misc: convert lighthouse-core/scripts to ES modules

lighthouse-core/lib/page-functions.js

@@ -530,17 +530,17 @@ module.exports = {
   getElementsInDocument,
   getElementsInDocumentString: getElementsInDocument.toString(),
   getOuterHTMLSnippetString: getOuterHTMLSnippet.toString(),
-  getOuterHTMLSnippet: getOuterHTMLSnippet,
-  computeBenchmarkIndex: computeBenchmarkIndex,
+  getOuterHTMLSnippet,
+  computeBenchmarkIndex,
   computeBenchmarkIndexString: computeBenchmarkIndex.toString(),
   getMaxTextureSize,
   getNodeDetailsString,
   getNodeDetails,
   getNodePathString: getNodePath.toString(),
   getNodeSelectorString: getNodeSelector.toString(),
   getNodePath,
-  getNodeSelector: getNodeSelector,
-  getNodeLabel: getNodeLabel,
+  getNodeSelector,
+  getNodeLabel,
   getNodeLabelString: getNodeLabel.toString(),
   isPositionFixedString: isPositionFixed.toString(),
   wrapRequestIdleCallback,

lighthouse-core/scripts/.eslintrc.cjs

@@ -0,0 +1,27 @@
+/**
+ * @license Copyright 2021 The Lighthouse Authors. 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.
+ */
+'use strict';
+
+module.exports = {
+  env: {
+    browser: true,
+  },
+  rules: {
+    // TODO(esmodules): move to root eslint when all code is ESM
+    // or when this is resolved: https://github.com/import-js/eslint-plugin-import/issues/2214
+    'import/order': [2, {
+      'groups': [
+        'builtin',
+        'external',
+        ['sibling', 'parent'],
+        'index',
+        'object',
+        'type',
+      ],
+      'newlines-between': 'always',
+    }],
+  },
+};

lighthouse-core/scripts/benchmark-plus-extras.js

@@ -5,14 +5,14 @@
  */
 'use strict';
 
-/* global document */
-
 /**
  * @fileoverview This script computes the BenchmarkIndex and a few other related browser benchmarks.
+ * node lighthouse-core/scripts/benchmark-plus-extras.js
  */
 
-const puppeteer = require('puppeteer');
-const {computeBenchmarkIndex} = require('../lib/page-functions.js');
+import puppeteer from 'puppeteer';
+
+import pageFunctions from '../lib/page-functions.js';
 
 /** @param {import('puppeteer').Page} page */
 async function runOctane(page) {
@@ -80,7 +80,7 @@ async function main() {
 
   process.stdout.write(`Running BenchmarkIndex...\n`);
   for (let i = 0; i < 10; i++) {
-    const BenchmarkIndex = await page.evaluate(computeBenchmarkIndex);
+    const BenchmarkIndex = await page.evaluate(pageFunctions.computeBenchmarkIndex);
     process.stdout.write(`  ${i + 1}: BenchmarkIndex=${BenchmarkIndex}\n`);
   }
 

lighthouse-core/scripts/benchmark.js

@@ -9,13 +9,15 @@
 
 /* eslint-disable no-console */
 
-const computeBenchmarkIndex = require('../lib/page-functions.js').computeBenchmarkIndex;
+// node lighthouse-core/scripts/benchmark.js
+
+import pageFunctions from '../lib/page-functions.js';
 
 console.log('Computing BenchmarkIndex 10 times...');
 
 let total = 0;
 for (let i = 0; i < 10; i++) {
-  const result = computeBenchmarkIndex();
+  const result = pageFunctions.computeBenchmarkIndex();
   console.log(`Result ${i + 1}: ${result.toFixed(0)}`);
   total += result;
 }

lighthouse-core/scripts/build-test-flow-report.js

@@ -5,19 +5,22 @@
  */
 'use strict';
 
-const fs = require('fs');
-const open = require('open');
-const {execFileSync} = require('child_process');
+// node lighthouse-core/scripts/build-test-flow-report.js
+
+import fs from 'fs';
+import {execFileSync} from 'child_process';
+
+import open from 'open';
+
+import reportGenerator from '../../report/generator/report-generator.js';
+import {LH_ROOT, readJson} from '../../root.js';
 
 execFileSync(`yarn`, ['build-report', '--standalone']);
-const reportGenerator = require('../../report/generator/report-generator.js');
 
-const flow = JSON.parse(fs.readFileSync(
-      `${__dirname}/../test/fixtures/fraggle-rock/reports/sample-lhrs.json`,
-      'utf-8')
-);
+const flow = readJson(
+      `${LH_ROOT}/lighthouse-core/test/fixtures/fraggle-rock/reports/sample-lhrs.json`);
 
 const htmlReport = reportGenerator.generateFlowReportHtml(flow);
 
-fs.writeFileSync(`${__dirname}/../../flow.report.html`, htmlReport);
-open(`${__dirname}/../../flow.report.html`);
+fs.writeFileSync(`${LH_ROOT}/flow.report.html`, htmlReport);
+open(`${LH_ROOT}/flow.report.html`);

lighthouse-core/scripts/cleanup-LHR-for-diff.js

@@ -9,7 +9,7 @@
 
 /** @fileoverview Read in a LHR JSON file, remove whatever shouldn't be compared, write it back. */
 
