Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

5 files changed, 1958 insertions, 0 deletions

diff --git a/remote/webdriver-bidi/modules/root/browsingContext.sys.mjs b/remote/webdriver-bidi/modules/root/browsingContext.sys.mjs
new file mode 100644
index 0000000000..cd8dff6ca0
--- /dev/null
+++ b/remote/webdriver-bidi/modules/root/browsingContext.sys.mjs
@@ -0,0 +1,663 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+import { Module } from "chrome://remote/content/shared/messagehandler/Module.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  AppInfo: "chrome://remote/content/shared/AppInfo.sys.mjs",
+  assert: "chrome://remote/content/shared/webdriver/Assert.sys.mjs",
+  BrowsingContextListener:
+    "chrome://remote/content/shared/listeners/BrowsingContextListener.sys.mjs",
+  capture: "chrome://remote/content/shared/Capture.sys.mjs",
+  ContextDescriptorType:
+    "chrome://remote/content/shared/messagehandler/MessageHandler.sys.mjs",
+  error: "chrome://remote/content/shared/webdriver/Errors.sys.mjs",
+  Log: "chrome://remote/content/shared/Log.sys.mjs",
+  pprint: "chrome://remote/content/shared/Format.sys.mjs",
+  ProgressListener: "chrome://remote/content/shared/Navigate.sys.mjs",
+  TabManager: "chrome://remote/content/shared/TabManager.sys.mjs",
+  waitForInitialNavigationCompleted:
+    "chrome://remote/content/shared/Navigate.sys.mjs",
+  WindowGlobalMessageHandler:
+    "chrome://remote/content/shared/messagehandler/WindowGlobalMessageHandler.sys.mjs",
+  windowManager: "chrome://remote/content/shared/WindowManager.sys.mjs",
+});
+
+XPCOMUtils.defineLazyGetter(lazy, "logger", () =>
+  lazy.Log.get(lazy.Log.TYPES.WEBDRIVER_BIDI)
+);
+
+/**
+ * @typedef {Object} CreateType
+ **/
+
+/**
+ * Enum of types supported by the browsingContext.create command.
+ *
+ * @readonly
+ * @enum {CreateType}
+ **/
+const CreateType = {
+  tab: "tab",
+  window: "window",
+};
+
+/**
+ * @typedef {string} WaitCondition
+ **/
+
+/**
+ * Wait conditions supported by WebDriver BiDi for navigation.
+ *
+ * @enum {WaitCondition}
+ */
+const WaitCondition = {
+  None: "none",
+  Interactive: "interactive",
+  Complete: "complete",
+};
+
+class BrowsingContextModule extends Module {
+  #contextListener;
+  #subscribedEvents;
+
+  /**
+   * Create a new module instance.
+   *
+   * @param {MessageHandler} messageHandler
+   *     The MessageHandler instance which owns this Module instance.
+   */
+  constructor(messageHandler) {
+    super(messageHandler);
+
+    // Create the console-api listener and listen on "message" events.
+    this.#contextListener = new lazy.BrowsingContextListener();
+    this.#contextListener.on("attached", this.#onContextAttached);
+
+    // Set of event names which have active subscriptions.
+    this.#subscribedEvents = new Set();
+  }
+
+  destroy() {
+    this.#contextListener.off("attached", this.#onContextAttached);
+    this.#contextListener.destroy();
+
+    this.#subscribedEvents = null;
+  }
+
+  /**
+   * Capture a base64-encoded screenshot of the provided browsing context.
+   *
+   * @param {Object=} options
+   * @param {string} context
+   *     Id of the browsing context to screenshot.
+   *
+   * @throws {NoSuchFrameError}
+   *     If the browsing context cannot be found.
+   */
+  async captureScreenshot(options = {}) {
+    const { context: contextId } = options;
+
+    lazy.assert.string(
+      contextId,
+      `Expected "context" to be a string, got ${contextId}`
+    );
+    const context = this.#getBrowsingContext(contextId);
+
+    const rect = await this.messageHandler.handleCommand({
+      moduleName: "browsingContext",
+      commandName: "_getScreenshotRect",
+      destination: {
+        type: lazy.WindowGlobalMessageHandler.type,
+        id: context.id,
+      },
+      retryOnAbort: true,
+    });
+
+    const canvas = await lazy.capture.canvas(
+      context.topChromeWindow,
+      context,
+      rect.x,
+      rect.y,
+      rect.width,
+      rect.height
+    );
+
+    return {
+      data: lazy.capture.toBase64(canvas),
+    };
+  }
+
+  /**
+   * Close the provided browsing context.
+   *
+   * @param {Object=} options
+   * @param {string} context
+   *     Id of the browsing context to close.
+   *
+   * @throws {NoSuchFrameError}
+   *     If the browsing context cannot be found.
+   * @throws {InvalidArgumentError}
+   *     If the browsing context is not a top-level one.
+   */
+  async close(options = {}) {
+    const { context: contextId } = options;
+
+    lazy.assert.string(
+      contextId,
+      `Expected "context" to be a string, got ${contextId}`
+    );
+
+    const context = lazy.TabManager.getBrowsingContextById(contextId);
+    if (!context) {
+      throw new lazy.error.NoSuchFrameError(
+        `Browsing Context with id ${contextId} not found`
+      );
+    }
+
+    if (context.parent) {
+      throw new lazy.error.InvalidArgumentError(
+        `Browsing Context with id ${contextId} is not top-level`
+      );
+    }
+
+    if (lazy.TabManager.getTabCount() === 1) {
+      // The behavior when closing the last tab is currently unspecified.
+      // Warn the consumer about potential issues
+      lazy.logger.warn(
+        `Closing the last open tab (Browsing Context id ${contextId}), expect inconsistent behavior across platforms`
+      );
+    }
+
+    const tab = lazy.TabManager.getTabForBrowsingContext(context);
+    await lazy.TabManager.removeTab(tab);
+  }
+
+  /**
+   * Create a new browsing context using the provided type "tab" or "window".
+   *
+   * @param {Object=} options
+   * @param {string=} options.referenceContext
+   *     Id of the top-level browsing context to use as reference.
+   *     If options.type is "tab", the new tab will open in the same window as
+   *     the reference context, and will be added next to the reference context.
+   *     If options.type is "window", the reference context is ignored.
+   * @param {CreateType} options.type
+   *     Type of browsing context to create.
+   *
+   * @throws {InvalidArgumentError}
+   *     If the browsing context is not a top-level one.
+   * @throws {NoSuchFrameError}
+   *     If the browsing context cannot be found.
+   */
+  async create(options = {}) {
+    const { referenceContext: referenceContextId = null, type } = options;
+    if (type !== CreateType.tab && type !== CreateType.window) {
+      throw new lazy.error.InvalidArgumentError(
+        `Expected "type" to be one of ${Object.values(CreateType)}, got ${type}`
+      );
+    }
+
+    let browser;
+    switch (type) {
+      case "window":
+        let newWindow = await lazy.windowManager.openBrowserWindow();
+        browser = lazy.TabManager.getTabBrowser(newWindow).selectedBrowser;
+        break;
+
+      case "tab":
+        if (!lazy.TabManager.supportsTabs()) {
+          throw new lazy.error.UnsupportedOperationError(
+            `browsingContext.create with type "tab" not supported in ${lazy.AppInfo.name}`
+          );
+        }
+
+        let referenceTab;
+        if (referenceContextId !== null) {
+          lazy.assert.string(
+            referenceContextId,
+            lazy.pprint`Expected "referenceContext" to be a string, got ${referenceContextId}`
+          );
+
+          const referenceBrowsingContext = lazy.TabManager.getBrowsingContextById(
+            referenceContextId
+          );
+          if (!referenceBrowsingContext) {
+            throw new lazy.error.NoSuchFrameError(
+              `Browsing Context with id ${referenceContextId} not found`
+            );
+          }
+
+          if (referenceBrowsingContext.parent) {
+            throw new lazy.error.InvalidArgumentError(
+              `referenceContext with id ${referenceContextId} is not a top-level browsing context`
+            );
+          }
+
+          referenceTab = lazy.TabManager.getTabForBrowsingContext(
+            referenceBrowsingContext
+          );
+        }
+
+        const tab = await lazy.TabManager.addTab({
+          focus: false,
+          referenceTab,
+        });
+        browser = lazy.TabManager.getBrowserForTab(tab);
+    }
+
+    await lazy.waitForInitialNavigationCompleted(
+      browser.browsingContext.webProgress
+    );
+
+    return {
+      context: lazy.TabManager.getIdForBrowser(browser),
+    };
+  }
+
+  /**
+   * An object that holds the WebDriver Bidi browsing context information.
