Use const a lot fo places (puppeteer#188)

install.js

@@ -14,9 +14,9 @@
  * limitations under the License.
  */
 
-let Downloader = require('./utils/ChromiumDownloader');
-let revision = require('./package').puppeteer.chromium_revision;
-let ProgressBar = require('progress');
+const Downloader = require('./utils/ChromiumDownloader');
+const revision = require('./package').puppeteer.chromium_revision;
+const ProgressBar = require('progress');
 
 // Do nothing if the revision is already downloaded.
 if (Downloader.revisionInfo(Downloader.currentPlatform(), revision))

lib/Browser.js

@@ -14,20 +14,20 @@
  * limitations under the License.
  */
 
-let {Duplex} = require('stream');
-let path = require('path');
-let helper = require('./helper');
-let removeRecursive = require('rimraf').sync;
-let Page = require('./Page');
-let childProcess = require('child_process');
-let Downloader = require('../utils/ChromiumDownloader');
-let Connection = require('./Connection');
-let readline = require('readline');
-
-let CHROME_PROFILE_PATH = path.resolve(__dirname, '..', '.dev_profile');
+const {Duplex} = require('stream');
+const path = require('path');
+const helper = require('./helper');
+const removeRecursive = require('rimraf').sync;
+const Page = require('./Page');
+const childProcess = require('child_process');
+const Downloader = require('../utils/ChromiumDownloader');
+const Connection = require('./Connection');
+const readline = require('readline');
+
+const CHROME_PROFILE_PATH = path.resolve(__dirname, '..', '.dev_profile');
 let browserId = 0;
 
-let DEFAULT_ARGS = [
+const DEFAULT_ARGS = [
   '--disable-background-networking',
   '--disable-background-timer-throttling',
   '--disable-client-side-phishing-detection',

lib/Connection.js

@@ -13,11 +13,11 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-let debug = require('debug')('puppeteer:protocol');
+const debug = require('debug')('puppeteer:protocol');
 
-let EventEmitter = require('events');
-let WebSocket = require('ws');
-let http = require('http');
+const EventEmitter = require('events');
+const WebSocket = require('ws');
+const http = require('http');
 const COMMAND_TIMEOUT = 10000;
 
 class Connection extends EventEmitter {

lib/FrameManager.js

@@ -14,10 +14,10 @@
  * limitations under the License.
  */
 
-let fs = require('fs');
-let path = require('path');
-let EventEmitter = require('events');
-let helper = require('./helper');
+const fs = require('fs');
+const path = require('path');
+const EventEmitter = require('events');
+const helper = require('./helper');
 
 class FrameManager extends EventEmitter {
   /**

lib/Page.js

@@ -14,17 +14,17 @@
  * limitations under the License.
  */
 
-let fs = require('fs');
-let EventEmitter = require('events');
-let mime = require('mime');
-let NetworkManager = require('./NetworkManager');
-let NavigatorWatcher = require('./NavigatorWatcher');
-let Dialog = require('./Dialog');
-let EmulationManager = require('./EmulationManager');
-let FrameManager = require('./FrameManager');
-let {Keyboard, Mouse} = require('./Input');
-let Tracing = require('./Tracing');
-let helper = require('./helper');
+const fs = require('fs');
+const EventEmitter = require('events');
+const mime = require('mime');
+const NetworkManager = require('./NetworkManager');
+const NavigatorWatcher = require('./NavigatorWatcher');
+const Dialog = require('./Dialog');
+const EmulationManager = require('./EmulationManager');
+const FrameManager = require('./FrameManager');
+const {Keyboard, Mouse} = require('./Input');
+const Tracing = require('./Tracing');
+const helper = require('./helper');
 
 class Page extends EventEmitter {
   /**

phantom_shim/FileSystem.js

@@ -14,11 +14,11 @@
  * limitations under the License.
  */
 
-let path = require('path');
-let fs = require('fs');
-let deasync = require('deasync');
-let removeRecursive = require('rimraf').sync;
-let copyRecursive = deasync(require('ncp').ncp);
+const path = require('path');
+const fs = require('fs');
+const deasync = require('deasync');
+const removeRecursive = require('rimraf').sync;
+const copyRecursive = deasync(require('ncp').ncp);
 
 class FileSystem {
   constructor() {

phantom_shim/Phantom.js

@@ -14,10 +14,10 @@
  * limitations under the License.
  */
 
-let fs = require('fs');
-let path = require('path');
-let vm = require('vm');
-let url = require('url');
+const fs = require('fs');
+const path = require('path');
+const vm = require('vm');
+const url = require('url');
 
 const VERSION = [0, 0, 1];
 

phantom_shim/System.js

@@ -14,9 +14,9 @@
  * limitations under the License.
  */
 
-let readline = require('readline');
-let await = require('./utilities').await;
-let os = require('os');
+const readline = require('readline');
+const await = require('./utilities').await;
+const os = require('os');
 
 class System {
   /**

phantom_shim/WebPage.js

@@ -14,13 +14,13 @@
  * limitations under the License.
  */
 
-let await = require('./utilities').await;
-let EventEmitter = require('events');
-let fs = require('fs');
-let path = require('path');
-let PageEvents = require('../lib/Page').Events;
+const await = require('./utilities').await;
+const EventEmitter = require('events');
+const fs = require('fs');
+const path = require('path');
+const PageEvents = require('../lib/Page').Events;
 
