migrate to eslint 9 conf (#213)

.github/workflows/node.js.yml

@@ -24,6 +24,7 @@ jobs:
         node-version: ${{ matrix.node-version }}
     - run: npm ci
     - run: npm i ol@${{ matrix.ol-version }}
+    - run: npm run lint
     - run: npm run build
     - run: npm test
 

eslint.config.mjs

@@ -0,0 +1,81 @@
+import mocha from 'eslint-plugin-mocha';
+import globals from 'globals';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import js from '@eslint/js';
+import { FlatCompat } from '@eslint/eslintrc';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const compat = new FlatCompat({
+    baseDirectory: __dirname,
+    recommendedConfig: js.configs.recommended,
+    allConfig: js.configs.all
+});
+
+export default [{
+    ignores: ['test/XMLHttpRequest.cjs'],
+},
+...compat.extends(
+    'eslint:recommended',
+    'plugin:@typescript-eslint/eslint-recommended',
+    'plugin:@typescript-eslint/recommended',
+).map(config => ({
+    ...config,
+    files: ['**/*.ts'],
+})),
+{
+    plugins: {
+        mocha,
+    },
+
+    languageOptions: {
+        globals: {
+            ...globals.browser,
+            ...globals.commonjs,
+            ...globals.node,
+            ...globals.mocha,
+        },
+
+        ecmaVersion: 2017,
+        sourceType: 'module',
+    },
+
+    rules: {
+        'no-unused-vars': 'off',
+
+        '@typescript-eslint/no-unused-vars': ['warn', {
+            argsIgnorePattern: '^_',
+            varsIgnorePattern: '^_',
+            caughtErrorsIgnorePattern: '^_',
+        }],
+
+        quotes: ['error', 'single'],
+        semi: ['error', 'always'],
+        'mocha/no-exclusive-tests': 'error',
+    },
+
+    files: ['**/*.ts'],
+},
+...compat.extends('eslint:recommended').map(config => ({
+    ...config,
+    files: ['**/*.js', '**/*.cjs'],
+})),
+{
+    files: ['test/*.ts'],
+
+    rules: {
+        '@typescript-eslint/no-unused-expressions': 'off',
+    },
+},
+{
+    files: ['**/*.cjs'],
+
+    languageOptions: {
+        sourceType: 'commonjs',
+    },
+
+    rules: {
+        '@typescript-eslint/no-require-imports': 'off'
+    },
+}];

package.json

@@ -48,6 +48,8 @@
     "ol": ">=10.0.0 <10.3.0"
   },
   "devDependencies": {
+    "@eslint/eslintrc": "^3.1.0",
+    "@eslint/js": "^9.11.0",
     "@rollup/plugin-typescript": "^11.1.5",
     "@types/chai": "^4.3.11",
     "@types/chai-spies": "^1.0.6",
@@ -69,6 +71,7 @@
     "eslint": "^9.8.0",
     "eslint-plugin-mocha": "^10.2.0",
     "gh-pages": "^6.1.1",
+    "globals": "^15.9.0",
     "html-loader": "^5.0.0",
     "html-webpack-plugin": "^5.6.0",
     "link": "^2.1.0",