chore: drop Node.js v6 support (puppeteer#5045)

Node.js v6 was end-of-life'd in April, 2019, with AWS Lambda prohibiting updaets to the Node.js v6 runtime since June 30, 2019.

This makes it quite safe for us to remove the Node 6 support from the repository.

.appveyor.yml

@@ -1,8 +1,6 @@
 environment:
   matrix:
-    - nodejs_version: "6.12.3"
-      FLAKINESS_DASHBOARD_NAME: Appveyor Chromium (Win + node6)
-    - nodejs_version: "8.11.3"
+    - nodejs_version: "8.16.0"
       FLAKINESS_DASHBOARD_NAME: Appveyor Chromium (Win + node8)
   FLAKINESS_DASHBOARD_PASSWORD:
     secure: g66jP+j6C+hkXLutBV9fdxB5fRJgcQQzy93SgQzXUmcCl/RjkJwnzyHvX0xfCVnv
@@ -13,11 +11,9 @@ install:
   - ps: $env:FLAKINESS_DASHBOARD_BUILD_URL="https://ci.appveyor.com/project/aslushnikov/puppeteer/builds/$env:APPVEYOR_BUILD_ID/job/$env:APPVEYOR_JOB_ID"
   - ps: Install-Product node $env:nodejs_version
   - npm install
-  - if "%nodejs_version%" == "8.11.3" (
+  - if "%nodejs_version%" == "8.16.0" (
       npm run lint &&
       npm run coverage  &&
       npm run test-doclint &&
       npm run test-types
-    ) else (
-      npm run unit-node6
     )

.cirrus.yml

@@ -4,15 +4,6 @@ env:
   FLAKINESS_DASHBOARD_NAME: Cirrus ${CIRRUS_TASK_NAME}
   FLAKINESS_DASHBOARD_BUILD_URL: https://cirrus-ci.com/task/${CIRRUS_TASK_ID}
 
-task:
-  matrix:
-    - name: Chromium (node6 + linux)
-      container:
-        dockerfile: .ci/node6/Dockerfile.linux
-      xvfb_start_background_script: Xvfb :99 -ac -screen 0 1024x768x24
-  install_script: npm install --unsafe-perm
-  test_script: npm run unit-node6
-
 task:
   matrix:
     - name: Chromium (node8 + linux)

.travis.yml

@@ -24,24 +24,18 @@ script:
   - 'if [ "$NODE8" = "true" ]; then npm run test-types; fi'
   - 'if [ "$NODE8" = "true" ]; then npm run bundle; fi'
   - 'if [ "$NODE8" = "true" ]; then npm run unit-bundle; fi'
-  - 'if [ "$NODE6" = "true" ]; then npm run unit-node6; fi'
 jobs:
   include:
-    - node_js: "8.11.3"
+    - node_js: "8.16.0"
       env:
         - NODE8=true
         - FLAKINESS_DASHBOARD_NAME="Travis Chromium (node8 + linux)"
         - FLAKINESS_DASHBOARD_BUILD_URL="${TRAVIS_JOB_WEB_URL}"
-    - node_js: "8.11.3"
+    - node_js: "8.16.0"
       env:
         - FIREFOX=true
         - FLAKINESS_DASHBOARD_NAME="Travis Firefox (node8 + linux)"
         - FLAKINESS_DASHBOARD_BUILD_URL="${TRAVIS_JOB_WEB_URL}"
-    - node_js: "6.12.3"
-      env:
-        - NODE6=true
-        - FLAKINESS_DASHBOARD_NAME="Travis Chromium (node6 + linux)"
-        - FLAKINESS_DASHBOARD_BUILD_URL="${TRAVIS_JOB_WEB_URL}"
 before_deploy: "npm run apply-next-version"
 deploy:
   provider: npm

DeviceDescriptors.js

@@ -14,15 +14,4 @@
  * limitations under the License.
  */
 
-let asyncawait = true;
-try {
-  new Function('async function test(){await 1}');
-} catch (error) {
-  asyncawait = false;
-}
-
-// If node does not support async await, use the compiled version.
-if (asyncawait)
-  module.exports = require('./lib/DeviceDescriptors');
-else
-  module.exports = require('./node6/lib/DeviceDescriptors');
+module.exports = require('./lib/DeviceDescriptors');