-const {readFileSync, writeFileSync} = require('fs');
+import {readFileSync, writeFileSync} from 'fs';
 
 const filename = process.argv[2];
 const extraFlag = process.argv[3];

lighthouse-core/scripts/cleanup-vuln-snapshot.js

@@ -9,9 +9,14 @@
 
 /** @fileoverview Read in the snyk snapshot, remove whatever we don't need, write it back */
 
-const {readFileSync, writeFileSync} = require('fs');
-const prettyJSONStringify = require('pretty-json-stringify');
-const libDetectorSource = readFileSync(require.resolve('js-library-detector/library/libraries.js'),
+import {readFileSync, writeFileSync} from 'fs';
+
+import prettyJSONStringify from 'pretty-json-stringify';
+
+import {resolveModulePath} from './esm-utils.js';
+
+const libDetectorSource = readFileSync(
+  resolveModulePath('js-library-detector/library/libraries.js'),
   'utf8'
 );
 

lighthouse-core/scripts/compare-runs.js

@@ -15,19 +15,24 @@
 // The script will report both timings and perf metric results. View just one of them by using --filter:
 //     node lighthouse-core/scripts/compare-runs.js --summarize --name pr --filter=metric
 
-const fs = require('fs');
-const mkdir = fs.promises.mkdir;
-const glob = require('glob');
-const util = require('util');
-const execFile = util.promisify(require('child_process').execFile);
-const yargs = require('yargs');
-const {LH_ROOT} = require('../../root.js');
+import fs from 'fs';
+import util from 'util';
+import childProcess from 'child_process';
+
+import glob from 'glob';
+import yargs from 'yargs';
+import * as yargsHelpers from 'yargs/helpers';
 
-const {ProgressLogger} = require('./lantern/collect/common.js');
+import {LH_ROOT} from '../../root.js';
+import {ProgressLogger} from './lantern/collect/common.js';
+
+const mkdir = fs.promises.mkdir;
+const execFile = util.promisify(childProcess.execFile);
 
 const ROOT_OUTPUT_DIR = `${LH_ROOT}/timings-data`;
 
-const rawArgv = yargs
+const y = yargs(yargsHelpers.hideBin(process.argv));
+const rawArgv = y
   .help('help')
   .describe({
     // common flags
@@ -64,7 +69,7 @@ const rawArgv = yargs
   .default('sort-by-absolute-value', false)
   .default('lh-flags', '')
   .strict() // fail on unknown commands
-  .wrap(yargs.terminalWidth())
+  .wrap(y.terminalWidth())
   .argv;
 
 // Augmenting yargs type with auto-camelCasing breaks in tsc@4.1.2 and @types/yargs@15.0.11,

lighthouse-core/scripts/esm-utils.js

@@ -0,0 +1,18 @@
+/**
+ * @license Copyright 2021 The Lighthouse Authors. 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.
+ */
+'use strict';
+
+import module from 'module';
+
+const require = module.createRequire(import.meta.url);
+
+/**
+ * Commonjs equivalent of `require.resolve`.
+ * @param {string} packageName
+ */
+export function resolveModulePath(packageName) {
+  return require.resolve(packageName);
+}

lighthouse-core/scripts/gcp-collection/analyze-lhr-data.js

@@ -15,8 +15,8 @@
  */
 
 /* eslint-disable no-console */
-const {readdirSync, readFileSync} = require('fs');
-const {join} = require('path');
+import {readdirSync, readFileSync} from 'fs';
+import {join} from 'path';
 
 const directory = process.argv[2];
 const audit = process.argv[3];

lighthouse-core/scripts/gcp-collection/fleet-create-directories.js

@@ -12,14 +12,15 @@
  * USAGE: node lighthouse-core/scripts/gcp-collection/fleet-create-directories.js [<url list file>]
  */
 
-const fs = require('fs');
-const path = require('path');
-const {LH_ROOT} = require('../../../root.js');
+import fs from 'fs';
+import path from 'path';
+
+import {LH_ROOT} from '../../../root.js';
 
 const TMP_DIR = path.join(LH_ROOT, '.tmp/gcp-instances');
 const URLS_LIST = process.argv[2]
   ? path.resolve(process.cwd(), process.argv[2])
-  : path.join(__dirname, 'urls.txt');
+  : path.join(LH_ROOT, 'lighthouse-core/scripts/gcp-collection/urls.txt');
 
 fs.rmdirSync(TMP_DIR, {recursive: true});
 fs.mkdirSync(TMP_DIR);
@@ -44,9 +45,10 @@ instanceUrls.forEach((urls, i) => {
 
   const dir = path.join(TMP_DIR, `instance${MACHINE_BASE_INDEX + i}`);
   fs.mkdirSync(dir);
-  const files = fs.readdirSync(__dirname).filter(f => f.endsWith('.sh'));
+  const scriptDir = `${LH_ROOT}/lighthouse-core/scripts/gcp-collection`;
+  const files = fs.readdirSync(scriptDir).filter(f => f.endsWith('.sh'));
   files.forEach(f =>
-    fs.copyFileSync(path.join(__dirname, f), path.join(dir, f))
+    fs.copyFileSync(path.join(scriptDir, f), path.join(dir, f))
   );
   fs.writeFileSync(path.join(dir, 'urls.txt'), urls.join('\n'));
 });

lighthouse-core/scripts/generate-timing-trace.js

@@ -5,18 +5,21 @@
  */
 'use strict';
 
