feat: migrate to flat config 🚀

BREAKING CHANGE: The ruleset has been migrated to ESLint flat config format and is therefore not compatible with ESLint v7 and using it with v8 requires a feature flag (`ESLINT_USE_FLAT_CONFIG=true`). Project configuration will also need to be completely reworked to use the new ruleset.

.vscode/settings.json

@@ -4,7 +4,6 @@
     "**/.git": true,
     "**/.DS_Store": true,
     "**/*.log": true,
-    "**/node_modules": true,
     ".eslintcache": true
   },
   // Custom Application window title ❤️
@@ -19,10 +18,10 @@
   "javascript.format.enable": false,
   "typescript.format.enable": false,
   // Enable ESLint and its auto-fixer
-  "editor.formatOnSave": false,
   "editor.codeActionsOnSave": {
     "source.fixAll.eslint": "always"
   },
   "eslint.lintTask.enable": true,
   "eslint.lintTask.options": ".",
+  "eslint.experimental.useFlatConfig": true,
 }

eslint.config.js

@@ -0,0 +1,26 @@
+import node from './packages/eslint-config-node/index.mjs'
+import optional from './packages/eslint-config-node/optional.mjs'
+import style from './packages/eslint-config-node/style.mjs'
+
+/** @type {import("eslint").Linter.FlatConfig} */
+const common = {
+  linterOptions: {
+    reportUnusedDisableDirectives: true,
+  },
+  ignores: [
+    'node_modules',
+    '!.*.js',
+  ],
+}
+
+/** @type {Array<import("eslint").Linter.FlatConfig>} */
+const configs = [
+  common,
+  node,
+  optional,
+  style,
+  { files: ['**/*.js'], languageOptions: { sourceType: 'commonjs' } },
+  { files: ['**/*.mjs', 'eslint.config.js'], languageOptions: { sourceType: 'module' } },
+]
+
+export default configs

makefile

@@ -2,6 +2,8 @@
 SHELL := sh
 export PATH := bin/:node_modules/.bin/:$(PATH)
 export NODE_OPTIONS := --trace-deprecation
+# Enable ESLint Flat Config support
+export ESLINT_USE_FLAT_CONFIG=true
 
 # On CI servers, use the `npm ci` installer to avoid introducing changes to the package-lock.json
 # On developer machines, prefer the generally more flexible `npm install`. 💪