[js][bidi] Add request and response handler

Author: pujagani

javascript/selenium-webdriver/bidi/network.js

@@ -154,26 +154,26 @@ class Network {
 
     this.ws = await this.bidi.socket
     this.ws.on('message', (event) => {
-      const { params } = JSON.parse(Buffer.from(event.toString()))
+      const { method, params } = JSON.parse(Buffer.from(event.toString()))
       if (params) {
         let response = null
-        if ('initiator' in params) {
-          response = new BeforeRequestSent(
+        if ('request' in params && 'response' in params) {
+          response = new ResponseStarted(
             params.context,
             params.navigation,
             params.redirectCount,
             params.request,
             params.timestamp,
-            params.initiator,
+            params.response,
           )
-        } else if ('response' in params) {
-          response = new ResponseStarted(
+        } else if ('initiator' in params && !('response' in params)) {
+          response = new BeforeRequestSent(
             params.context,
             params.navigation,
             params.redirectCount,
             params.request,
             params.timestamp,
-            params.response,
+            params.initiator,
           )
         } else if ('errorText' in params) {
           response = new FetchError(
@@ -185,7 +185,7 @@ class Network {
             params.errorText,
           )
         }
-        this.invokeCallbacks(eventType, response)
+        this.invokeCallbacks(method, response)
       }
     })
     return id

javascript/selenium-webdriver/bidi/networkTypes.js

@@ -118,6 +118,17 @@ class Header {
   get value() {
     return this._value
   }
+
+  /**
+   * Converts the Header to a map.
+   * @returns {Map<string, string>} A map representation of the Header.
+   */
+  asMap() {
+    const map = new Map()
+    map.set('name', this._name)
+    map.set('value', Object.fromEntries(this._value.asMap()))
+    return map
+  }
 }
 
 /**

javascript/selenium-webdriver/lib/http.js

@@ -88,12 +88,18 @@ class Request {
    * @param {string} method The HTTP method to use for the request.
    * @param {string} path The path on the server to send the request to.
    * @param {Object=} opt_data This request's non-serialized JSON payload data.
+   * @param {Map<string, string>} [headers=new Map()] - The optional headers as a Map.
    */
-  constructor(method, path, opt_data) {
+  constructor(method, path, opt_data, headers = new Map()) {
     this.method = /** string */ method
     this.path = /** string */ path
     this.data = /** Object */ opt_data
-    this.headers = /** !Map<string, string> */ new Map([['Accept', 'application/json; charset=utf-8']])
+
+    if (headers.size > 0) {
+      this.headers = headers
+    } else {
+      this.headers = /** !Map<string, string> */ new Map([['Accept', 'application/json; charset=utf-8']])
+    }
   }
 
   /** @override */

javascript/selenium-webdriver/lib/network.js

@@ -18,12 +18,18 @@
 const { Network: getNetwork } = require('../bidi/network')
 const { InterceptPhase } = require('../bidi/interceptPhase')
 const { AddInterceptParameters } = require('../bidi/addInterceptParameters')
+const { ContinueRequestParameters } = require('../bidi/continueRequestParameters')
+const { ProvideResponseParameters } = require('../bidi/provideResponseParameters')
+const { Request } = require('./http')
+const { BytesValue, Header } = require('../bidi/networkTypes')
 
 class Network {
   #callbackId = 0
   #driver
   #network
   #authHandlers = new Map()
+  #requestHandlers = new Map()
+  #responseHandlers = new Map()
 
   constructor(driver) {
     this.#driver = driver
@@ -43,6 +49,8 @@ class Network {
 
     await this.#network.addIntercept(new AddInterceptParameters(InterceptPhase.AUTH_REQUIRED))
 
