gecko-dev/remote/webdriver-bidi/WebDriverBiDi.sys.mjs

241 lines
6.8 KiB
JavaScript

/* 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/. */
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
error: "chrome://remote/content/shared/webdriver/Errors.sys.mjs",
Log: "chrome://remote/content/shared/Log.sys.mjs",
WebDriverNewSessionHandler:
"chrome://remote/content/webdriver-bidi/NewSessionHandler.sys.mjs",
WebDriverSession: "chrome://remote/content/shared/webdriver/Session.sys.mjs",
});
ChromeUtils.defineLazyGetter(lazy, "logger", () =>
lazy.Log.get(lazy.Log.TYPES.WEBDRIVER_BIDI)
);
ChromeUtils.defineLazyGetter(lazy, "textEncoder", () => new TextEncoder());
/**
* Entry class for the WebDriver BiDi support.
*
* @see https://w3c.github.io/webdriver-bidi
*/
export class WebDriverBiDi {
/**
* Creates a new instance of the WebDriverBiDi class.
*
* @param {RemoteAgent} agent
* Reference to the Remote Agent instance.
*/
constructor(agent) {
this.agent = agent;
this._running = false;
this._session = null;
this._sessionlessConnections = new Set();
}
get address() {
return `ws://${this.agent.host}:${this.agent.port}`;
}
get session() {
return this._session;
}
/**
* Add a new connection that is not yet attached to a WebDriver session.
*
* @param {WebDriverBiDiConnection} connection
* The connection without an accociated WebDriver session.
*/
addSessionlessConnection(connection) {
this._sessionlessConnections.add(connection);
}
/**
* Create a new WebDriver session.
*
* @param {Object<string, *>=} capabilities
* JSON Object containing any of the recognised capabilities as listed
* on the `WebDriverSession` class.
*
* @param {WebDriverBiDiConnection=} sessionlessConnection
* Optional connection that is not yet accociated with a WebDriver
* session, and has to be associated with the new WebDriver session.
*
* @returns {Object<string, Capabilities>}
* Object containing the current session ID, and all its capabilities.
*
* @throws {SessionNotCreatedError}
* If, for whatever reason, a session could not be created.
*/
async createSession(capabilities, sessionlessConnection) {
if (this.session) {
throw new lazy.error.SessionNotCreatedError(
"Maximum number of active sessions"
);
}
const session = new lazy.WebDriverSession(
capabilities,
sessionlessConnection
);
// When the Remote Agent is listening, and a BiDi WebSocket connection
// has been requested, register a path handler for the session.
let webSocketUrl = null;
if (
this.agent.running &&
(session.capabilities.get("webSocketUrl") || sessionlessConnection)
) {
// Creating a WebDriver BiDi session too early can cause issues with
// clients in not being able to find any available browsing context.
// Also when closing the application while it's still starting up can
// cause shutdown hangs. As such WebDriver BiDi will return a new session
// once the initial application window has finished initializing.
lazy.logger.debug(`Waiting for initial application window`);
await this.agent.browserStartupFinished;
this.agent.server.registerPathHandler(session.path, session);
webSocketUrl = `${this.address}${session.path}`;
lazy.logger.debug(`Registered session handler: ${session.path}`);
if (sessionlessConnection) {
// Remove temporary session-less connection
this._sessionlessConnections.delete(sessionlessConnection);
}
}
// Also update the webSocketUrl capability to contain the session URL if
// a path handler has been registered. Otherwise set its value to null.
session.capabilities.set("webSocketUrl", webSocketUrl);
this._session = session;
return {
sessionId: this.session.id,
capabilities: this.session.capabilities,
};
}
/**
* Delete the current WebDriver session.
*/
deleteSession() {
if (!this.session) {
return;
}
// When the Remote Agent is listening, and a BiDi WebSocket is active,
// unregister the path handler for the session.
if (this.agent.running && this.session.capabilities.get("webSocketUrl")) {
this.agent.server.registerPathHandler(this.session.path, null);
lazy.logger.debug(`Unregistered session handler: ${this.session.path}`);
}
this.session.destroy();
this._session = null;
}
/**
* Retrieve the readiness state of the remote end, regarding the creation of
* new WebDriverBiDi sessions.
*
* See https://w3c.github.io/webdriver-bidi/#command-session-status
*
* @returns {object}
* The readiness state.
*/
getSessionReadinessStatus() {
if (this.session) {
// We currently only support one session, see Bug 1720707.
return {
ready: false,
message: "Session already started",
};
}
return {
ready: true,
message: "",
};
}
/**
* Starts the WebDriver BiDi support.
*/
async start() {
if (this._running) {
return;
}
this._running = true;
// Install a HTTP handler for direct WebDriver BiDi connection requests.
this.agent.server.registerPathHandler(
"/session",
new lazy.WebDriverNewSessionHandler(this)
);
Cu.printStderr(`WebDriver BiDi listening on ${this.address}\n`);
// Write WebSocket connection details to the WebDriverBiDiServer.json file
// located within the application's profile.
this._bidiServerPath = PathUtils.join(
PathUtils.profileDir,
"WebDriverBiDiServer.json"
);
const data = {
ws_host: this.agent.host,
ws_port: this.agent.port,
};
try {
await IOUtils.write(
this._bidiServerPath,
lazy.textEncoder.encode(JSON.stringify(data, undefined, " "))
);
} catch (e) {
lazy.logger.warn(
`Failed to create ${this._bidiServerPath} (${e.message})`
);
}
}
/**
* Stops the WebDriver BiDi support.
*/
async stop() {
if (!this._running) {
return;
}
try {
await IOUtils.remove(this._bidiServerPath);
} catch (e) {
lazy.logger.warn(
`Failed to remove ${this._bidiServerPath} (${e.message})`
);
}
try {
// Close open session
this.deleteSession();
this.agent.server.registerPathHandler("/session", null);
// Close all open session-less connections
this._sessionlessConnections.forEach(connection => connection.close());
this._sessionlessConnections.clear();
} catch (e) {
lazy.logger.error("Failed to stop protocol", e);
} finally {
this._running = false;
}
}
}