-let noop = function() { };
+const noop = function() { };
 
 class WebPage {
   /**

phantom_shim/WebServer.js

@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-let http = require('http');
-let await = require('./utilities').await;
+const http = require('http');
+const await = require('./utilities').await;
 
 class WebServer {
   constructor() {

phantom_shim/runner.js

@@ -15,17 +15,17 @@
  * limitations under the License.
  */
 
-let vm = require('vm');
-let path = require('path');
-let fs = require('fs');
-let Phantom = require('./Phantom');
-let FileSystem = require('./FileSystem');
-let System = require('./System');
-let WebPage = require('./WebPage');
-let WebServer = require('./WebServer');
-let child_process = require('child_process');
-let Browser = require('..').Browser;
-let argv = require('minimist')(process.argv.slice(2), {
+const vm = require('vm');
+const path = require('path');
+const fs = require('fs');
+const Phantom = require('./Phantom');
+const FileSystem = require('./FileSystem');
+const System = require('./System');
+const WebPage = require('./WebPage');
+const WebServer = require('./WebServer');
+const child_process = require('child_process');
+const Browser = require('..').Browser;
+const argv = require('minimist')(process.argv.slice(2), {
   alias: { v: 'version' },
   boolean: ['headless'],
   default: {'headless': true },

phantom_shim/utilities.js

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-let loopWhile = require('deasync').loopWhile;
+const loopWhile = require('deasync').loopWhile;
 
 module.exports = {
   await: function(promise) {

test/golden-utils.js

@@ -13,12 +13,12 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-let path = require('path');
-let fs = require('fs');
-let Diff = require('text-diff');
-let mime = require('mime');
-let PNG = require('pngjs').PNG;
-let pixelmatch = require('pixelmatch');
+const path = require('path');
+const fs = require('fs');
+const Diff = require('text-diff');
+const mime = require('mime');
+const PNG = require('pngjs').PNG;
+const pixelmatch = require('pixelmatch');
 
 module.exports = {
   addMatchers: function(jasmine, goldenPath, outputPath) {

test/server/SimpleServer.js

@@ -14,13 +14,13 @@
  * limitations under the License.
  */
 
-let http = require('http');
-let https = require('https');
-let url = require('url');
-let fs = require('fs');
-let path = require('path');
-let mime = require('mime');
-let WebSocketServer = require('ws').Server;
+const http = require('http');
+const https = require('https');
+const url = require('url');
+const fs = require('fs');
+const path = require('path');
+const mime = require('mime');
+const WebSocketServer = require('ws').Server;
 
 const fulfillSymbol = Symbol('fullfill callback');
 const rejectSymbol = Symbol('reject callback');

test/test.js

@@ -14,24 +14,24 @@
  * limitations under the License.
  */
 
-let fs = require('fs');
-let rm = require('rimraf').sync;
-let path = require('path');
-let helper = require('../lib/helper');
+const fs = require('fs');
+const rm = require('rimraf').sync;
+const path = require('path');
+const helper = require('../lib/helper');
 if (process.env.COVERAGE)
   helper.recordPublicAPICoverage();
-let Browser = require('../lib/Browser');
-let SimpleServer = require('./server/SimpleServer');
-let GoldenUtils = require('./golden-utils');
-
-let GOLDEN_DIR = path.join(__dirname, 'golden');
-let OUTPUT_DIR = path.join(__dirname, 'output');
-
-let PORT = 8907;
-let PREFIX = 'http://localhost:' + PORT;
-let EMPTY_PAGE = PREFIX + '/empty.html';
-let HTTPS_PORT = 8908;
-let HTTPS_PREFIX = 'https://localhost:' + HTTPS_PORT;
+const Browser = require('../lib/Browser');
+const SimpleServer = require('./server/SimpleServer');
+const GoldenUtils = require('./golden-utils');
+
+const GOLDEN_DIR = path.join(__dirname, 'golden');
+const OUTPUT_DIR = path.join(__dirname, 'output');
+
+const PORT = 8907;
+const PREFIX = 'http://localhost:' + PORT;
+const EMPTY_PAGE = PREFIX + '/empty.html';
+const HTTPS_PORT = 8908;
+const HTTPS_PREFIX = 'https://localhost:' + HTTPS_PORT;
 
 const iPhone = require('../DeviceDescriptors')['iPhone 6'];
 const iPhoneLandscape = require('../DeviceDescriptors')['iPhone 6 landscape'];

utils/ChromiumDownloader.js

@@ -14,18 +14,18 @@
  * limitations under the License.
  */
 
-let os = require('os');
-let https = require('https');
-let fs = require('fs');
-let path = require('path');
-let extract = require('extract-zip');
-let util = require('util');
-let URL = require('url');
-let removeRecursive = require('rimraf');
+const os = require('os');
+const https = require('https');
+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');
 
-let DOWNLOADS_FOLDER = path.join(__dirname, '..', '.local-chromium');
+const DOWNLOADS_FOLDER = path.join(__dirname, '..', '.local-chromium');
 
-let downloadURLs = {
+const downloadURLs = {
   linux: 'https://storage.googleapis.com/chromium-browser-snapshots/Linux_x64/%d/chrome-linux.zip',
   mac: 'https://storage.googleapis.com/chromium-browser-snapshots/Mac/%d/chrome-mac.zip',
   win32: 'https://storage.googleapis.com/chromium-browser-snapshots/Win/%d/chrome-win32.zip',

utils/check_availability.js

@@ -15,11 +15,11 @@
  * limitations under the License.
  */
 
-let Downloader = require('./ChromiumDownloader');
-let https = require('https');
-let OMAHA_PROXY = 'https://omahaproxy.appspot.com/all.json';
+const Downloader = require('./ChromiumDownloader');
+const https = require('https');
+const OMAHA_PROXY = 'https://omahaproxy.appspot.com/all.json';
 
-let colors = {
+const colors = {
   reset: '\x1b[0m',
   red: '\x1b[31m',
   green: '\x1b[32m',