+   *
+   * @typedef BrowsingContextInfo
+   *
+   * @property {string} context
+   *     The id of the browsing context.
+   * @property {string=} parent
+   *     The parent of the browsing context if it's the root browsing context
+   *     of the to be processed browsing context tree.
+   * @property {string} url
+   *     The current documents location.
+   * @property {Array<BrowsingContextInfo>=} children
+   *     List of child browsing contexts. Only set if maxDepth hasn't been
+   *     reached yet.
+   */
+
+  /**
+   * An object that holds the WebDriver Bidi browsing context tree information.
+   *
+   * @typedef BrowsingContextGetTreeResult
+   *
+   * @property {Array<BrowsingContextInfo>} contexts
+   *     List of child browsing contexts.
+   */
+
+  /**
+   * Returns a tree of all browsing contexts that are descendents of the
+   * given context, or all top-level contexts when no root is provided.
+   *
+   * @param {Object=} options
+   * @param {number=} maxDepth
+   *     Depth of the browsing context tree to traverse. If not specified
+   *     the whole tree is returned.
+   * @param {string=} root
+   *     Id of the root browsing context.
+   *
+   * @returns {BrowsingContextGetTreeResult}
+   *     Tree of browsing context information.
+   * @throws {NoSuchFrameError}
+   *     If the browsing context cannot be found.
+   */
+  getTree(options = {}) {
+    const { maxDepth = null, root: rootId = null } = options;
+
+    if (maxDepth !== null) {
+      lazy.assert.positiveInteger(
+        maxDepth,
+        `Expected "maxDepth" to be a positive integer, got ${maxDepth}`
+      );
+    }
+
+    let contexts;
+    if (rootId !== null) {
+      // With a root id specified return the context info for itself
+      // and the full tree.
+      lazy.assert.string(
+        rootId,
+        `Expected "root" to be a string, got ${rootId}`
+      );
+      contexts = [this.#getBrowsingContext(rootId)];
+    } else {
+      // Return all top-level browsing contexts.
+      contexts = lazy.TabManager.browsers.map(
+        browser => browser.browsingContext
+      );
+    }
+
+    const contextsInfo = contexts.map(context => {
+      return this.#getBrowsingContextInfo(context, { maxDepth });
+    });
+
+    return { contexts: contextsInfo };
+  }
+
+  /**
+   * An object that holds the WebDriver Bidi navigation information.
+   *
+   * @typedef BrowsingContextNavigateResult
+   *
+   * @property {String} navigation
+   *     Unique id for this navigation.
+   * @property {String} url
+   *     The requested or reached URL.
+   */
+
+  /**
+   * Navigate the given context to the provided url, with the provided wait condition.
+   *
+   * @param {Object=} options
+   * @param {string} context
+   *     Id of the browsing context to navigate.
+   * @param {string} url
+   *     Url for the navigation.
+   * @param {WaitCondition=} wait
+   *     Wait condition for the navigation, one of "none", "interactive", "complete".
+   *
+   * @returns {BrowsingContextNavigateResult}
+   *     Navigation result.
+   * @throws {InvalidArgumentError}
+   *     Raised if an argument is of an invalid type or value.
+   * @throws {NoSuchFrameError}
+   *     If the browsing context for contextId cannot be found.
+   */
+  async navigate(options = {}) {
+    const { context: contextId, url, wait = WaitCondition.None } = options;
+
+    lazy.assert.string(
+      contextId,
+      `Expected "context" to be a string, got ${contextId}`
+    );
+
+    lazy.assert.string(url, `Expected "url" to be string, got ${url}`);
+
+    const waitConditions = Object.values(WaitCondition);
+    if (!waitConditions.includes(wait)) {
+      throw new lazy.error.InvalidArgumentError(
+        `Expected "wait" to be one of ${waitConditions}, got ${wait}`
+      );
+    }
+
+    const context = this.#getBrowsingContext(contextId);
+
+    // webProgress will be stable even if the context navigates, retrieve it
+    // immediately before doing any asynchronous call.
+    const webProgress = context.webProgress;
+
+    const base = await this.messageHandler.handleCommand({
+      moduleName: "browsingContext",
+      commandName: "_getBaseURL",
+      destination: {
+        type: lazy.WindowGlobalMessageHandler.type,
+        id: context.id,
+      },
+      retryOnAbort: true,
+    });
+
+    let targetURI;
+    try {
+      const baseURI = Services.io.newURI(base);
+      targetURI = Services.io.newURI(url, null, baseURI);
+    } catch (e) {
+      throw new lazy.error.InvalidArgumentError(
+        `Expected "url" to be a valid URL (${e.message})`
+      );
+    }
+
+    return this.#awaitNavigation(webProgress, targetURI, {
+      wait,
+    });
+  }
+
+  /**
+   * Start and await a navigation on the provided BrowsingContext. Returns a
+   * promise which resolves when the navigation is done according to the provided
+   * navigation strategy.
+   *
+   * @param {WebProgress} webProgress
+   *     The WebProgress instance to observe for this navigation.
+   * @param {nsIURI} targetURI
+   *     The URI to navigate to.
+   * @param {Object} options
+   * @param {WaitCondition} options.wait
+   *     The WaitCondition to use to wait for the navigation.
+   */
+  async #awaitNavigation(webProgress, targetURI, options) {
+    const { wait } = options;
+
+    const context = webProgress.browsingContext;
+    const browserId = context.browserId;
+
+    const resolveWhenStarted = wait === WaitCondition.None;
+    const listener = new lazy.ProgressListener(webProgress, {
+      expectNavigation: true,
+      resolveWhenStarted,
+      // In case the webprogress is already navigating, always wait for an
+      // explicit start flag.
+      waitForExplicitStart: true,
+    });
+
+    const onDocumentInteractive = (evtName, wrappedEvt) => {
+      if (webProgress.browsingContext.id !== wrappedEvt.contextId) {
+        // Ignore load events for unrelated browsing contexts.
+        return;
+      }
+
+      if (wrappedEvt.readyState === "interactive") {
+        listener.stopIfStarted();
+      }
+    };
+
+    const contextDescriptor = {
+      type: lazy.ContextDescriptorType.TopBrowsingContext,
+      id: browserId,
+    };
+
+    // For the Interactive wait condition, resolve as soon as
+    // the document becomes interactive.
