refactor: move ChromiumDownloader under lib/ (#1554)

This patch:
- renames ChromiumDownloader into just Downloader (this is in
  preparation for different products download)
- moves Downloader from utils/ to lib/. This unifies all of the
  production-critical code in the lib/.

Drive-by: make Downloader a regular class.

utils/ChromiumDownloader.js

@@ -1,245 +0,0 @@
-/**
- * Copyright 2017 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.
- */
-
-const os = require('os');
-const fs = require('fs');
-const path = require('path');
-const extract = require('extract-zip');
-const util = require('util');
-const URL = require('url');
-const removeRecursive = require('rimraf');
-// @ts-ignore
-const ProxyAgent = require('https-proxy-agent');
-// @ts-ignore
-const getProxyForUrl = require('proxy-from-env').getProxyForUrl;
-
-const DOWNLOADS_FOLDER = path.join(__dirname, '..', '.local-chromium');
-const DEFAULT_DOWNLOAD_HOST = 'https://storage.googleapis.com';
-
-const downloadURLs = {
-  linux: '%s/chromium-browser-snapshots/Linux_x64/%d/chrome-linux.zip',
-  mac: '%s/chromium-browser-snapshots/Mac/%d/chrome-mac.zip',
-  win32: '%s/chromium-browser-snapshots/Win/%d/chrome-win32.zip',
-  win64: '%s/chromium-browser-snapshots/Win_x64/%d/chrome-win32.zip',
-};
-
-module.exports = {
-  /**
-   * @return {!Array<string>}
-   */
-  supportedPlatforms: function() {
-    return Object.keys(downloadURLs);
-  },
-
-  /**
-   * @return {string}
-   */
-  currentPlatform: function() {
-    const platform = os.platform();
-    if (platform === 'darwin')
-      return 'mac';
-    if (platform === 'linux')
-      return 'linux';
-    if (platform === 'win32')
-      return os.arch() === 'x64' ? 'win64' : 'win32';
-    return '';
-  },
-
-  /**
-   * @param {string} platform
-   * @param {string} revision
-   * @return {!Promise<boolean>}
-   */
-  canDownloadRevision: function(platform, revision) {
-    console.assert(downloadURLs[platform], 'Unknown platform: ' + platform);
-
-    const url = util.format(downloadURLs[platform], DEFAULT_DOWNLOAD_HOST, revision);
-
-    let resolve;
-    const promise = new Promise(x => resolve = x);
-    const request = httpRequest(url, 'HEAD', response => {
-      resolve(response.statusCode === 200);
-    });
-    request.on('error', error => {
-      console.error(error);
-      resolve(false);
-    });
-    return promise;
-  },
-
-  /**
-   * @param {string} platform
-   * @param {string} revision
-   * @param {string} [downloadHost=DEFAULT_DOWNLOAD_HOST]
-   * @param {?function(number, number)} progressCallback
-   * @return {!Promise}
-   */
-  downloadRevision: function(platform, revision, downloadHost = DEFAULT_DOWNLOAD_HOST, progressCallback) {
-    let url = downloadURLs[platform];
-    console.assert(url, `Unsupported platform: ${platform}`);
-    url = util.format(url, downloadHost, revision);
-    const zipPath = path.join(DOWNLOADS_FOLDER, `download-${platform}-${revision}.zip`);
-    const folderPath = getFolderPath(platform, revision);
-    if (fs.existsSync(folderPath))
-      return;
-    if (!fs.existsSync(DOWNLOADS_FOLDER))
-      fs.mkdirSync(DOWNLOADS_FOLDER);
-    return downloadFile(url, zipPath, progressCallback)
-        .then(() => extractZip(zipPath, folderPath))
-        .catch(err => err)
-        .then(err => {
-          if (fs.existsSync(zipPath))
-            fs.unlinkSync(zipPath);
-          if (err)
-            throw err;
-        });
-  },
-
-  /**
-   * @return {!Array<!{platform:string, revision: string}>}
-   */
-  downloadedRevisions: function() {
-    if (!fs.existsSync(DOWNLOADS_FOLDER))
-      return [];
-    const fileNames = fs.readdirSync(DOWNLOADS_FOLDER);
-    return fileNames.map(fileName => parseFolderPath(fileName)).filter(revision => !!revision);
-  },
-
-  /**
-   * @param {string} platform
-   * @param {string} revision
-   * @return {!Promise}
-   */
-  removeRevision: function(platform, revision) {
-    console.assert(downloadURLs[platform], `Unsupported platform: ${platform}`);
-    const folderPath = getFolderPath(platform, revision);
-    console.assert(fs.existsSync(folderPath));
-    return new Promise(fulfill => removeRecursive(folderPath, fulfill));
-  },
-
-  /**
-   * @param {string} platform
-   * @param {string} revision
-   * @return {!{folderPath: string, executablePath: string, downloaded: boolean}}
-   */
-  revisionInfo: function(platform, revision) {
-    console.assert(downloadURLs[platform], `Unsupported platform: ${platform}`);
-    const folderPath = getFolderPath(platform, revision);
-    let executablePath = '';
-    if (platform === 'mac')
-      executablePath = path.join(folderPath, 'chrome-mac', 'Chromium.app', 'Contents', 'MacOS', 'Chromium');
-    else if (platform === 'linux')
-      executablePath = path.join(folderPath, 'chrome-linux', 'chrome');
-    else if (platform === 'win32' || platform === 'win64')
-      executablePath = path.join(folderPath, 'chrome-win32', 'chrome.exe');
-    else
-      throw 'Unsupported platform: ' + platform;
-    return {
-      executablePath,
-      folderPath,
-      downloaded: fs.existsSync(folderPath)
-    };
-  },
-};
-
-/**
- * @param {string} platform
- * @param {string} revision
- * @return {string}
- */
-function getFolderPath(platform, revision) {
-  return path.join(DOWNLOADS_FOLDER, platform + '-' + revision);
-}
-
-/**
- * @param {string} folderPath
- * @return {?{platform: string, revision: string}}
- */
-function parseFolderPath(folderPath) {
-  const name = path.basename(folderPath);
-  const splits = name.split('-');
-  if (splits.length !== 2)
-    return null;
-  const [platform, revision] = splits;
-  if (!downloadURLs[platform])
-    return null;
-  return {platform, revision};
-}
-
-/**
- * @param {string} url
- * @param {string} destinationPath
- * @param {?function(number, number)} progressCallback
- * @return {!Promise}
- */
-function downloadFile(url, destinationPath, progressCallback) {
-  let fulfill, reject;
-
-  const promise = new Promise((x, y) => { fulfill = x; reject = y; });
-
-  const request = httpRequest(url, 'GET', response => {
-    if (response.statusCode !== 200) {
-      const error = new Error(`Download failed: server returned code ${response.statusCode}. URL: ${url}`);
-      // consume response data to free up memory
-      response.resume();
-      reject(error);
-      return;
-    }
-    const file = fs.createWriteStream(destinationPath);
-    file.on('finish', () => fulfill());
-    file.on('error', error => reject(error));
-    response.pipe(file);
-    const totalBytes = parseInt(/** @type {string} */ (response.headers['content-length']), 10);
-    if (progressCallback)
-      response.on('data', onData.bind(null, totalBytes));
-  });
-  request.on('error', error => reject(error));
-  return promise;
-
-  function onData(totalBytes, chunk) {
-    progressCallback(totalBytes, chunk.length);
-  }
-}
-
-/**
- * @param {string} zipPath
- * @param {string} folderPath
- * @return {!Promise<?Error>}
- */
-function extractZip(zipPath, folderPath) {
-  return new Promise(fulfill => extract(zipPath, {dir: folderPath}, fulfill));
-}
-
-function httpRequest(url, method, response) {
-  /** @type {Object} */
-  const options = URL.parse(url);
-  options.method = method;
-
-  const proxyURL = getProxyForUrl(url);
-  if (proxyURL) {
-    /** @type {Object} */
-    const parsedProxyURL = URL.parse(proxyURL);
-    parsedProxyURL.secureProxy = parsedProxyURL.protocol === 'https:';
-
-    options.agent = new ProxyAgent(parsedProxyURL);
-    options.rejectUnauthorized = false;
-  }
-
-  const driver = options.protocol === 'https:' ? 'https' : 'http';
-  const request = require(driver).request(options, response);
-  request.end();
-  return request;
-}

