feat: webExtension module

src/bidiMapper/BidiNoOpParser.ts

@@ -26,6 +26,7 @@ import type {
   Storage,
   Permissions,
   Bluetooth,
+  WebExtension,
 } from '../protocol/protocol.js';
 
 import type {BidiCommandParameterParser} from './BidiParser.js';
@@ -232,4 +233,14 @@ export class BidiNoOpParser implements BidiCommandParameterParser {
     return params as Storage.SetCookieParameters;
   }
   // keep-sorted end
+
+  // WebExtenstion module
+  // keep-sorted start block=yes
+  parseInstallParams(params: unknown): WebExtension.InstallParameters {
+    return params as WebExtension.InstallParameters;
+  }
+  parseUninstallParams(params: unknown): WebExtension.UninstallParameters {
+    return params as WebExtension.UninstallParameters;
+  }
+  // keep-sorted end
 }

src/bidiMapper/BidiParser.ts

@@ -26,6 +26,7 @@ import type {
   Script,
   Session,
   Storage,
+  WebExtension,
 } from '../protocol/protocol.js';
 
 export interface BidiCommandParameterParser {
@@ -146,4 +147,10 @@ export interface BidiCommandParameterParser {
   parseGetCookiesParams(params: unknown): Storage.GetCookiesParameters;
   parseSetCookieParams(params: unknown): Storage.SetCookieParameters;
   // keep-sorted end
+
+  // WebExtenstion module
+  // keep-sorted start block=yes
+  parseInstallParams(params: unknown): WebExtension.InstallParameters;
+  parseUninstallParams(params: unknown): WebExtension.UninstallParameters;
+  // keep-sorted end
 }

src/bidiMapper/CommandProcessor.ts

@@ -46,6 +46,7 @@ import {ScriptProcessor} from './modules/script/ScriptProcessor.js';
 import type {EventManager} from './modules/session/EventManager.js';
 import {SessionProcessor} from './modules/session/SessionProcessor.js';
 import {StorageProcessor} from './modules/storage/StorageProcessor.js';
+import {WebExtensionProcessor} from './modules/webExtension/WebExtensionProcessor.js';
 import {OutgoingMessage} from './OutgoingMessage.js';
 
 export const enum CommandProcessorEvents {
@@ -71,6 +72,7 @@ export class CommandProcessor extends EventEmitter<CommandProcessorEventsMap> {
   #scriptProcessor: ScriptProcessor;
   #sessionProcessor: SessionProcessor;
   #storageProcessor: StorageProcessor;
+  #webExtensionProcessor: WebExtensionProcessor;
   // keep-sorted end
 
   #parser: BidiCommandParameterParser;
@@ -134,6 +136,7 @@ export class CommandProcessor extends EventEmitter<CommandProcessorEventsMap> {
       browsingContextStorage,
       logger,
     );
+    this.#webExtensionProcessor = new WebExtensionProcessor(browserCdpClient);
     // keep-sorted end
   }
 
@@ -402,8 +405,8 @@ export class CommandProcessor extends EventEmitter<CommandProcessorEventsMap> {
       // WebExtension module
       // keep-sorted start block=yes
       case 'webExtension.install':
-        throw new UnknownErrorException(
-          `Method ${command.method} is not implemented.`,
+        return await this.#webExtensionProcessor.install(
+          this.#parser.parseInstallParams(command.params),
         );
       case 'webExtension.uninstall':
         throw new UnknownErrorException(

src/bidiMapper/modules/webExtension/WebExtensionProcessor.ts

@@ -0,0 +1,68 @@
+/**
+ * Copyright 2025 Google LLC.
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * Copyright 2023 Google LLC.
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import type {CdpClient} from '../../../cdp/CdpClient.js';
+import {
+  InvalidWebExtensionException,
+  type WebExtension,
+} from '../../../protocol/protocol.js';
+
+/**
+ * Responsible for handling the `storage` module.
+ */
+export class WebExtensionProcessor {
+  readonly #browserCdpClient: CdpClient;
+
+  constructor(browserCdpClient: CdpClient) {
+    this.#browserCdpClient = browserCdpClient;
+  }
+
+  async install(
+    params: WebExtension.InstallParameters,
+  ): Promise<WebExtension.InstallResult> {
+    try {
+      const response = await this.#browserCdpClient.sendCommand(
+        'Extensions.loadUnpacked',
+        {
+          path: (params.extensionData as WebExtension.ExtensionArchivePath)
+            .path,
+        },
+      );
+      return {
+        extension: response.id,
+      };
+    } catch (err: any) {
+      throw new InvalidWebExtensionException(err.toString());
+    }
+  }
+}

src/bidiTab/BidiParser.ts

@@ -26,6 +26,7 @@ import type {
   Script,
   Session,
   Storage,
+  WebExtension,
 } from '../protocol/protocol.js';
 import * as Parser from '../protocol-parser/protocol-parser.js';
 
@@ -231,4 +232,14 @@ export class BidiParser implements BidiCommandParameterParser {
     return Parser.Storage.parseSetCookieParams(params);
   }
   // keep-sorted end
+
+  // WebExtenstion module
+  // keep-sorted start block=yes
+  parseInstallParams(params: unknown): WebExtension.InstallParameters {
+    return Parser.WebModule.parseInstallParams(params);
+  }
+  parseUninstallParams(params: unknown): WebExtension.UninstallParameters {
+    return Parser.WebModule.parseUninstallParams(params);
+  }
+  // keep-sorted end
 }

src/protocol-parser/protocol-parser.ts

@@ -433,3 +433,23 @@ export namespace Bluetooth {
     ) as Protocol.Bluetooth.SimulatePreconnectedPeripheralParameters;
   }
 }
+
+/** @see https://w3c.github.io/webdriver-bidi/#module-webExtension */
+export namespace WebModule {
+  export function parseInstallParams(
+    params: unknown,
+  ): Protocol.WebExtension.InstallParameters {
+    return parseObject(
+      params,
+      WebDriverBidi.WebExtension.InstallParametersSchema,
+    );
+  }
+  export function parseUninstallParams(
+    params: unknown,
+  ): Protocol.WebExtension.UninstallParameters {
+    return parseObject(
+      params,
+      WebDriverBidi.WebExtension.UninstallParametersSchema,
+    );
+  }
+}