+    if (wait === WaitCondition.Interactive) {
+      await this.messageHandler.eventsDispatcher.on(
+        "browsingContext._documentInteractive",
+        contextDescriptor,
+        onDocumentInteractive
+      );
+    }
+
+    const navigated = listener.start();
+    navigated.finally(async () => {
+      if (listener.isStarted) {
+        listener.stop();
+      }
+
+      if (wait === WaitCondition.Interactive) {
+        await this.messageHandler.eventsDispatcher.off(
+          "browsingContext._documentInteractive",
+          contextDescriptor,
+          onDocumentInteractive
+        );
+      }
+    });
+
+    context.loadURI(targetURI.spec, {
+      loadFlags: Ci.nsIWebNavigation.LOAD_FLAGS_IS_LINK,
+      triggeringPrincipal: Services.scriptSecurityManager.getSystemPrincipal(),
+      hasValidUserGestureActivation: true,
+    });
+    await navigated;
+
+    let url;
+    if (wait === WaitCondition.None) {
+      // If wait condition is None, the navigation resolved before the current
+      // context has navigated.
+      url = listener.targetURI.spec;
+    } else {
+      url = listener.currentURI.spec;
+    }
+
+    return {
+      // TODO: The navigation id should be a real id mapped to the navigation.
+      // See https://bugzilla.mozilla.org/show_bug.cgi?id=1763122
+      navigation: null,
+      url,
+    };
+  }
+
+  /**
+   * Retrieves a browsing context based on its id.
+   *
+   * @param {Number} contextId
+   *     Id of the browsing context.
+   * @returns {BrowsingContext=}
+   *     The browsing context or null if <var>contextId</var> is null.
+   * @throws {NoSuchFrameError}
+   *     If the browsing context cannot be found.
+   */
+  #getBrowsingContext(contextId) {
+    // The WebDriver BiDi specification expects null to be
+    // returned if no browsing context id has been specified.
+    if (contextId === null) {
+      return null;
+    }
+
+    const context = lazy.TabManager.getBrowsingContextById(contextId);
+    if (context === null) {
+      throw new lazy.error.NoSuchFrameError(
+        `Browsing Context with id ${contextId} not found`
+      );
+    }
+
+    return context;
+  }
+
+  /**
+   * Get the WebDriver BiDi browsing context information.
+   *
+   * @param {BrowsingContext} context
+   *     The browsing context to get the information from.
+   * @param {Object=} options
+   * @param {boolean=} isRoot
+   *     Flag that indicates if this browsing context is the root of all the
+   *     browsing contexts to be returned. Defaults to true.
+   * @param {number=} maxDepth
+   *     Depth of the browsing context tree to traverse. If not specified
+   *     the whole tree is returned.
+   * @returns {BrowsingContextInfo}
+   *     The information about the browsing context.
+   */
+  #getBrowsingContextInfo(context, options = {}) {
+    const { isRoot = true, maxDepth = null } = options;
+
+    let children = null;
+    if (maxDepth === null || maxDepth > 0) {
+      children = context.children.map(context =>
+        this.#getBrowsingContextInfo(context, {
+          maxDepth: maxDepth === null ? maxDepth : maxDepth - 1,
+          isRoot: false,
+        })
+      );
+    }
+
+    const contextInfo = {
+      context: lazy.TabManager.getIdForBrowsingContext(context),
+      url: context.currentURI.spec,
+      children,
+    };
+
+    if (isRoot) {
+      // Only emit the parent id for the top-most browsing context.
+      const parentId = lazy.TabManager.getIdForBrowsingContext(context.parent);
+      contextInfo.parent = parentId;
+    }
+
+    return contextInfo;
+  }
+
+  #onContextAttached = async (eventName, data = {}) => {
+    const { browsingContext, why } = data;
+
+    // Filter out top-level browsing contexts that are created because of a
+    // cross-group navigation.
+    if (why === "replace") {
+      return;
+    }
+
+    // Filter out notifications for chrome context until support gets
+    // added (bug 1722679).
+    if (!browsingContext.webProgress) {
+      return;
+    }
+
+    const browsingContextInfo = this.#getBrowsingContextInfo(browsingContext, {
+      maxDepth: 0,
+    });
+
+    // This event is emitted from the parent process but for a given browsing
+    // context. Set the event's contextInfo to the message handler corresponding
+    // to this browsing context.
+    const contextInfo = {
+      contextId: browsingContext.id,
+      type: lazy.WindowGlobalMessageHandler.type,
+    };
+    this.emitEvent(
+      "browsingContext.contextCreated",
+      browsingContextInfo,
+      contextInfo
+    );
+  };
+
+  #subscribeEvent(event) {
+    if (event === "browsingContext.contextCreated") {
+      this.#contextListener.startListening();
+      this.#subscribedEvents.add(event);
+    }
+  }
+
+  #unsubscribeEvent(event) {
+    if (event === "browsingContext.contextCreated") {
+      this.#contextListener.stopListening();
+      this.#subscribedEvents.delete(event);
+    }
+  }
+
+  /**
+   * Internal commands
+   */
+
+  _applySessionData(params) {
+    // TODO: Bug 1775231. Move this logic to a shared module or an abstract
+    // class.
+    const { category } = params;
+    if (category === "event") {
+      const filteredSessionData = params.sessionData.filter(item =>
+        this.messageHandler.matchesContext(item.contextDescriptor)
+      );
+      for (const event of this.#subscribedEvents.values()) {
+        const hasSessionItem = filteredSessionData.some(
+          item => item.value === event
+        );
+        // If there are no session items for this context, we should unsubscribe from the event.
+        if (!hasSessionItem) {
+          this.#unsubscribeEvent(event);
+        }
+      }
+
+      // Subscribe to all events, which have an item in SessionData.
+      for (const { value } of filteredSessionData) {
+        this.#subscribeEvent(value);
+      }
+    }
+  }
+
+  static get supportedEvents() {
+    return [
+      "browsingContext.contextCreated",
+      "browsingContext.domContentLoaded",
+      "browsingContext.load",
+    ];
+  }
+}
+
+export const browsingContext = BrowsingContextModule;
diff --git a/remote/webdriver-bidi/modules/root/log.sys.mjs b/remote/webdriver-bidi/modules/root/log.sys.mjs
new file mode 100644
index 0000000000..db2390d3ba
--- /dev/null
+++ b/remote/webdriver-bidi/modules/root/log.sys.mjs
@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import { Module } from "chrome://remote/content/shared/messagehandler/Module.sys.mjs";
+
+class LogModule extends Module {
+  destroy() {}
+
+  static get supportedEvents() {
+    return ["log.entryAdded"];
+  }
+}
+
+export const log = LogModule;
diff --git a/remote/webdriver-bidi/modules/root/network.sys.mjs b/remote/webdriver-bidi/modules/root/network.sys.mjs
new file mode 100644
index 0000000000..e82bc3c072
--- /dev/null
+++ b/remote/webdriver-bidi/modules/root/network.sys.mjs
@@ -0,0 +1,342 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import { Module } from "chrome://remote/content/shared/messagehandler/Module.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  error: "chrome://remote/content/shared/webdriver/Errors.sys.mjs",
+  NetworkListener:
+    "chrome://remote/content/shared/listeners/NetworkListener.sys.mjs",
+  TabManager: "chrome://remote/content/shared/TabManager.sys.mjs",
+  WindowGlobalMessageHandler:
+    "chrome://remote/content/shared/messagehandler/WindowGlobalMessageHandler.sys.mjs",
+});
+
+/**
+ * @typedef {Object} BaseParameters
+ * @property {string=} context
+ * @property {boolean} isRedirect
+ * @property {Navigation=} navigation
+ * @property {RequestData} request
+ * @property {number} timestamp
+ */
+
+/**
+ * @typedef {Object} Cookie
+ * @property {Array<number>=} binaryValue
+ * @property {string} domain
+ * @property {number=} expires
+ * @property {boolean} httpOnly
+ * @property {string} name
+ * @property {string} path
+ * @property {('lax' | 'none' | 'strict')} sameSite
+ * @property {boolean} secure
+ * @property {number} size
+ * @property {string=} value
+ */
+
+/**
+ * @typedef {Object} FetchTimingInfo
+ * @property {number} originTime
+ * @property {number} requestTime
+ * @property {number} redirectStart
+ * @property {number} redirectEnd
+ * @property {number} fetchStart
+ * @property {number} dnsStart
+ * @property {number} dnsEnd
+ * @property {number} connectStart
+ * @property {number} connectEnd
+ * @property {number} tlsStart
+ * @property {number} requestStart
+ * @property {number} responseStart
+ * @property {number} responseEnd
+ */
+
+/**
+ * @typedef {Object} Header
+ * @property {Array<number>=} binaryValue
+ * @property {string} name
+ * @property {string=} value
+ */
+
+/**
+ * @typedef {string} InitiatorType
+ **/
+
+/**
+ * Enum of possible initiator types.