utils/check_availability.js

@@ -15,10 +15,12 @@
  * limitations under the License.
  */
 
-const Downloader = require('./ChromiumDownloader');
+const Downloader = require('../lib/Downloader');
 const https = require('https');
 const OMAHA_PROXY = 'https://omahaproxy.appspot.com/all.json';
 
+const downloader = Downloader.createDefault();
+
 const colors = {
   reset: '\x1b[0m',
   red: '\x1b[31m',
@@ -71,7 +73,7 @@ async function checkOmahaProxyAvailability() {
     return;
   }
   const table = new Table([27, 7, 7, 7, 7]);
-  table.drawRow([''].concat(Downloader.supportedPlatforms()));
+  table.drawRow([''].concat(downloader.supportedPlatforms()));
   for (const platform of platforms) {
     // Trust only to the main platforms.
     if (platform.os !== 'mac' && platform.os !== 'win' && platform.os !== 'win64' && platform.os !== 'linux')
@@ -93,7 +95,7 @@ async function checkOmahaProxyAvailability() {
  */
 async function checkRangeAvailability(fromRevision, toRevision) {
   const table = new Table([10, 7, 7, 7, 7]);
-  table.drawRow([''].concat(Downloader.supportedPlatforms()));
+  table.drawRow([''].concat(downloader.supportedPlatforms()));
   const inc = fromRevision < toRevision ? 1 : -1;
   for (let revision = fromRevision; revision !== toRevision; revision += inc)
     await checkAndDrawRevisionAvailability(table, '', revision);
@@ -106,8 +108,8 @@ async function checkRangeAvailability(fromRevision, toRevision) {
  */
 async function checkAndDrawRevisionAvailability(table, name, revision) {
   const promises = [];
-  for (const platform of Downloader.supportedPlatforms())
-    promises.push(Downloader.canDownloadRevision(platform, revision));
+  for (const platform of downloader.supportedPlatforms())
+    promises.push(downloader.canDownloadRevision(platform, revision));
   const availability = await Promise.all(promises);
   const allAvailable = availability.every(e => !!e);
   const values = [name + ' ' + (allAvailable ? colors.green + revision + colors.reset : revision)];

utils/doclint/check_public_api/index.js

@@ -21,6 +21,7 @@ const Message = require('../Message');
 
 const EXCLUDE_CLASSES = new Set([
   'Connection',
+  'Downloader',
   'EmulationManager',
   'FrameManager',
   'Helper',