Errors.js

@@ -14,15 +14,4 @@
  * limitations under the License.
  */
 
-let asyncawait = true;
-try {
-  new Function('async function test(){await 1}');
-} catch (error) {
-  asyncawait = false;
-}
-
-// If node does not support async await, use the compiled version.
-if (asyncawait)
-  module.exports = require('./lib/Errors');
-else
-  module.exports = require('./node6/lib/Errors');
+module.exports = require('./lib/Errors');

README.md

@@ -57,7 +57,10 @@ See [puppeteer vs puppeteer-core](https://github.com/GoogleChrome/puppeteer/blob
 
 ### Usage
 
-Note: Puppeteer requires at least Node v6.4.0, but the examples below use async/await which is only supported in Node v7.6.0 or greater.
+Puppeteer follows the latest [maintenance LTS](https://github.com/nodejs/Release#release-schedule) version of Node.
+
+Note: Prior to v1.18.1, Puppeteer required at least Node v6.4.0. All subsequent versions rely on
+Node 8.9.0+. All examples below use async/await which is only supported in Node v7.6.0 or greater.
 
 Puppeteer will be familiar to people using other browser testing frameworks. You create an instance
 of `Browser`, open pages, and then manipulate them with [Puppeteer's API](https://github.com/GoogleChrome/puppeteer/blob/v1.20.0/docs/api.md#).

experimental/puppeteer-firefox/DeviceDescriptors.js

@@ -14,15 +14,4 @@
  * limitations under the License.
  */
 
-let asyncawait = true;
-try {
-  new Function('async function test(){await 1}');
-} catch (error) {
-  asyncawait = false;
-}
-
-// If node does not support async await, use the compiled version.
-if (asyncawait)
-  module.exports = require('./lib/DeviceDescriptors');
-else
-  module.exports = require('./node6/lib/DeviceDescriptors');
+module.exports = require('./lib/DeviceDescriptors');

experimental/puppeteer-firefox/lib/Page.js

@@ -4,7 +4,6 @@ const {Dialog} = require('./Dialog');
 const {TimeoutError} = require('./Errors');
 const fs = require('fs');
 const mime = require('mime');
-const util = require('util');
 const EventEmitter = require('events');
 const {createHandle} = require('./JSHandle');
 const {Events} = require('./Events');
@@ -15,7 +14,7 @@ const {TimeoutSettings} = require('./TimeoutSettings');
 const {NavigationWatchdog} = require('./NavigationWatchdog');
 const {Accessibility} = require('./Accessibility');
 
-const writeFileAsync = util.promisify(fs.writeFile);
+const writeFileAsync = helper.promisify(fs.writeFile);
 
 class Page extends EventEmitter {
   /**

experimental/puppeteer-firefox/lib/helper.js

@@ -65,6 +65,10 @@ class Helper {
     }
   }
 
+  /**
+   * @param {function} nodeFunction
+   * @return {function}
+   */
   static promisify(nodeFunction) {
     function promisified(...args) {
       return new Promise((resolve, reject) => {

experimental/puppeteer-firefox/misc/install-preferences.js

@@ -1,14 +1,14 @@
 const os = require('os');
 const fs = require('fs');
 const path = require('path');
+const util = require('util');
 
 // Install browser preferences after downloading and unpacking
 // firefox instances.
 // Based on:   https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Enterprise_deployment_before_60#Configuration
 async function installFirefoxPreferences(executablePath) {
   const firefoxFolder = path.dirname(executablePath);
-  const {helper} = require('../lib/helper');
-  const mkdirAsync = helper.promisify(fs.mkdir.bind(fs));
+  const mkdirAsync = util.promisify(fs.mkdir.bind(fs));
 
   let prefPath = '';
   let configPath = '';