+ *
+ * @readonly
+ * @enum {InitiatorType}
+ **/
+const InitiatorType = {
+  Other: "other",
+  Parser: "parser",
+  Preflight: "preflight",
+  Script: "script",
+};
+/**
+ * @typedef {Object} Initiator
+ * @property {InitiatorType} type
+ * @property {number=} columnNumber
+ * @property {number=} lineNumber
+ * @property {string=} request
+ * @property {StackTrace=} stackTrace
+ */
+
+/**
+ * @typedef {Object} RequestData
+ * @property {number|null} bodySize
+ *     Defaults to null.
+ * @property {Array<Cookie>} cookies
+ * @property {Array<Header>} headers
+ * @property {number} headersSize
+ * @property {string} method
+ * @property {string} request
+ * @property {FetchTimingInfo} timings
+ * @property {string} url
+ */
+
+/**
+ * @typedef {Object} BeforeRequestSentParametersProperties
+ * @property {Initiator} initiator
+ */
+
+/**
+ * Parameters for the BeforeRequestSent event
+ *
+ * @typedef {BaseParameters & BeforeRequestSentParametersProperties} BeforeRequestSentParameters
+ */
+
+/**
+ * @typedef {Object} ResponseContent
+ * @property {number|null} size
+ *     Defaults to null.
+ */
+
+/**
+ * @typedef {Object} ResponseData
+ * @property {string} url
+ * @property {string} protocol
+ * @property {number} status
+ * @property {string} statusText
+ * @property {boolean} fromCache
+ * @property {Array<Header>} headers
+ * @property {string} mimeType
+ * @property {number} bytesReceived
+ * @property {number|null} headersSize
+ *     Defaults to null.
+ * @property {number|null} bodySize
+ *     Defaults to null.
+ * @property {ResponseContent} content
+ */
+
+/**
+ * @typedef {Object} ResponseStartedParametersProperties
+ * @property {ResponseData} response
+ */
+
+/**
+ * Parameters for the ResponseStarted event
+ *
+ * @typedef {BaseParameters & ResponseStartedParametersProperties} ResponseStartedParameters
+ */
+
+/**
+ * @typedef {Object} ResponseCompletedParametersProperties
+ * @property {ResponseData} response
+ */
+
+/**
+ * Parameters for the ResponseCompleted event
+ *
+ * @typedef {BaseParameters & ResponseCompletedParametersProperties} ResponseCompletedParameters
+ */
+
+class NetworkModule extends Module {
+  #beforeRequestSentMap;
+  #networkListener;
+  #subscribedEvents;
+
+  constructor(messageHandler) {
+    super(messageHandler);
+
+    // Map of request ids to redirect counts. A WebDriver BiDi request id is
+    // identical for redirects of a given request, this map allows to know if we
+    // already emitted a beforeRequestSent event for a given request with a
+    // specific redirectCount.
+    this.#beforeRequestSentMap = new Map();
+
+    // Set of event names which have active subscriptions
+    this.#subscribedEvents = new Set();
+
+    this.#networkListener = new lazy.NetworkListener();
+    this.#networkListener.on("before-request-sent", this.#onBeforeRequestSent);
+    this.#networkListener.on("response-completed", this.#onResponseEvent);
+    this.#networkListener.on("response-started", this.#onResponseEvent);
+  }
+
+  destroy() {
+    this.#networkListener.off("before-request-sent", this.#onBeforeRequestSent);
+    this.#networkListener.off("response-completed", this.#onResponseEvent);
+    this.#networkListener.off("response-started", this.#onResponseEvent);
+
+    this.#beforeRequestSentMap = null;
+    this.#subscribedEvents = null;
+  }
+
+  #getContextInfo(browsingContext) {
+    return {
+      contextId: browsingContext.id,
+      type: lazy.WindowGlobalMessageHandler.type,
+    };
+  }
+
+  #onBeforeRequestSent = (name, data) => {
+    const { contextId, requestData, timestamp, redirectCount } = data;
+
+    const isRedirect = redirectCount > 0;
+    this.#beforeRequestSentMap.set(requestData.requestId, redirectCount);
+
+    // Bug 1805479: Handle the initiator, including stacktrace details.
+    const initiator = {
+      type: InitiatorType.Other,
+    };
+
+    const baseParameters = {
+      context: contextId,
+      isRedirect,
+      redirectCount,
+      // Bug 1805405: Handle the navigation id.
+      navigation: null,
+      request: requestData,
+      timestamp,
+    };
+
+    const beforeRequestSentEvent = {
+      ...baseParameters,
+      initiator,
+    };
+
+    const browsingContext = lazy.TabManager.getBrowsingContextById(contextId);
+    this.emitEvent(
+      "network.beforeRequestSent",
+      beforeRequestSentEvent,
+      this.#getContextInfo(browsingContext)
+    );
+  };
+
+  #onResponseEvent = (name, data) => {
+    const {
+      contextId,
+      requestData,
+      responseData,
+      timestamp,
+      redirectCount,
+    } = data;
+
+    const isRedirect = redirectCount > 0;
+
+    const requestId = requestData.requestId;
+    if (this.#beforeRequestSentMap.get(requestId) != redirectCount) {
+      throw new lazy.error.UnknownError(
+        `Redirect count of the request ${requestId} does not match the before request sent map`
+      );
+    }
+
+    const baseParameters = {
+      context: contextId,
+      isRedirect,
+      redirectCount,
+      // Bug 1805405: Handle the navigation id.
+      navigation: null,
+      request: requestData,
+      timestamp,
+    };
+
+    const responseEvent = {
+      ...baseParameters,
+      response: responseData,
+    };
+
+    const protocolEventName =
+      name === "response-started"
+        ? "network.responseStarted"
+        : "network.responseCompleted";
+
+    const browsingContext = lazy.TabManager.getBrowsingContextById(contextId);
+    this.emitEvent(
+      protocolEventName,
+      responseEvent,
+      this.#getContextInfo(browsingContext)
+    );
+  };
+
+  #startListening(event) {
+    if (this.#subscribedEvents.size == 0) {
+      this.#networkListener.startListening();
+    }
+    this.#subscribedEvents.add(event);
+  }
+
+  #stopListening(event) {
+    this.#subscribedEvents.delete(event);
+    if (this.#subscribedEvents.size == 0) {
+      this.#networkListener.stopListening();
+    }
+  }
+
+  #subscribeEvent(event) {
+    if (this.constructor.supportedEvents.includes(event)) {
+      this.#startListening(event);
+    }
+  }
+
+  #unsubscribeEvent(event) {
+    if (this.constructor.supportedEvents.includes(event)) {
+      this.#stopListening(event);
+    }
+  }
+
+  /**
+   * Internal commands
+   */
+
+  _applySessionData(params) {
+    // TODO: Bug 1775231. Move this logic to a shared module or an abstract
+    // class.
