[lint] Improvements and fixes to linting

Rerun all files if `lit-analyzer` rules change. Add support for EsLint
cache - `npm run lint` delta first run vs second of over 2 min. Don't
run EsLint if all files are ignored.

Bug: none
Change-Id: I042ede01cf0fe6de63b066723e1dc61cae3f9dcc
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6213930
Auto-Submit: Nikolay Vitkov <[email protected]>
Reviewed-by: Benedikt Meurer <[email protected]>
Commit-Queue: Simon Zünd <[email protected]>
Reviewed-by: Simon Zünd <[email protected]>

Author: Lightning00Blade

.gitignore

@@ -48,3 +48,7 @@ test/perf/.generated
 /.vscode/settings.json
 /.vscode/tasks.json
 /.vscode/launch.json
+
+# Linters caches
+.eslintcache
+.stylelintcache

PRESUBMIT.py

@@ -292,6 +292,9 @@ def _CheckDevToolsLint(input_api, output_api):
                                '.stylelintrc.json'),
         input_api.os_path.join(input_api.PresubmitLocalPath(),
                                '.stylelintignore'),
+        # This file includes the LitAnalyzer rules
+        input_api.os_path.join(input_api.PresubmitLocalPath(),
+                               'tsconfig.json'),
         input_api.os_path.join(scripts_directory, 'test',
                                'run_lint_check.mjs'),
     ]

eslint.config.mjs

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+/* eslint-disable import/no-default-export */
 import typescriptPlugin from '@typescript-eslint/eslint-plugin';
 import mochaPlugin from 'eslint-plugin-mocha';
 import rulesdirPlugin from 'eslint-plugin-rulesdir';
@@ -26,6 +27,10 @@ export default [
   {
     name: 'Ignore list',
     ignores: [
+      // Git submodules that are not in third_party
+      'build/',
+      'buildtools/',
+
       'front_end/diff/diff_match_patch.jD',
       'front_end/models/javascript_metadata/NativeFunctions.js',
       // All of these scripts are auto-generated so don't lint them.
@@ -84,6 +89,10 @@ export default [
       },
     },
 
+    linterOptions: {
+      reportUnusedDisableDirectives: 'error',
+    },
+
     rules: {
       // syntax preferences
       '@stylistic/quotes': [
@@ -272,11 +281,11 @@ export default [
       parserOptions: {
         allowAutomaticSingleRunInference: true,
         project: join(
-            import.meta.dirname,
-            'config',
-            'typescript',
-            'tsconfig.eslint.json',
-            ),
+          import.meta.dirname,
+          'config',
+          'typescript',
+          'tsconfig.eslint.json',
+        ),
       },
     },
 
@@ -465,12 +474,12 @@ export default [
         {
           // Enforce that any import of models/trace/trace.js names the import Trace.
           modulePath: join(
-              import.meta.dirname,
-              'front_end',
-              'models',
-              'trace',
-              'trace.js',
-              ),
+            import.meta.dirname,
+            'front_end',
+            'models',
+            'trace',
+            'trace.js',
+          ),
           importName: 'Trace',
         },
       ],

scripts/test/run_lint_check.mjs

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import { loadESLint } from 'eslint';
+import { ESLint } from 'eslint';
 import stylelint from 'stylelint';
 
 import { extname, join } from 'path';
@@ -44,25 +44,35 @@ if (!flags.fix) {
   console.log('[lint]: fix is disabled; no errors will be autofixed.');
 }
 
-async function runESLint(files) {
-  const EsLintFlat = await loadESLint({ useFlatConfig: true });
-  const cli = new EsLintFlat({
+async function runESLint(scriptFiles) {
+  const cli = new ESLint({
     cwd: join(import.meta.dirname, '..', '..'),
     fix: flags.fix,
+    cache: true,
   });
 
-  // We filter out certain files in the `.eslintignore`. However, ESLint produces warnings
+  // We filter out certain files in the `eslint.config.mjs` `Ignore list` entry.
+  // 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.
+  // that is directly ignored. 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 preemptively filter out these
   // problematic paths.
-  files = await Promise.all(
-    files.map(async file => {
-      return (await cli.isPathIgnored(file)) ? null : file;
-    }),
-  );
-  files = files.filter(file => file !== null);
+  const files = (
+    await Promise.all(
+      scriptFiles.map(async file => {
+        return (await cli.isPathIgnored(file)) ? null : file;
+      }),
+    )
+  ).filter(file => file !== null);
+
+  if (files.length === 0) {
+    // When an empty array is pass lint CWD
+    // This can happen only if we pass things that will
+    // be ignored by the above filter
+    // https://github.com/eslint/eslint/pull/17644
+    return true;
+  }
 
   const results = await cli.lintFiles(files);
 
@@ -79,7 +89,7 @@ async function runESLint(files) {
   }
 
   if (flags.fix) {
-    await EsLintFlat.outputFixes(results);
+    await ESLint.outputFixes(results);
   }
 
   const formatter = await cli.loadFormatter('stylish');
@@ -98,6 +108,8 @@ async function runStylelint(files) {
     fix: flags.fix,
     files,
     formatter: 'string',
+    cache: true,
+    allowEmptyInput: true,
   });
 
   if (report) {

third_party/i18n/collect-strings.js

@@ -1,5 +1,5 @@
 #!/usr/bin/env node
-/* eslint-disable no-console, max-len, rulesdir/check-license-header */
+/* eslint-disable no-console, rulesdir/check-license-header */
 
 /**
  * @license Copyright 2018 The Lighthouse Authors. All Rights Reserved.
@@ -604,12 +604,6 @@ function parseUIStrings(sourceStr) {
 /** @type {Map<string, string>} */
 const seenStrings = new Map();
 
-/** @type {number} */
-let collisions = 0;
-
-/** @type {Array<string>} */
-const collisionStrings = [];
-
 /** @type {Record<string, CtcMessage>} */
 const strings = {};
 
@@ -623,7 +617,7 @@ function collectAllStringsInDir(directory) {
   // If CWD is contains "third_party" (e.g. in a full Chromium checkout) then
   // *all* paths will be ignored. To avoid this, make the directory relative to
   // CWD.
-  directory = path.relative(process.cwd(), directory)
+  directory = path.relative(process.cwd(), directory);
   const files = glob.sync('**/*.{js,ts}', {
     cwd: directory,
     ignore: IGNORED_PATH_COMPONENTS,
@@ -685,10 +679,7 @@ function collectAllStringsInDir(directory) {
         if (seenId) {
           if (!strings[seenId].meaning) {
             strings[seenId].meaning = strings[seenId].meaning ?? strings[seenId].description;
-            collisions++;
           }
-          collisionStrings.push(ctc.message);
-          collisions++;
         }
       }
       seenStrings.set(ctc.message, messageKey);
@@ -721,6 +712,7 @@ if (require.main === module) {
     throw new Error('Provide at least one directory from which to collect strings!');
   }
   const directories = process.argv.slice(2);
+  /** @type {Record<string, CtcMessage>} */
   let collectedStrings = {};
   for (const directory of directories) {
     collectedStrings = {