chore: lint eleventy config file (#15904)

* chore: lint eleventy config file

* fix wrong override for eslint-plugin/prefer-output-null

* update `lint` command to exclude linting JS files in the docs dir

* add separate script from linting docs js files

* use internal mutliline comment style for sections

.eslintignore

@@ -1,6 +1,7 @@
 /build/**
 /coverage/**
 /docs/**
+!/docs/.eleventy.js
 /jsdoc/**
 /templates/**
 /tests/bench/**

.eslintrc.js

@@ -46,8 +46,7 @@ module.exports = {
         "internal-rules"
     ],
     extends: [
-        "eslint",
-        "plugin:eslint-plugin/recommended"
+        "eslint"
     ],
     parserOptions: {
         ecmaVersion: 2021
@@ -63,14 +62,6 @@ module.exports = {
         }
     },
     rules: {
-        "eslint-plugin/prefer-message-ids": "error",
-        "eslint-plugin/prefer-output-null": "error",
-        "eslint-plugin/prefer-placeholders": "error",
-        "eslint-plugin/prefer-replace-text": "error",
-        "eslint-plugin/report-message-format": ["error", "[^a-z].*\\.$"],
-        "eslint-plugin/require-meta-docs-description": "error",
-        "eslint-plugin/test-case-property-ordering": "error",
-        "eslint-plugin/test-case-shorthand-strings": "error",
         "internal-rules/multiline-comment-style": "error"
     },
     overrides: [
@@ -83,7 +74,15 @@ module.exports = {
         {
             files: ["lib/rules/*", "tools/internal-rules/*"],
             excludedFiles: ["index.js"],
+            extends: [
+                "plugin:eslint-plugin/rules-recommended"
+            ],
             rules: {
+                "eslint-plugin/prefer-message-ids": "error",
+                "eslint-plugin/prefer-placeholders": "error",
+                "eslint-plugin/prefer-replace-text": "error",
+                "eslint-plugin/report-message-format": ["error", "[^a-z].*\\.$"],
+                "eslint-plugin/require-meta-docs-description": "error",
                 "internal-rules/no-invalid-meta": "error"
             }
         },
@@ -94,6 +93,17 @@ module.exports = {
                 "eslint-plugin/require-meta-docs-url": ["error", { pattern: "https://eslint.org/docs/rules/{{name}}" }]
             }
         },
+        {
+            files: ["tests/lib/rules/*", "tests/tools/internal-rules/*"],
+            extends: [
+                "plugin:eslint-plugin/tests-recommended"
+            ],
+            rules: {
+                "eslint-plugin/prefer-output-null": "error",
+                "eslint-plugin/test-case-property-ordering": "error",
+                "eslint-plugin/test-case-shorthand-strings": "error"
+            }
+        },
         {
             files: ["tests/**/*"],
             env: { mocha: true },

.github/workflows/ci.yml

@@ -22,6 +22,11 @@ jobs:
       run: node Makefile checkRuleFiles
     - name: Check Licenses
       run: node Makefile checkLicenses
+    - name: Install Docs Packages
+      working-directory: docs
+      run: npm install
+    - name: Lint Docs JS Files
+      run: node Makefile lintDocsJS
 
   test_on_node:
     name: Test

Makefile.js

@@ -482,8 +482,17 @@ target.lint = function([fix = false] = []) {
     let errors = 0,
         lastReturn;
 
+    /*
+     * In order to successfully lint JavaScript files in the `docs` directory, dependencies declared in `docs/package.json`
+     * would have to be installed in `docs/node_modules`. In particular, eslint-plugin-node rules examine `docs/node_modules`
+     * when analyzing `require()` calls from CJS modules in the `docs` directory. Since our release process does not run `npm install`
+     * in the `docs` directory, linting would fail and break the release. Also, working on the main `eslint` package does not require
+     * installing dependencies declared in `docs/package.json`, so most contributors will not have `docs/node_modules` locally.
+     * Therefore, we add `--ignore-pattern docs` to exclude linting the `docs` directory from this command.
+     * There is a separate command `target.lintDocsJS` for linting JavaScript files in the `docs` directory.
+     */
     echo("Validating JavaScript files");
-    lastReturn = exec(`${ESLINT}${fix ? "--fix" : ""} .`);
+    lastReturn = exec(`${ESLINT}${fix ? "--fix" : ""} . --ignore-pattern docs`);
     if (lastReturn.code !== 0) {
         errors++;
     }
@@ -502,6 +511,21 @@ target.lint = function([fix = false] = []) {
     }
 };
 
+target.lintDocsJS = function([fix = false] = []) {
+    let errors = 0;
+
+    echo("Validating JavaScript files in the docs directory");
+    const lastReturn = exec(`${ESLINT}${fix ? "--fix" : ""} docs`);
+
+    if (lastReturn.code !== 0) {
+        errors++;
+    }
+
+    if (errors) {
+        exit(1);
+    }
+};
+
 target.fuzz = function({ amount = 1000, fuzzBrokenAutofixes = false } = {}) {
     const fuzzerRunner = require("./tools/fuzzer-runner");
     const fuzzResults = fuzzerRunner.run({ amount, fuzzBrokenAutofixes });