+    const { category } = params;
+    if (category === "event") {
+      const filteredSessionData = params.sessionData.filter(item =>
+        this.messageHandler.matchesContext(item.contextDescriptor)
+      );
+      for (const event of this.#subscribedEvents.values()) {
+        const hasSessionItem = filteredSessionData.some(
+          item => item.value === event
+        );
+        // If there are no session items for this context, we should unsubscribe from the event.
+        if (!hasSessionItem) {
+          this.#unsubscribeEvent(event);
+        }
+      }
+
+      // Subscribe to all events, which have an item in SessionData.
+      for (const { value } of filteredSessionData) {
+        this.#subscribeEvent(value);
+      }
+    }
+  }
+
+  static get supportedEvents() {
+    return [
+      "network.beforeRequestSent",
+      "network.responseCompleted",
+      "network.responseStarted",
+    ];
+  }
+}
+
+export const network = NetworkModule;
diff --git a/remote/webdriver-bidi/modules/root/script.sys.mjs b/remote/webdriver-bidi/modules/root/script.sys.mjs
new file mode 100644
index 0000000000..308033c816
--- /dev/null
+++ b/remote/webdriver-bidi/modules/root/script.sys.mjs
@@ -0,0 +1,532 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import { Module } from "chrome://remote/content/shared/messagehandler/Module.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  assert: "chrome://remote/content/shared/webdriver/Assert.sys.mjs",
+  ContextDescriptorType:
+    "chrome://remote/content/shared/messagehandler/MessageHandler.sys.mjs",
+  error: "chrome://remote/content/shared/webdriver/Errors.sys.mjs",
+  OwnershipModel: "chrome://remote/content/webdriver-bidi/RemoteValue.sys.mjs",
+  RealmType: "chrome://remote/content/webdriver-bidi/Realm.sys.mjs",
+  TabManager: "chrome://remote/content/shared/TabManager.sys.mjs",
+  WindowGlobalMessageHandler:
+    "chrome://remote/content/shared/messagehandler/WindowGlobalMessageHandler.sys.mjs",
+});
+
+/**
+ * @typedef {string} ScriptEvaluateResultType
+ **/
+
+/**
+ * Enum of possible evaluation result types.
+ *
+ * @readonly
+ * @enum {ScriptEvaluateResultType}
+ **/
+const ScriptEvaluateResultType = {
+  Exception: "exception",
+  Success: "success",
+};
+
+class ScriptModule extends Module {
+  destroy() {}
+
+  /**
+   * Used to represent a frame of a JavaScript stack trace.
+   *
+   * @typedef StackFrame
+   *
+   * @property {number} columnNumber
+   * @property {string} functionName
+   * @property {number} lineNumber
+   * @property {string} url
+   */
+
+  /**
+   * Used to represent a JavaScript stack at a point in script execution.
+   *
+   * @typedef StackTrace
+   *
+   * @property {Array<StackFrame>} callFrames
+   */
+
+  /**
+   * Used to represent a JavaScript exception.
+   *
+   * @typedef ExceptionDetails
+   *
+   * @property {number} columnNumber
+   * @property {RemoteValue} exception
+   * @property {number} lineNumber
+   * @property {StackTrace} stackTrace
+   * @property {string} text
+   */
+
+  /**
+   * Used as return value for script.evaluate, as one of the available variants
+   * {ScriptEvaluateResultException} or {ScriptEvaluateResultSuccess}.
+   *
+   * @typedef ScriptEvaluateResult
+   */
+
+  /**
+   * Used as return value for script.evaluate when the script completes with a
+   * thrown exception.
+   *
+   * @typedef ScriptEvaluateResultException
+   *
+   * @property {ExceptionDetails} exceptionDetails
+   * @property {string} realm
+   * @property {ScriptEvaluateResultType} [type=ScriptEvaluateResultType.Exception]
+   */
+
+  /**
+   * Used as return value for script.evaluate when the script completes
+   * normally.
+   *
+   * @typedef ScriptEvaluateResultSuccess
+   *
+   * @property {string} realm
+   * @property {RemoteValue} result
+   * @property {ScriptEvaluateResultType} [type=ScriptEvaluateResultType.Success]
+   */
+
+  /**
+   * Calls a provided function with given arguments and scope in the provided
+   * target, which is either a realm or a browsing context.
+   *
+   * @param {Object=} options
+   * @param {Array<RemoteValue>=} arguments
+   *     The arguments to pass to the function call.
+   * @param {boolean} awaitPromise
+   *     Determines if the command should wait for the return value of the
+   *     expression to resolve, if this return value is a Promise.
+   * @param {string} functionDeclaration
+   *     The expression to evaluate.
+   * @param {OwnershipModel=} resultOwnership
+   *     The ownership model to use for the results of this evaluation. Defaults
+   *     to `OwnershipModel.None`.
+   * @param {Object} target
+   *     The target for the evaluation, which either matches the definition for
+   *     a RealmTarget or for ContextTarget.
+   * @param {RemoteValue=} this
+   *     The value of the this keyword for the function call.
+   *
+   * @returns {ScriptEvaluateResult}
+   *
+   * @throws {InvalidArgumentError}
+   *     If any of the arguments does not have the expected type.
+   * @throws {NoSuchFrameError}
+   *     If the target cannot be found.
+   */
+  async callFunction(options = {}) {
+    const {
+      arguments: commandArguments = null,
+      awaitPromise,
+      functionDeclaration,
+      resultOwnership = lazy.OwnershipModel.None,
+      target = {},
+      this: thisParameter = null,
+    } = options;
+
+    lazy.assert.string(
+      functionDeclaration,
+      `Expected "functionDeclaration" to be a string, got ${functionDeclaration}`
+    );
+
+    lazy.assert.boolean(
+      awaitPromise,
+      `Expected "awaitPromise" to be a boolean, got ${awaitPromise}`
+    );
+
+    this.#assertResultOwnership(resultOwnership);
+
+    if (commandArguments != null) {
+      lazy.assert.array(
+        commandArguments,
+        `Expected "arguments" to be an array, got ${commandArguments}`
+      );
+    }
+
+    const { contextId, realmId, sandbox } = this.#assertTarget(target);
+    const context = await this.#getContextFromTarget({ contextId, realmId });
+    const evaluationResult = await this.messageHandler.forwardCommand({
+      moduleName: "script",
+      commandName: "callFunctionDeclaration",
+      destination: {
+        type: lazy.WindowGlobalMessageHandler.type,
+        id: context.id,
+      },
+      params: {
+        awaitPromise,
+        commandArguments,
+        functionDeclaration,
+        realmId,
+        resultOwnership,
+        sandbox,
+        thisParameter,
+      },
+    });
+
+    return this.#buildReturnValue(evaluationResult);
+  }
+
+  /**
+   * The script.disown command disowns the given handles. This does not
+   * guarantee the handled object will be garbage collected, as there can be
+   * other handles or strong ECMAScript references.
+   *
+   * @param {Object=} options
+   * @param {Array<string>} handles
+   *     Array of handle ids to disown.
+   * @param {Object} target
+   *     The target owning the handles, which either matches the definition for
+   *     a RealmTarget or for ContextTarget.
+   */
+  async disown(options = {}) {
+    const { handles, target = {} } = options;
+
+    lazy.assert.array(
+      handles,
+      `Expected "handles" to be an array, got ${handles}`
+    );
+    handles.forEach(handle => {
+      lazy.assert.string(
+        handle,
+        `Expected "handles" to be an array of strings, got ${handle}`
+      );
+    });
+
+    const { contextId, realmId, sandbox } = this.#assertTarget(target);
+    const context = await this.#getContextFromTarget({ contextId, realmId });
+    await this.messageHandler.forwardCommand({
+      moduleName: "script",
+      commandName: "disownHandles",
+      destination: {
+        type: lazy.WindowGlobalMessageHandler.type,
+        id: context.id,
+      },
+      params: {
+        handles,
+        realmId,
+        sandbox,
+      },
+    });
+  }
+
+  /**
+   * Evaluate a provided expression in the provided target, which is either a
+   * realm or a browsing context.