+    await this.#network.addIntercept(new AddInterceptParameters(InterceptPhase.BEFORE_REQUEST_SENT))
+
     await this.#network.authRequired(async (event) => {
       const requestId = event.request.request
       const uri = event.request.url
@@ -54,6 +62,76 @@ class Network {
 
       await this.#network.continueWithAuthNoCredentials(requestId)
     })
+
+    await this.#network.beforeRequestSent(async (event) => {
+      const requestId = event.request.request
+      const requestData = event.request
+
+      // Build the original request from the intercepted request details.
+      const originalRequest = new Request(requestData.method, requestData.url, null, new Map(requestData.headers))
+
+      let requestHandler = this.getRequestHandler(originalRequest)
+      let responseHandler = this.getResponseHandler(originalRequest)
+
+      // Populate the headers of the original request.
+      // Body is not available as part of WebDriver Spec, hence we cannot add that or use that.
+
+      const continueRequestParams = new ContinueRequestParameters(requestId)
+
+      // If a response handler exists, we mock the response instead of modifying the outgoing request
+      if (responseHandler !== null) {
+        const modifiedResponse = await responseHandler()
+
+        const provideResponseParams = new ProvideResponseParameters(requestId)
+        provideResponseParams.statusCode(modifiedResponse.status)
+
+        // Convert headers
+        if (modifiedResponse.headers.size > 0) {
+          const headers = []
+
+          modifiedResponse.headers.forEach((value, key) => {
+            headers.push(new Header(key, new BytesValue('string', value)))
+          })
+          provideResponseParams.headers(headers)
+        }
+
+        // Convert body if available
+        if (modifiedResponse.body && modifiedResponse.body.length > 0) {
+          provideResponseParams.body(new BytesValue('string', modifiedResponse.body))
+        }
+
+        await this.#network.provideResponse(provideResponseParams)
+        return
+      }
+
+      // If request handler exists, modify the request
+      if (requestHandler !== null) {
+        const modifiedRequest = requestHandler(originalRequest)
+
+        continueRequestParams.method(modifiedRequest.method)
+
+        if (originalRequest.path !== modifiedRequest.path) {
+          continueRequestParams.url(modifiedRequest.path)
+        }
+
+        // Convert headers
+        if (modifiedRequest.headers.size > 0) {
+          const headers = []
+
+          modifiedRequest.headers.forEach((value, key) => {
+            headers.push(new Header(key, new BytesValue('string', value)))
+          })
+          continueRequestParams.headers(headers)
+        }
+
+        if (modifiedRequest.data && modifiedRequest.data.length > 0) {
+          continueRequestParams.body(new BytesValue('string', modifiedRequest.data))
+        }
+      }
+
+      // Continue with the modified or original request
+      await this.#network.continueRequest(continueRequestParams)
+    })
   }
 
   getAuthCredentials(uri) {
@@ -64,6 +142,27 @@ class Network {
     }
     return null
   }
+
+  getRequestHandler(req) {
+    for (let [, value] of this.#requestHandlers) {
+      const filter = value.filter
+      if (filter(req)) {
+        return value.handler
+      }
+    }
+    return null
+  }
+
+  getResponseHandler(req) {
+    for (let [, value] of this.#responseHandlers) {
+      const filter = value.filter
+      if (filter(req)) {
+        return value.handler
+      }
+    }
+    return null
+  }
+
   async addAuthenticationHandler(username, password, uri = '//') {
     await this.#init()
 
