scripts/test/run_lint_check_js.mjs

// Copyright 2020 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Use V8's code cache to speed up instantiation time.
await import('v8-compile-cache');

import path from 'path';
import {ESLint} from 'eslint';
import { fileURLToPath } from 'url';

import yargs from 'yargs';

// False positive from the ESLint rule: crbug.com/1319352
// eslint-disable-next-line rulesdir/es_modules_import
import {hideBin} from 'yargs/helpers';

const flags = yargs(hideBin(process.argv)).option('fix', {
  type: 'boolean',
  default: true,
  describe: 'If to run ESLint in fix mode',
}).parse();

const shouldFix = flags.fix === true;

if(!shouldFix) {
  console.log('[ESLint]: fix is disabled; no errors will be autofixed.');
}

const __dirname = path.dirname(fileURLToPath(import.meta.url));

const ROOT_DIRECTORY = path.join(__dirname, '..', '..');
const FRONT_END_DIRECTORY = path.join(ROOT_DIRECTORY, 'front_end');
const INSPECTOR_OVERLAY_DIRECTORY = path.join(ROOT_DIRECTORY, 'inspector_overlay');
const TEST_DIRECTORY = path.join(ROOT_DIRECTORY, 'test');
const SCRIPTS_DIRECTORY = path.join(ROOT_DIRECTORY, 'scripts');

const DEFAULT_DIRECTORIES_TO_LINT =
    [FRONT_END_DIRECTORY, INSPECTOR_OVERLAY_DIRECTORY, TEST_DIRECTORY, SCRIPTS_DIRECTORY];

const eslintignorePath = path.join(ROOT_DIRECTORY, '.eslintignore');

// Yargs gathers up any non-flag arguments into the `_` property.
// npm run check-lint-js foo => flags._ === ['foo']
let directoriesOrFilesToLint = flags._;

if (directoriesOrFilesToLint.length === 0) {
  directoriesOrFilesToLint = DEFAULT_DIRECTORIES_TO_LINT;
}

const cli = new ESLint({
  extensions: ['.js', '.ts'],
  ignorePath: eslintignorePath,
  fix: shouldFix,
});

// We filter out certain files in the `.eslintignore`. However, ESLint produces warnings
// when you include a particular file that is ignored. This means that if you edit a file
// that is directly ignored in the `.eslintignore`, ESLint would report a failure.
// This was originally reported in https://github.com/eslint/eslint/issues/9977
// The suggested workaround is to use the CLIEngine to pre-emptively filter out these
// problematic paths.
const filteredFilesToLint = [];
for (const path of directoriesOrFilesToLint) {
  if (!(await cli.isPathIgnored(path))) {
    filteredFilesToLint.push(path);
  }
}

const results = await cli.lintFiles(filteredFilesToLint);

// Write fixes to the filesystem
if (shouldFix) {
  await ESLint.outputFixes(results);
}

const formatter = await cli.loadFormatter('stylish');
console.log(formatter.format(results));

const hasProblems = results.find(report => report.errorCount + report.warningCount > 0);
process.exit(hasProblems ? 1 : 0);