+   *
+   * @param {Object=} options
+   * @param {boolean} awaitPromise
+   *     Determines if the command should wait for the return value of the
+   *     expression to resolve, if this return value is a Promise.
+   * @param {string} expression
+   *     The expression to evaluate.
+   * @param {OwnershipModel=} resultOwnership
+   *     The ownership model to use for the results of this evaluation. Defaults
+   *     to `OwnershipModel.None`.
+   * @param {Object} target
+   *     The target for the evaluation, which either matches the definition for
+   *     a RealmTarget or for ContextTarget.
+   *
+   * @returns {ScriptEvaluateResult}
+   *
+   * @throws {InvalidArgumentError}
+   *     If any of the arguments does not have the expected type.
+   * @throws {NoSuchFrameError}
+   *     If the target cannot be found.
+   */
+  async evaluate(options = {}) {
+    const {
+      awaitPromise,
+      expression: source,
+      resultOwnership = lazy.OwnershipModel.None,
+      target = {},
+    } = options;
+
+    lazy.assert.string(
+      source,
+      `Expected "expression" to be a string, got ${source}`
+    );
+
+    lazy.assert.boolean(
+      awaitPromise,
+      `Expected "awaitPromise" to be a boolean, got ${awaitPromise}`
+    );
+
+    this.#assertResultOwnership(resultOwnership);
+
+    const { contextId, realmId, sandbox } = this.#assertTarget(target);
+    const context = await this.#getContextFromTarget({ contextId, realmId });
+    const evaluationResult = await this.messageHandler.forwardCommand({
+      moduleName: "script",
+      commandName: "evaluateExpression",
+      destination: {
+        type: lazy.WindowGlobalMessageHandler.type,
+        id: context.id,
+      },
+      params: {
+        awaitPromise,
+        expression: source,
+        realmId,
+        resultOwnership,
+        sandbox,
+      },
+    });
+
+    return this.#buildReturnValue(evaluationResult);
+  }
+
+  /**
+   * An object that holds basic information about a realm.
+   *
+   * @typedef BaseRealmInfo
+   *
+   * @property {string} id
+   *     The realm unique identifier.
+   * @property {string} origin
+   *     The serialization of an origin.
+   */
+
+  /**
+   *
+   * @typedef WindowRealmInfoProperties
+   *
+   * @property {string} context
+   *     The browsing context id, associated with the realm.
+   * @property {string=} sandbox
+   *     The name of the sandbox. If the value is null or empty
+   *     string, the default realm will be returned.
+   * @property {RealmType.Window} type
+   *     The window realm type.
+   */
+
+  /**
+   * An object that holds information about a window realm.
+   *
+   * @typedef {BaseRealmInfo & WindowRealmInfoProperties} WindowRealmInfo
+   */
+
+  /**
+   * An object that holds information about a realm.
+   *
+   * @typedef {WindowRealmInfo} RealmInfo
+   */
+
+  /**
+   * An object that holds a list of realms.
+   *
+   * @typedef ScriptGetRealmsResult
+   *
+   * @property {Array<RealmInfo>} realms
+   *     List of realms.
+   */
+
+  /**
+   * Returns a list of all realms, optionally filtered to realms
+   * of a specific type, or to the realms associated with
+   * a specified browsing context.
+   *
+   * @param {Object=} options
+   * @param {string=} context
+   *     The id of the browsing context to filter
+   *     only realms associated with it. If not provided, return realms
+   *     associated with all browsing contexts.
+   * @param {RealmType=} type
+   *     Type of realm to filter.
+   *     If not provided, return realms of all types.
+   *
+   * @returns {ScriptGetRealmsResult}
+   *
+   * @throws {InvalidArgumentError}
+   *     If any of the arguments does not have the expected type.
+   * @throws {NoSuchFrameError}
+   *     If the context cannot be found.
+   */
+  async getRealms(options = {}) {
+    const { context: contextId = null, type = null } = options;
+    const destination = {};
+
+    if (contextId !== null) {
+      lazy.assert.string(
+        contextId,
+        `Expected "context" to be a string, got ${contextId}`
+      );
+      destination.id = this.#getBrowsingContext(contextId).id;
+    } else {
+      destination.contextDescriptor = {
+        type: lazy.ContextDescriptorType.All,
+      };
+    }
+
+    if (type !== null) {
+      const supportedRealmTypes = Object.values(lazy.RealmType);
+      if (!supportedRealmTypes.includes(type)) {
+        throw new lazy.error.InvalidArgumentError(
+          `Expected "type" to be one of ${supportedRealmTypes}, got ${type}`
+        );
+      }
+
+      // Remove this check when other realm types are supported
+      if (type !== lazy.RealmType.Window) {
+        throw new lazy.error.UnsupportedOperationError(
+          `Unsupported "type": ${type}. Only "type" ${lazy.RealmType.Window} is currently supported.`
+        );
+      }
+    }
+
+    return { realms: await this.#getRealmInfos(destination) };
+  }
+
+  #assertResultOwnership(resultOwnership) {
+    if (
+      ![lazy.OwnershipModel.None, lazy.OwnershipModel.Root].includes(
+        resultOwnership
+      )
+    ) {
+      throw new lazy.error.InvalidArgumentError(
+        `Expected "resultOwnership" to be one of ${Object.values(
+          lazy.OwnershipModel
+        )}, got ${resultOwnership}`
+      );
+    }
+  }
+
+  #assertTarget(target) {
+    lazy.assert.object(
+      target,
+      `Expected "target" to be an object, got ${target}`
+    );
+
+    const {
+      context: contextId = null,
+      realm: realmId = null,
+      sandbox = null,
+    } = target;
+
+    if (realmId != null && (contextId != null || sandbox != null)) {
+      throw new lazy.error.InvalidArgumentError(
+        `A context and a realm reference are mutually exclusive`
+      );
+    }
+
+    if (contextId != null) {
+      lazy.assert.string(
+        contextId,
+        `Expected "context" to be a string, got ${contextId}`
+      );
+
+      if (sandbox != null) {
+        lazy.assert.string(
+          sandbox,
+          `Expected "sandbox" to be a string, got ${sandbox}`
+        );
+      }
+    } else if (realmId != null) {
+      lazy.assert.string(
+        realmId,
+        `Expected "realm" to be a string, got ${realmId}`
+      );
+    } else {
+      throw new lazy.error.InvalidArgumentError(`No context or realm provided`);
+    }
+
+    return { contextId, realmId, sandbox };
+  }
+
+  #buildReturnValue(evaluationResult) {
+    const rv = { realm: evaluationResult.realmId };
+    switch (evaluationResult.evaluationStatus) {
+      // TODO: Compare with EvaluationStatus.Normal after Bug 1774444 is fixed.
+      case "normal":
+        rv.type = ScriptEvaluateResultType.Success;
+        rv.result = evaluationResult.result;
+        break;
+      // TODO: Compare with EvaluationStatus.Throw after Bug 1774444 is fixed.
