+  // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/toString#description
+  // The type of `f` contains type variables, so we need some magic type casting.
+  const boundFunc = f.bind(null as ThisParameterType<typeof f>);
+  Object.defineProperty(boundFunc, 'name', {
+    configurable: true,
+    enumerable: false,
+    value: name,
+    writable: false,
+  });
+  return boundFunc;
+}
+
+/**
+ * Simulates a native class available on `globalThis`.
+ *
+ * @param name The name of the class.
+ * @param constructor The constructor function. Must already be a constructor (a named `function`).
+ * @param properties The properties to define on the prototype.
+ */
+export function simulateNativeClass(
+  name: string,
+  constructor: () => void,
+  properties: PropertyDescriptorMap,
+) {
+  Object.defineProperties(constructor.prototype, {
+    [Symbol.toStringTag]: {
+      configurable: true,
+      enumerable: false,
+      value: name,
+      writable: false,
+    },
+    ...properties,
+  });
+  const simulatedConstructor = simulateNativeFunction(name, constructor);
+  Object.defineProperty(globalThis, name, {
+    configurable: true,
+    enumerable: true,
+    value: simulatedConstructor,
+    writable: true,
+  });
+  return simulatedConstructor;
+}
+
+/**
+ * Defines a property on the prototype of an object.
+ *
+ * Only use this with singleton objects, e.g., `window.navigator`.
+ *
+ * @param o The object to modify. Must be a singleton.
+ * @param property The key of the property being defined or modified.
+ * @param attributes The descriptor of the property being defined or modified.
+ */
+export function defineProtoProperty(
+  o: object,
+  property: PropertyKey,
+  attributes: PropertyDescriptor,
+): void {
+  Object.defineProperty(Object.getPrototypeOf(o), property, attributes);
+}
+
+/**
+ * Deletes a property from the prototype of an object.
+ *
+ * Only use this with singleton objects, e.g., `window.navigator`.
+ *
+ * @param o The object to modify. Must be a singleton.
+ * @param property The key of the property being deleted.
+ */
+export function deleteProtoProperty(o: object, property: PropertyKey): void {
+  Reflect.deleteProperty(Object.getPrototypeOf(o), property);
+}
diff --git a/packages/service-inject/tsconfig.json b/packages/service-inject/tsconfig.json
new file mode 100644
index 0000000..4007f60
--- /dev/null
+++ b/packages/service-inject/tsconfig.json
@@ -0,0 +1,22 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "composite": true,
+    "declarationDir": "dist-types",
+    "emitDeclarationOnly": true,
+    "rootDir": "src",
+    "lib": [
+      "dom",
+      "dom.iterable",
+      "esnext"
+    ]
+  },
+  "references": [
+    {
+      "path": "../service-shared"
+    }
+  ],
+  "include": [
+    "src/**/*.ts"
+  ]
+}
diff --git a/packages/service-inject/vite.config.js b/packages/service-inject/vite.config.js
new file mode 100644
index 0000000..9c65c15
--- /dev/null
+++ b/packages/service-inject/vite.config.js
@@ -0,0 +1,28 @@
+// @ts-check
+
+import { builtinModules } from 'module';
+
+import { chrome, makeConfig } from '../../config/vite-common';
+
+/** @type {string} */
+const PACKAGE_ROOT = __dirname;
+
+/**
+ * @type {import('vite').UserConfig}
+ * @see https://vitejs.dev/config/
+ */
+const config = makeConfig({
+  root: PACKAGE_ROOT,
+  build: {
+    target: chrome,
+    lib: {
+      entry: 'src/index.ts',
+      formats: ['cjs'],
+    },
+    rollupOptions: {
+      external: builtinModules,
+    },
+  },
+});
+
+export default config;