puppeteer/src/launcher/BrowserRunner.ts

/**
 * Copyright 2020 Google Inc. All rights reserved.
 *
 * 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 * as debug from 'debug';

import * as removeFolder from 'rimraf';
import * as childProcess from 'child_process';
import { helper, assert, debugError } from '../helper';
import type { LaunchOptions } from './LaunchOptions';
import { Connection } from '../Connection';
import { WebSocketTransport } from '../WebSocketTransport';
import { PipeTransport } from '../PipeTransport';
import * as readline from 'readline';
import { TimeoutError } from '../Errors';

const removeFolderAsync = helper.promisify(removeFolder);
const debugLauncher = debug('puppeteer:launcher');

export class BrowserRunner {
  private _executablePath: string;
  private _processArguments: string[];
  private _tempDirectory?: string;

  proc = null;
  connection = null;

  private _closed = true;
  private _listeners = [];
  private _processClosing: Promise<void>;

  constructor(
    executablePath: string,
    processArguments: string[],
    tempDirectory?: string
  ) {
    this._executablePath = executablePath;
    this._processArguments = processArguments;
    this._tempDirectory = tempDirectory;
  }

  start(options: LaunchOptions = {}): void {
    const {
      handleSIGINT,
      handleSIGTERM,
      handleSIGHUP,
      dumpio,
      env,
      pipe,
    } = options;
    let stdio: Array<'ignore' | 'pipe'> = ['pipe', 'pipe', 'pipe'];
    if (pipe) {
      if (dumpio) stdio = ['ignore', 'pipe', 'pipe', 'pipe', 'pipe'];
      else stdio = ['ignore', 'ignore', 'ignore', 'pipe', 'pipe'];
    }
    assert(!this.proc, 'This process has previously been started.');
    debugLauncher(
      `Calling ${this._executablePath} ${this._processArguments.join(' ')}`
    );
    this.proc = childProcess.spawn(
      this._executablePath,
      this._processArguments,
      {
        // On non-windows platforms, `detached: true` makes child process a leader of a new
        // process group, making it possible to kill child process tree with `.kill(-pid)` command.
        // @see https://nodejs.org/api/child_process.html#child_process_options_detached
        detached: process.platform !== 'win32',
        env,
        stdio,
      }
    );
    if (dumpio) {
      this.proc.stderr.pipe(process.stderr);
      this.proc.stdout.pipe(process.stdout);
    }
    this._closed = false;
    this._processClosing = new Promise((fulfill) => {
      this.proc.once('exit', () => {
        this._closed = true;
        // Cleanup as processes exit.
        if (this._tempDirectory) {
          removeFolderAsync(this._tempDirectory)
            .then(() => fulfill())
            .catch((error) => console.error(error));
        } else {
          fulfill();
        }
      });
    });
    this._listeners = [
      helper.addEventListener(process, 'exit', this.kill.bind(this)),
    ];
    if (handleSIGINT)
      this._listeners.push(
        helper.addEventListener(process, 'SIGINT', () => {
          this.kill();
          process.exit(130);
        })
      );
    if (handleSIGTERM)
      this._listeners.push(
        helper.addEventListener(process, 'SIGTERM', this.close.bind(this))
      );
    if (handleSIGHUP)
      this._listeners.push(
        helper.addEventListener(process, 'SIGHUP', this.close.bind(this))
      );
  }

  close(): Promise<void> {
    if (this._closed) return Promise.resolve();
    helper.removeEventListeners(this._listeners);
    if (this._tempDirectory) {
      this.kill();
    } else if (this.connection) {
      // Attempt to close the browser gracefully
      this.connection.send('Browser.close').catch((error) => {
        debugError(error);
        this.kill();
      });
    }
    return this._processClosing;
  }

  kill(): void {
    helper.removeEventListeners(this._listeners);
    if (this.proc && this.proc.pid && !this.proc.killed && !this._closed) {
      try {
        if (process.platform === 'win32')
          childProcess.execSync(`taskkill /pid ${this.proc.pid} /T /F`);
        else process.kill(-this.proc.pid, 'SIGKILL');
      } catch (error) {
        // the process might have already stopped
      }
    }
    // Attempt to remove temporary profile directory to avoid littering.
    try {
      removeFolder.sync(this._tempDirectory);
    } catch (error) {}
  }

  async setupConnection(options: {
    usePipe?: boolean;
    timeout: number;
    slowMo: number;
    preferredRevision: string;
  }): Promise<Connection> {
    const { usePipe, timeout, slowMo, preferredRevision } = options;
    if (!usePipe) {
      const browserWSEndpoint = await waitForWSEndpoint(
        this.proc,
        timeout,
        preferredRevision
      );
      const transport = await WebSocketTransport.create(browserWSEndpoint);
      this.connection = new Connection(browserWSEndpoint, transport, slowMo);
    } else {
      // stdio was assigned during start(), and the 'pipe' option there adds the 4th and 5th items to stdio array
      const { 3: pipeWrite, 4: pipeRead } = this.proc.stdio;
      const transport = new PipeTransport(
        pipeWrite as NodeJS.WritableStream,
        pipeRead as NodeJS.ReadableStream
      );
      this.connection = new Connection('', transport, slowMo);
    }
    return this.connection;
  }
}

function waitForWSEndpoint(
  browserProcess: childProcess.ChildProcess,
  timeout: number,
  preferredRevision: string
): Promise<string> {
  return new Promise((resolve, reject) => {
    const rl = readline.createInterface({ input: browserProcess.stderr });
    let stderr = '';
    const listeners = [
      helper.addEventListener(rl, 'line', onLine),
      helper.addEventListener(rl, 'close', () => onClose()),
      helper.addEventListener(browserProcess, 'exit', () => onClose()),
      helper.addEventListener(browserProcess, 'error', (error) =>
        onClose(error)
      ),
    ];
    const timeoutId = timeout ? setTimeout(onTimeout, timeout) : 0;

    /**
     * @param {!Error=} error
     */
    function onClose(error?: Error): void {
      cleanup();
      reject(
        new Error(
          [
            'Failed to launch the browser process!' +
              (error ? ' ' + error.message : ''),
            stderr,
            '',
            'TROUBLESHOOTING: https://github.com/puppeteer/puppeteer/blob/master/docs/troubleshooting.md',
            '',
          ].join('\n')
        )
      );
    }

    function onTimeout(): void {
      cleanup();
      reject(
        new TimeoutError(
          `Timed out after ${timeout} ms while trying to connect to the browser! Only Chrome at revision r${preferredRevision} is guaranteed to work.`
        )
      );
    }

    function onLine(line: string): void {
      stderr += line + '\n';
      const match = line.match(/^DevTools listening on (ws:\/\/.*)$/);
      if (!match) return;
      cleanup();
      resolve(match[1]);
    }

    function cleanup(): void {
      if (timeoutId) clearTimeout(timeoutId);
      helper.removeEventListeners(listeners);
    }
  });
}