refactor: eslint config approach

Author: Belco90

eslint.config.mjs

@@ -4,35 +4,38 @@ import { fixupConfigRules } from '@eslint/compat';
 import { FlatCompat } from '@eslint/eslintrc';
 import js from '@eslint/js';
 import { defineConfig, globalIgnores } from 'eslint/config';
+import prettierConfig from 'eslint-config-prettier/flat';
+import jest from 'eslint-plugin-jest';
+import * as jestFormatting from 'eslint-plugin-jest-formatting';
 import globals from 'globals';
 import tseslint from 'typescript-eslint';
 
 const compat = new FlatCompat({
 	baseDirectory: import.meta.dirname,
-	recommendedConfig: js.configs.recommended,
 });
 
 const config = defineConfig(
+	js.configs.recommended,
+	tseslint.configs.recommendedTypeChecked,
 	{
+		name: 'Language options',
 		languageOptions: {
 			globals: {
-				...globals.es2019,
+				...globals.node,
+			},
+			parser: tseslint.parser,
+			parserOptions: {
+				projectService: true,
+				tsconfigRootDir: import.meta.dirname,
 			},
 		},
-
-		extends: fixupConfigRules(
-			compat.extends(
-				'eslint:recommended',
-				'plugin:import/recommended',
-				'plugin:jest/recommended',
-				'plugin:jest-formatting/recommended',
-				'prettier'
-			)
-		),
+	},
+	{
+		// TODO: replace import with import-x
+		name: 'Import plugin config',
+		extends: fixupConfigRules(compat.extends('plugin:import/recommended')),
 
 		rules: {
-			'max-lines-per-function': 'off',
-
 			'import/order': [
 				'warn',
 				{
@@ -55,54 +58,84 @@ const config = defineConfig(
 		},
 	},
 	{
-		files: ['**/*.ts'],
-
-		languageOptions: {
-			parser: tseslint.parser,
-			parserOptions: {
-				project: './tsconfig.eslint.json',
-				tsconfigRootDir: import.meta.dirname,
-			},
-		},
-
-		extends: fixupConfigRules(
-			compat.extends(
-				'plugin:@typescript-eslint/recommended',
-				'plugin:@typescript-eslint/recommended-type-checked',
-				'plugin:import/typescript'
-			)
-		),
-
+		name: 'Rules overrides for all files',
 		rules: {
-			'@typescript-eslint/explicit-function-return-type': 'off',
+			// Base
+			'max-lines-per-function': 'off',
 
+			// TypeScript
+			'@typescript-eslint/explicit-function-return-type': 'off',
 			'@typescript-eslint/no-unused-vars': [
 				'warn',
 				{
 					argsIgnorePattern: '^_',
 				},
 			],
-
 			'@typescript-eslint/no-use-before-define': 'off',
+		},
+	},
+	{
+		name: 'Rule overrides for TypeScript files',
+		files: ['**/*.ts', '**/*.mts'],
+		rules: {
+			// Import
+			// Rules enabled by `import/recommended` but are better handled by
+			// TypeScript and @typescript-eslint.
 			'import/default': 'off',
 			'import/export': 'off',
 			'import/namespace': 'off',
 			'import/no-unresolved': 'off',
 		},
-
-		settings: {
-			'import/resolver': {
-				node: {
-					extensions: ['.js', '.ts'],
-				},
-
-				typescript: {
-					alwaysTryTypes: true,
-				},
-			},
+	},
+	// {
+	// 	files: ['**/*.ts'],
+	//
+	// 	extends: fixupConfigRules(
+	// 		compat.extends(
+	// 			'plugin:import/typescript'
+	// 		)
+	// 	),
+	//
+	// 	rules: {
+	// 		'import/default': 'off',
+	// 		'import/export': 'off',
+	// 		'import/namespace': 'off',
+	// 		'import/no-unresolved': 'off',
+	// 	},
+	//
+	// 	settings: {
+	// 		'import/resolver': {
+	// 			node: {
+	// 				extensions: ['.js', '.ts'],
+	// 			},
+	//
+	// 			typescript: {
+	// 				alwaysTryTypes: true,
+	// 			},
+	// 		},
+	// 	},
+	// },
+	{
+		name: 'Jest config',
+		files: ['**/*.test.ts', '**/*.test.js'],
+		...jest.configs['flat/recommended'],
+		...jestFormatting.configs['flat/recommended'],
+	},
+	{
+		name: 'Plain JS',
+		files: ['**/*.js', '**/*.mjs', '**/*.cjs'],
+		extends: [tseslint.configs.disableTypeChecked],
+	},
+	{
+		name: 'Config files',
+		files: ['./*.js', './*.cjs', './*.mjs', '**/*.config.*js'],
+		rules: {
+			'@typescript-eslint/no-require-imports': 'off',
+			'import/no-unresolved': 'off',
 		},
 	},
-	globalIgnores(['**/coverage/', '**/dist/'])
+	globalIgnores(['**/coverage/', '**/dist/']),
+	prettierConfig // must always be the last one
 );
 
 export default config;

package.json

@@ -66,8 +66,6 @@
 		"@swc/jest": "^0.2.37",
 		"@types/jest": "^29.5.14",
 		"@types/node": "^22.9.3",
-		"@typescript-eslint/eslint-plugin": "^8.43.0",
-		"@typescript-eslint/parser": "^8.43.0",
 		"@typescript-eslint/rule-tester": "^8.43.0",
 		"del-cli": "^6.0.0",
 		"eslint": "^9.35.0",

pnpm-lock.yaml

@@ -1,5 +1,5 @@
-import tsESLintParser from '@typescript-eslint/parser';
 import { RuleTester, RunTests } from '@typescript-eslint/rule-tester';
+import { parser } from 'typescript-eslint';
 
 import { TestingLibraryPluginRuleModule } from '../../lib/utils';
 
@@ -35,7 +35,7 @@ class TestingLibraryRuleTester extends RuleTester {
 export const createRuleTester = () =>
 	new TestingLibraryRuleTester({
 		languageOptions: {
-			parser: tsESLintParser,
+			parser,
 			parserOptions: {
 				ecmaFeatures: {
 					jsx: true,

tests/lib/test-utils.ts

@@ -1,4 +1,4 @@
 {
 	"extends": "./tsconfig.json",
-	"exclude": ["./tests/**/*.ts"]
+	"exclude": ["./tests", "./tools"]
 }

tsconfig.build.json

@@ -16,5 +16,5 @@
 		"outDir": "dist",
 		"sourceMap": false
 	},
-	"include": ["./lib/**/*.ts", "./tests/**/*.ts"]
+	"include": ["**/*.ts"]
 }