index.js

@@ -14,25 +14,16 @@
  * limitations under the License.
  */
 
-let asyncawait = true;
-try {
-  new Function('async function test(){await 1}');
-} catch (error) {
-  asyncawait = false;
-}
-
-if (asyncawait) {
-  const {helper} = require('./lib/helper');
-  const api = require('./lib/api');
-  for (const className in api) {
-    // Puppeteer-web excludes certain classes from bundle, e.g. BrowserFetcher.
-    if (typeof api[className] === 'function')
-      helper.installAsyncStackHooks(api[className]);
-  }
+const {helper} = require('./lib/helper');
+const api = require('./lib/api');
+for (const className in api) {
+  // Puppeteer-web excludes certain classes from bundle, e.g. BrowserFetcher.
+  if (typeof api[className] === 'function')
+    helper.installAsyncStackHooks(api[className]);
 }
 
 // If node does not support async await, use the compiled version.
-const Puppeteer = asyncawait ? require('./lib/Puppeteer') : require('./node6/lib/Puppeteer');
+const Puppeteer = require('./lib/Puppeteer');
 const packageJson = require('./package.json');
 const preferredRevision = packageJson.puppeteer.chromium_revision;
 const isPuppeteerCore = packageJson.name === 'puppeteer-core';

install.js

@@ -18,8 +18,6 @@
 if (require('./package.json').name === 'puppeteer-core')
   return;
 
-buildNode6IfNecessary();
-
 if (process.env.PUPPETEER_SKIP_CHROMIUM_DOWNLOAD) {
   logPolitely('**INFO** Skipping Chromium download. "PUPPETEER_SKIP_CHROMIUM_DOWNLOAD" environment variable was found.');
   return;
@@ -109,34 +107,7 @@ function toMegabytes(bytes) {
   return `${Math.round(mb * 10) / 10} Mb`;
 }
 
-function buildNode6IfNecessary() {
-  const fs = require('fs');
-  const path = require('path');
-
-  // if this package is installed from NPM, then it already has up-to-date node6
-  // folder.
-  if (!fs.existsSync(path.join('utils', 'node6-transform')))
-    return;
-  // if async/await is supported, then node6 is not needed.
-  if (supportsAsyncAwait())
-    return;
-  // Re-build node6/ folder.
-  logPolitely('Building Puppeteer for Node 6');
-  require(path.join(__dirname, 'utils', 'node6-transform'));
-}
-
-function supportsAsyncAwait() {
-  try {
-    new Function('async function test(){await 1}');
-  } catch (error) {
-    return false;
-  }
-  return true;
-}
-
 function generateProtocolTypesIfNecessary(updated) {
-  if (!supportsAsyncAwait())
-    return;
   const fs = require('fs');
   const path = require('path');
   if (!fs.existsSync(path.join(__dirname, 'utils', 'protocol-types-generator')))

lib/BrowserFetcher.js

@@ -17,8 +17,8 @@
 const os = require('os');
 const fs = require('fs');
 const path = require('path');
-const extract = require('extract-zip');
 const util = require('util');
+const extract = require('extract-zip');
 const URL = require('url');
 const {helper, assert} = require('./helper');
 const removeRecursive = require('rimraf');

lib/Page.js

@@ -31,6 +31,7 @@ const {Worker} = require('./Worker');
 const {createJSHandle} = require('./JSHandle');
 const {Accessibility} = require('./Accessibility');
 const {TimeoutSettings} = require('./TimeoutSettings');
+
 const writeFileAsync = helper.promisify(fs.writeFile);
 
 class Page extends EventEmitter {

lib/helper.js

@@ -156,6 +156,10 @@ class Helper {
     return typeof obj === 'number' || obj instanceof Number;
   }
 