+      case "throw":
+        rv.type = ScriptEvaluateResultType.Exception;
+        rv.exceptionDetails = evaluationResult.exceptionDetails;
+        break;
+      default:
+        throw new lazy.error.UnsupportedOperationError(
+          `Unsupported evaluation status ${evaluationResult.evaluationStatus}`
+        );
+    }
+    return rv;
+  }
+
+  #getBrowsingContext(contextId) {
+    const context = lazy.TabManager.getBrowsingContextById(contextId);
+    if (context === null) {
+      throw new lazy.error.NoSuchFrameError(
+        `Browsing Context with id ${contextId} not found`
+      );
+    }
+
+    if (!context.currentWindowGlobal) {
+      throw new lazy.error.NoSuchFrameError(
+        `No window found for BrowsingContext with id ${contextId}`
+      );
+    }
+
+    return context;
+  }
+
+  async #getContextFromTarget({ contextId, realmId }) {
+    if (contextId !== null) {
+      return this.#getBrowsingContext(contextId);
+    }
+
+    const destination = {
+      contextDescriptor: {
+        type: lazy.ContextDescriptorType.All,
+      },
+    };
+    const realms = await this.#getRealmInfos(destination);
+    const realm = realms.find(realm => realm.realm == realmId);
+
+    if (realm && realm.context !== null) {
+      return this.#getBrowsingContext(realm.context);
+    }
+
+    throw new lazy.error.NoSuchFrameError(`Realm with id ${realmId} not found`);
+  }
+
+  async #getRealmInfos(destination) {
+    let realms = await this.messageHandler.forwardCommand({
+      moduleName: "script",
+      commandName: "getWindowRealms",
+      destination: {
+        type: lazy.WindowGlobalMessageHandler.type,
+        ...destination,
+      },
+    });
+
+    const isBroadcast = !!destination.contextDescriptor;
+    if (!isBroadcast) {
+      realms = [realms];
+    }
+
+    return realms
+      .flat()
+      .map(realm => {
+        // Resolve browsing context to a TabManager id.
+        realm.context = lazy.TabManager.getIdForBrowsingContext(realm.context);
+        return realm;
+      })
+      .filter(realm => realm.context !== null);
+  }
+
+  static get supportedEvents() {
+    return [];
+  }
+}
+
+export const script = ScriptModule;
diff --git a/remote/webdriver-bidi/modules/root/session.sys.mjs b/remote/webdriver-bidi/modules/root/session.sys.mjs
new file mode 100644
index 0000000000..281b913f32
--- /dev/null
+++ b/remote/webdriver-bidi/modules/root/session.sys.mjs
@@ -0,0 +1,406 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import { Module } from "chrome://remote/content/shared/messagehandler/Module.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  assert: "chrome://remote/content/shared/webdriver/Assert.sys.mjs",
+  ContextDescriptorType:
+    "chrome://remote/content/shared/messagehandler/MessageHandler.sys.mjs",
+  error: "chrome://remote/content/shared/webdriver/Errors.sys.mjs",
+  RootMessageHandler:
+    "chrome://remote/content/shared/messagehandler/RootMessageHandler.sys.mjs",
+  TabManager: "chrome://remote/content/shared/TabManager.sys.mjs",
+});
+
+class SessionModule extends Module {
+  #browsingContextIdEventMap;
+  #globalEventSet;
+
+  constructor(messageHandler) {
+    super(messageHandler);
+
+    // Map with top-level browsing context id keys and values
+    // that are a set of event names for events
+    // that are enabled in the given browsing context.
+    // TODO: Bug 1804417. Use navigable instead of browsing context id.
+    this.#browsingContextIdEventMap = new Map();
+
+    // Set of event names which are strings of the form [moduleName].[eventName]
+    // for events that are enabled for all browsing contexts.
+    // We should only add an actual event listener on the MessageHandler the
+    // first time an event is subscribed to.
+    this.#globalEventSet = new Set();
+  }
+
+  destroy() {
+    this.#browsingContextIdEventMap = null;
+    this.#globalEventSet = null;
+  }
+
+  /**
+   * Commands
+   */
+
+  /**
+   * Enable certain events either globally, or for a list of browsing contexts.
+   *
+   * @params {Object=} params
+   * @params {Array<string>} events
+   *     List of events to subscribe to.
+   * @params {Array<string>=} contexts
+   *     Optional list of top-level browsing context ids
+   *     to subscribe the events for.
+   *
+   * @throws {InvalidArgumentError}
+   *     If <var>events</var> or <var>contexts</var> are not valid types.
+   */
+  async subscribe(params = {}) {
+    const { events, contexts: contextIds = null } = params;
+
+    // Check input types until we run schema validation.
+    lazy.assert.array(events, "events: array value expected");
+    events.forEach(name => {
+      lazy.assert.string(name, `${name}: string value expected`);
+    });
+
+    if (contextIds !== null) {
+      lazy.assert.array(contextIds, "contexts: array value expected");
+      contextIds.forEach(contextId => {
+        lazy.assert.string(contextId, `${contextId}: string value expected`);
+      });
+    }
+
+    const listeners = this.#updateEventMap(events, contextIds, true);
+
+    // TODO: Bug 1801284. Add subscribe priority sorting of subscribeStepEvents (step 4 to 6, and 8).
+
+    // Subscribe to the relevant engine-internal events.
+    await this.messageHandler.eventsDispatcher.update(listeners);
+  }
+
+  /**
+   * Disable certain events either globally, or for a list of browsing contexts.
+   *
+   * @params {Object=} params
+   * @params {Array<string>} events
+   *     List of events to unsubscribe from.
+   * @params {Array<string>=} contexts
+   *     Optional list of top-level browsing context ids
+   *     to unsubscribe the events from.
+   *
+   * @throws {InvalidArgumentError}
+   *     If <var>events</var> or <var>contexts</var> are not valid types.
+   */
+  async unsubscribe(params = {}) {
+    const { events, contexts: contextIds = null } = params;
+
+    // Check input types until we run schema validation.
+    lazy.assert.array(events, "events: array value expected");
+    events.forEach(name => {
+      lazy.assert.string(name, `${name}: string value expected`);
+    });
+    if (contextIds !== null) {
+      lazy.assert.array(contextIds, "contexts: array value expected");
+      contextIds.forEach(contextId => {
+        lazy.assert.string(contextId, `${contextId}: string value expected`);
+      });
+    }
+
+    const listeners = this.#updateEventMap(events, contextIds, false);
+
+    // Unsubscribe from the relevant engine-internal events.
+    await this.messageHandler.eventsDispatcher.update(listeners);
+  }
+
+  #assertModuleSupportsEvent(moduleName, event) {
+    const rootModuleClass = this.#getRootModuleClass(moduleName);
+    if (!rootModuleClass?.supportsEvent(event)) {
+      throw new lazy.error.InvalidArgumentError(
+        `${event} is not a valid event name`
+      );
+    }
+  }
+
+  #getBrowserIdForContextId(contextId) {
+    const context = lazy.TabManager.getBrowsingContextById(contextId);
+    if (!context) {
+      throw new lazy.error.NoSuchFrameError(
+        `Browsing context with id ${contextId} not found`
+      );
+    }
+
+    return context.browserId;
+  }
+
+  #getRootModuleClass(moduleName) {
+    // Modules which support event subscriptions should have a root module
+    // defining supported events.
+    const rootDestination = { type: lazy.RootMessageHandler.type };
+    const moduleClasses = this.messageHandler.getAllModuleClasses(
+      moduleName,
+      rootDestination
+    );
+
+    if (!moduleClasses.length) {
+      throw new lazy.error.InvalidArgumentError(
+        `Module ${moduleName} does not exist`
+      );
+    }
+
+    return moduleClasses[0];
+  }
+
+  #getTopBrowsingContextId(contextId) {
+    const context = lazy.TabManager.getBrowsingContextById(contextId);
+    if (!context) {
+      throw new lazy.error.NoSuchFrameError(
+        `Browsing context with id ${contextId} not found`
+      );
+    }
+    const topContext = context.top;
+    return lazy.TabManager.getIdForBrowsingContext(topContext);
+  }
+
+  /**
+   * Obtain a set of events based on the given event name.
+   *
+   * Could contain a period for a specific event,
+   * or just the module name for all events.
+   *
+   * @param {string} event
+   *     Name of the event to process.