-const fs = require('fs');
-const path = require('path');
-const {createTraceString} = require('../lib/timing-trace-saver.js');
-
 /**
  * @fileoverview This script takes the timing entries saved during a Lighthouse run and generates
  * a trace file that's readable in DevTools perf panel or chrome://tracing.
  *
- * input = LHR.json
- * output = LHR.timing.trace.json
+ * node lighthouse-core/scripts/generate-timing-trace.js latest-run/lhr.report.json
+ *
+ * input = lhr.json
+ * output = lhr.timing.trace.json
  */
 
+import fs from 'fs';
+import path from 'path';
+
+import {createTraceString} from '../lib/timing-trace-saver.js';
+
 /**
  * @param {string} msg
  */
@@ -45,7 +48,8 @@ function saveTraceFromCLI() {
   const lhrObject = JSON.parse(fs.readFileSync(filename, 'utf8'));
   const jsonStr = createTraceString(lhrObject);
 
-  const traceFilePath = `${filename}.timing.trace.json`;
+  const pathObj = path.parse(filename);
+  const traceFilePath = path.join(pathObj.dir, `${pathObj.name}.timing.trace.json`);
   fs.writeFileSync(traceFilePath, jsonStr, 'utf8');
   // eslint-disable-next-line no-console
   console.log(`

lighthouse-core/scripts/i18n/bake-ctc-to-lhl.js

@@ -8,9 +8,10 @@
 
 /* eslint-disable no-console */
 
-const fs = require('fs');
-const path = require('path');
-const {LH_ROOT} = require('../../../root.js');
+import fs from 'fs';
+import path from 'path';
+
+import {LH_ROOT, readJson} from '../../../root.js';
 
 /**
  * @typedef CtcMessage
@@ -102,9 +103,7 @@ function bakePlaceholders(messages) {
 function loadCtcStrings(file) {
   if (!file.endsWith('.ctc.json')) throw new Error('Can only load ctc files');
 
-  const rawdata = fs.readFileSync(file, 'utf8');
-  const messages = JSON.parse(rawdata);
-  return messages;
+  return readJson(file);
 }
 
 /**
@@ -137,7 +136,7 @@ function collectAndBakeCtcStrings(dir) {
   return lhlFilenames;
 }
 
-module.exports = {
+export {
   collectAndBakeCtcStrings,
   bakePlaceholders,
 };

lighthouse-core/scripts/i18n/collect-strings.js

@@ -8,17 +8,21 @@
 
 /* eslint-disable no-console, max-len */
 
-const fs = require('fs');
-const glob = require('glob');
-const path = require('path');
-const expect = require('expect');
-const tsc = require('typescript');
-const MessageParser = require('intl-messageformat-parser').default;
-const Util = require('../../../lighthouse-core/util-commonjs.js');
-const {collectAndBakeCtcStrings} = require('./bake-ctc-to-lhl.js');
-const {pruneObsoleteLhlMessages} = require('./prune-obsolete-lhl-messages.js');
-const {countTranslatedMessages} = require('./count-translated.js');
-const {LH_ROOT} = require('../../../root.js');
+import fs from 'fs';
+import path from 'path';
+
+import glob from 'glob';
+import expect from 'expect';
+import tsc from 'typescript';
+import MessageParser from 'intl-messageformat-parser';
+import esMain from 'es-main';
+
+import Util from '../../../lighthouse-core/util-commonjs.js';
+import {collectAndBakeCtcStrings} from './bake-ctc-to-lhl.js';
+import {pruneObsoleteLhlMessages} from './prune-obsolete-lhl-messages.js';
+import {countTranslatedMessages} from './count-translated.js';
+import {LH_ROOT} from '../../../root.js';
+import {resolveModulePath} from '../esm-utils.js';
 
 const UISTRINGS_REGEX = /UIStrings = .*?\};\n/s;
 
@@ -30,7 +34,7 @@ const foldersWithStrings = [
   `${LH_ROOT}/lighthouse-core`,
   `${LH_ROOT}/report/renderer`,
   `${LH_ROOT}/lighthouse-treemap`,
-  path.dirname(require.resolve('lighthouse-stack-packs')) + '/packs',
+  path.dirname(resolveModulePath('lighthouse-stack-packs')) + '/packs',
 ];
 
 const ignoredPathComponents = [
@@ -722,14 +726,14 @@ async function main() {
 }
 
 // Test if called from the CLI or as a module.
-if (require.main === module) {
+if (esMain(import.meta)) {
   main().catch(err => {
     console.error(err.stack);
     process.exit(1);
   });
 }
 
-module.exports = {
+export {
   parseUIStrings,
   createPsuedoLocaleStrings,
   convertMessageToCtc,