+  /**
+   * @param {function} nodeFunction
+   * @return {function}
+   */
   static promisify(nodeFunction) {
     function promisified(...args) {
       return new Promise((resolve, reject) => {

package.json

@@ -5,7 +5,7 @@
   "main": "index.js",
   "repository": "github:GoogleChrome/puppeteer",
   "engines": {
-    "node": ">=6.4.0"
+    "node": ">=8.16.0"
   },
   "puppeteer": {
     "chromium_revision": "686378"
@@ -15,14 +15,11 @@
     "funit": "BROWSER=firefox node test/test.js",
     "debug-unit": "node --inspect-brk test/test.js",
     "test-doclint": "node utils/doclint/check_public_api/test/test.js && node utils/doclint/preprocessor/test.js",
-    "test": "npm run lint --silent && npm run coverage && npm run test-doclint && npm run test-node6-transformer && npm run test-types && node utils/testrunner/test/test.js",
+    "test": "npm run lint --silent && npm run coverage && npm run test-doclint && npm run test-types && node utils/testrunner/test/test.js",
     "install": "node install.js",
     "lint": "([ \"$CI\" = true ] && eslint --quiet -f codeframe . || eslint .) && npm run tsc && npm run doc",
     "doc": "node utils/doclint/cli.js",
     "coverage": "cross-env COVERAGE=true npm run unit",
-    "test-node6-transformer": "node utils/node6-transform/test/test.js",
-    "build": "node utils/node6-transform/index.js && node utils/doclint/generate_types",
-    "unit-node6": "node node6/test/test.js",
     "tsc": "tsc -p .",
     "prepublishOnly": "npm run build",
     "apply-next-version": "node utils/apply_next_version.js",
@@ -63,7 +60,6 @@
   },
   "browser": {
     "./lib/BrowserFetcher.js": false,
-    "./node6/lib/Puppeteer": false,
     "ws": "./utils/browser/WebSocket",
     "fs": false,
     "child_process": false,

test/evaluation.spec.js

@@ -16,13 +16,6 @@
 
 const utils = require('./utils');
 
-let asyncawait = true;
-try {
-  new Function('async function foo() {await 1}');
-} catch (e) {
-  asyncawait = false;
-}
-
 const bigint = typeof BigInt !== 'undefined';
 
 module.exports.addTests = function({testRunner, expect}) {
@@ -74,14 +67,12 @@ module.exports.addTests = function({testRunner, expect}) {
     it_fails_ffox('should return undefined for objects with symbols', async({page, server}) => {
       expect(await page.evaluate(() => [Symbol('foo4')])).toBe(undefined);
     });
-    (asyncawait ? it : xit)('should work with function shorthands', async({page, server}) => {
-      // trick node6 transpiler to not touch our object.
-      // TODO(lushnikov): remove eval once Node6 is dropped.
-      const a = eval(`({
+    it('should work with function shorthands', async({page, server}) => {
+      const a = {
         sum(a, b) { return a + b; },
 
         async mult(a, b) { return a * b; }
-      })`);
+      };
       expect(await page.evaluate(a.sum, 1, 2)).toBe(3);
       expect(await page.evaluate(a.mult, 2, 4)).toBe(8);
     });

test/headful.spec.js

@@ -17,11 +17,12 @@
 const path = require('path');
 const os = require('os');
 const fs = require('fs');
-const {helper} = require('../lib/helper');
-const rmAsync = helper.promisify(require('rimraf'));
+const util = require('util');
 const utils = require('./utils');
 const {waitEvent} = utils;
-const mkdtempAsync = helper.promisify(fs.mkdtemp);
+
+const rmAsync = util.promisify(require('rimraf'));
+const mkdtempAsync = util.promisify(fs.mkdtemp);
 
 const TMP_FOLDER = path.join(os.tmpdir(), 'pptr_tmp_folder-');
 

test/launcher.spec.js

@@ -233,9 +233,10 @@ module.exports.addTests = function({testRunner, expect, defaultBrowserOptions, p
         const browser = await puppeteer.launch(options);
         const pages = await browser.pages();
         expect(pages.length).toBe(1);
-        if (pages[0].url() !== server.EMPTY_PAGE)
-          await pages[0].waitForNavigation();
-        expect(pages[0].url()).toBe(server.EMPTY_PAGE);
+        const page = pages[0];
+        if (page.url() !== server.EMPTY_PAGE)
+          await page.waitForNavigation();
+        expect(page.url()).toBe(server.EMPTY_PAGE);
         await browser.close();
       });
       it('should set the default viewport', async() => {