+   *
+   * @returns {Set<string>}
+   *     A Set with the expanded events in the form of `<module>.<event>`.
+   *
+   * @throws {InvalidArgumentError}
+   *     If <var>event</var> does not reference a valid event.
+   */
+  #obtainEvents(event) {
+    const events = new Set();
+
+    // Check if a period is present that splits the event name into the module,
+    // and the actual event. Hereby only care about the first found instance.
+    const index = event.indexOf(".");
+    if (index >= 0) {
+      const [moduleName] = event.split(".");
+      this.#assertModuleSupportsEvent(moduleName, event);
+      events.add(event);
+    } else {
+      // Interpret the name as module, and register all its available events
+      const rootModuleClass = this.#getRootModuleClass(event);
+      const supportedEvents = rootModuleClass?.supportedEvents;
+
+      for (const eventName of supportedEvents) {
+        events.add(eventName);
+      }
+    }
+
+    return events;
+  }
+
+  /**
+   * Obtain a list of event enabled browsing context ids.
+   *
+   * @see https://w3c.github.io/webdriver-bidi/#event-enabled-browsing-contexts
+   *
+   * @param {string} eventName
+   *     The name of the event.
+   *
+   * @return {Set<string>} The set of browsing context.
+   */
+  #obtainEventEnabledBrowsingContextIds(eventName) {
+    const contextIds = new Set();
+    for (const [
+      contextId,
+      events,
+    ] of this.#browsingContextIdEventMap.entries()) {
+      if (events.has(eventName)) {
+        // Check that a browsing context still exists for a given id
+        const context = lazy.TabManager.getBrowsingContextById(contextId);
+        if (context) {
+          contextIds.add(contextId);
+        }
+      }
+    }
+
+    return contextIds;
+  }
+
+  #onMessageHandlerEvent = (name, event) => {
+    this.messageHandler.emitProtocolEvent(name, event);
+  };
+
+  /**
+   * Update global event state for top-level browsing contexts.
+   *
+   * @see https://w3c.github.io/webdriver-bidi/#update-the-event-map
+   *
+   * @param {Array<string>} requestedEventNames
+   *     The list of the event names to run the update for.
+   * @param {Array<string>|null} browsingContextIds
+   *     The list of the browsing context ids to update or null.
+   * @param {boolean} enabled
+   *     True, if events have to be enabled. Otherwise false.
+   *
+   * @return {Array<Subscription>} subscriptions
+   *     The list of information to subscribe/unsubscribe to.
+   *
+   * @throws {InvalidArgumentError}
+   *     If failed unsubscribe from event from <var>requestedEventNames</var> for
+   *     browsing context id from <var>browsingContextIds</var>, if present.
+   */
+  #updateEventMap(requestedEventNames, browsingContextIds, enabled) {
+    const globalEventSet = new Set(this.#globalEventSet);
+    const eventMap = structuredClone(this.#browsingContextIdEventMap);
+
+    const eventNames = new Set();
+
+    requestedEventNames.forEach(name => {
+      this.#obtainEvents(name).forEach(event => eventNames.add(event));
+    });
+    const enabledEvents = new Map();
+    const subscriptions = [];
+
+    if (browsingContextIds === null) {
+      // Subscribe or unsubscribe events for all browsing contexts.
+      if (enabled) {
+        // Subscribe to each event.
+
+        // Get the list of all top level browsing context ids.
+        const allTopBrowsingContextIds = lazy.TabManager.allBrowserUniqueIds;
+
+        for (const eventName of eventNames) {
+          if (!globalEventSet.has(eventName)) {
+            const alreadyEnabledContextIds = this.#obtainEventEnabledBrowsingContextIds(
+              eventName
+            );
+            globalEventSet.add(eventName);
+            for (const contextId of alreadyEnabledContextIds) {
+              eventMap.get(contextId).delete(eventName);
+
+              // Since we're going to subscribe to all top-level
+              // browsing context ids to not have duplicate subscriptions,
+              // we have to unsubscribe from already subscribed.
+              subscriptions.push({
+                event: eventName,
+                contextDescriptor: {
+                  type: lazy.ContextDescriptorType.TopBrowsingContext,
+                  id: this.#getBrowserIdForContextId(contextId),
+                },
+                callback: this.#onMessageHandlerEvent,
+                enable: false,
+              });
+            }
+
+            // Get a list of all top-level browsing context ids
+            // that are not contained in alreadyEnabledContextIds.
+            const newlyEnabledContextIds = allTopBrowsingContextIds.filter(
+              contextId => !alreadyEnabledContextIds.has(contextId)
+            );
+
+            enabledEvents.set(eventName, newlyEnabledContextIds);
+
+            subscriptions.push({
+              event: eventName,
+              contextDescriptor: {
+                type: lazy.ContextDescriptorType.All,
+              },
+              callback: this.#onMessageHandlerEvent,
+              enable: true,
+            });
+          }
+        }
+      } else {
+        // Unsubscribe each event which has a global subscription.
+        for (const eventName of eventNames) {
+          if (globalEventSet.has(eventName)) {
+            globalEventSet.delete(eventName);
+
+            subscriptions.push({
+              event: eventName,
+              contextDescriptor: {
+                type: lazy.ContextDescriptorType.All,
+              },
+              callback: this.#onMessageHandlerEvent,
+              enable: false,
+            });
+          } else {
+            throw new lazy.error.InvalidArgumentError(
+              `Failed to unsubscribe from event ${eventName}`
+            );
+          }
+        }
+      }
+    } else {
+      // Subscribe or unsubscribe events for given list of browsing context ids.
+      const targets = new Map();
+      for (const contextId of browsingContextIds) {
+        const topLevelContextId = this.#getTopBrowsingContextId(contextId);
+        if (!eventMap.has(topLevelContextId)) {
+          eventMap.set(topLevelContextId, new Set());
+        }
+        targets.set(topLevelContextId, eventMap.get(topLevelContextId));
+      }
+
+      for (const eventName of eventNames) {
+        // Do nothing if we want to subscribe,
+        // but the event has already a global subscription.
+        if (enabled && this.#globalEventSet.has(eventName)) {
+          continue;
+        }
+        for (const [contextId, target] of targets.entries()) {
+          // Subscribe if an event doesn't have a subscription for a specific context id.
+          if (enabled && !target.has(eventName)) {
+            target.add(eventName);
+            if (!enabledEvents.has(eventName)) {
+              enabledEvents.set(eventName, new Set());
+            }
+            enabledEvents.get(eventName).add(contextId);
+
+            subscriptions.push({
+              event: eventName,
+              contextDescriptor: {
+                type: lazy.ContextDescriptorType.TopBrowsingContext,
+                id: this.#getBrowserIdForContextId(contextId),
+              },
+              callback: this.#onMessageHandlerEvent,
+              enable: true,
+            });
+          } else if (!enabled) {
+            // Unsubscribe from each event for a specific context id if the event has a subscription.
+            if (target.has(eventName)) {
+              target.delete(eventName);
+
+              subscriptions.push({
+                event: eventName,
+                contextDescriptor: {
+                  type: lazy.ContextDescriptorType.TopBrowsingContext,
+                  id: this.#getBrowserIdForContextId(contextId),
+                },
+                callback: this.#onMessageHandlerEvent,
+                enable: false,
+              });
+            } else {
+              throw new lazy.error.InvalidArgumentError(
+                `Failed to unsubscribe from event ${eventName} for context ${contextId}`
+              );
+            }
+          }
+        }
+      }
+    }
+
+    this.#globalEventSet = globalEventSet;
+    this.#browsingContextIdEventMap = eventMap;
+
+    return subscriptions;
+  }
+}
+
+// To export the class as lower-case
+export const session = SessionModule;