@@ -86,6 +185,82 @@ class Network {
   async clearAuthenticationHandlers() {
     this.#authHandlers.clear()
   }
+
+  /**
+   * Adds a request handler that filters requests based on a predicate function.
+   * @param {Function} filter - A function that takes an HTTP request and returns true or false.
+   * @param {Function} handler - A function that takes an HTTP request and returns a modified request.
+   * @returns {number} - A unique handler ID.
+   * @throws {Error} - If filter is not a function or handler does not return a request.
+   */
+  async addRequestHandler(filter, handler) {
+    if (typeof filter !== 'function') {
+      throw new Error('Filter must be a function.')
+    }
+
+    if (typeof handler !== 'function') {
+      throw new Error('Handler must be a function.')
+    }
+
+    await this.#init()
+
+    const id = this.#callbackId++
+
+    this.#requestHandlers.set(id, { filter, handler })
+    return id
+  }
+
+  async removeRequestHandler(id) {
+    await this.#init()
+
+    if (this.#requestHandlers.has(id)) {
+      this.#requestHandlers.delete(id)
+    } else {
+      throw Error(`Callback with id ${id} not found`)
+    }
+  }
+
+  async clearRequestHandlers() {
+    this.#requestHandlers.clear()
+  }
+
+  /**
+   * Adds a response handler that mocks responses.
+   * @param {Function} filter - A function that takes an HTTP request, returning a boolean.
+   * @param {Function} handler - A function that returns a mocked HTTP response.
+   * @returns {number} - A unique handler ID.
+   * @throws {Error} - If filter is not a function or handler is not an async function.
+   */
+  async addResponseHandler(filter, handler) {
+    if (typeof filter !== 'function') {
+      throw new Error('Filter must be a function.')
+    }
+
+    if (typeof handler !== 'function') {
+      throw new Error('Handler must be a function.')
+    }
+
+    await this.#init()
+
+    const id = this.#callbackId++
+
+    this.#responseHandlers.set(id, { filter, handler })
+    return id
+  }
+
+  async removeResponseHandler(id) {
+    await this.#init()
+
+    if (this.#responseHandlers.has(id)) {
+      this.#responseHandlers.delete(id)
+    } else {
+      throw Error(`Callback with id ${id} not found`)
+    }
+  }
+
+  async clearResponseHandlers() {
+    this.#responseHandlers.clear()
+  }
 }
 
 module.exports = Network

javascript/selenium-webdriver/lib/test/fileserver.js

@@ -45,6 +45,7 @@ const Pages = (function () {
     })
   }
 
+  addPage('addRequestBody', 'addRequestBody')
   addPage('ajaxyPage', 'ajaxy_page.html')
   addPage('alertsPage', 'alerts.html')
   addPage('basicAuth', 'basicAuth')
@@ -131,6 +132,7 @@ const Path = {
   PAGE: WEB_ROOT + '/page',
   SLEEP: WEB_ROOT + '/sleep',
   UPLOAD: WEB_ROOT + '/upload',
+  ADD_REQUEST_BODY: WEB_ROOT + '/addRequestBody',
 }
 
 var app = express()
@@ -143,6 +145,7 @@ app
   })
   .use(JS_ROOT, serveIndex(jsDirectory), express.static(jsDirectory))
   .post(Path.UPLOAD, handleUpload)
+  .post(Path.ADD_REQUEST_BODY, addRequestBody)
   .use(WEB_ROOT, serveIndex(baseDirectory), express.static(baseDirectory))
   .use(DATA_ROOT, serveIndex(dataDirectory), express.static(dataDirectory))
   .get(Path.ECHO, sendEcho)
@@ -187,6 +190,32 @@ function sendInifinitePage(request, response) {
   response.end(body)
 }
 
+function addRequestBody(request, response) {
+  let requestBody = ''
+
+  request.on('data', (chunk) => {
+    requestBody += chunk
+  })
+
+  request.on('end', () => {
+    let body = [
+      '<!DOCTYPE html>',
+      '<html>',
+      '<head><title>Page</title></head>',
+      '<body>',
+      `<p>Request Body:</p><pre>${requestBody}</pre>`,
+      '</body>',
+      '</html>',
+    ].join('')
+
+    response.writeHead(200, {
+      'Content-Length': Buffer.byteLength(body, 'utf8'),
+      'Content-Type': 'text/html; charset=utf-8',
+    })
+    response.end(body)
+  })
+}
+
 function sendBasicAuth(request, response) {
   const denyAccess = function () {
     response.writeHead(401, { 'WWW-Authenticate': 'Basic realm="test"' })