chore: add additional EsLint rule (#147)

Author: Lightning00Blade

eslint.config.mjs

@@ -5,26 +5,59 @@
  */
 
 import js from '@eslint/js';
+import stylisticPlugin from '@stylistic/eslint-plugin';
+import {defineConfig, globalIgnores} from 'eslint/config';
+import importPlugin from 'eslint-plugin-import';
 import globals from 'globals';
 import tseslint from 'typescript-eslint';
-import {defineConfig, globalIgnores} from 'eslint/config';
-import checkLicensePlugin from './scripts/eslint_rules/check-license-plugin.js';
+
+import localPlugin from './scripts/eslint_rules/local-plugin.js';
 
 export default defineConfig([
   globalIgnores(['**/node_modules', '**/build/']),
+  importPlugin.flatConfigs.typescript,
   {
-    files: ['**/*.{js,mjs,cjs,ts,mts,cts}'],
-    plugins: {js},
+    languageOptions: {
+      ecmaVersion: 'latest',
+      sourceType: 'module',
+
+      globals: {
+        ...globals.node,
+      },
+
+      parserOptions: {
+        projectService: {
+          allowDefaultProject: ['.prettierrc.cjs', 'eslint.config.mjs'],
+        },
+      },
+
+      parser: tseslint.parser,
+    },
+
+    plugins: {
+      js,
+      '@local': localPlugin,
+      '@typescript-eslint': tseslint.plugin,
+      '@stylistic': stylisticPlugin,
+    },
+
+    settings: {
+      'import/resolver': {
+        typescript: true,
+      },
+    },
+
     extends: ['js/recommended'],
   },
+  tseslint.configs.recommended,
+  tseslint.configs.stylistic,
   {
-    files: ['**/*.{js,mjs,cjs,ts,mts,cts}'],
-    languageOptions: {globals: globals.node},
-  },
-  {plugins: {checkLicensePlugin}},
-  {
+    name: 'TypeScript rules',
     rules: {
-      'checkLicensePlugin/check-license': 'error',
+      '@local/check-license': 'error',
+
+      'no-undef': 'off',
+      'no-unused-vars': 'off',
       '@typescript-eslint/no-unused-vars': [
         'error',
         {
@@ -38,7 +71,52 @@ export default defineConfig([
           ignoreRestArgs: true,
         },
       ],
+      // This optimizes the dependency tracking for type-only files.
+      '@typescript-eslint/consistent-type-imports': 'error',
+      // So type-only exports get elided.
+      '@typescript-eslint/consistent-type-exports': 'error',
+      // Prefer interfaces over types for shape like.
+      '@typescript-eslint/consistent-type-definitions': ['error', 'interface'],
+      '@typescript-eslint/array-type': [
+        'error',
+        {
+          default: 'array-simple',
+        },
+      ],
+      '@typescript-eslint/no-floating-promises': 'error',
+
+      'import/order': [
+        'error',
+        {
+          'newlines-between': 'always',
+
+          alphabetize: {
+            order: 'asc',
+            caseInsensitive: true,
+          },
+        },
+      ],
+
+      'import/no-cycle': [
+        'error',
+        {
+          maxDepth: Infinity,
+        },
+      ],
+
+      'import/enforce-node-protocol-usage': ['error', 'always'],
+
+      '@stylistic/function-call-spacing': 'error',
+      '@stylistic/semi': 'error',
+    },
+  },
+  {
+    name: 'Tests',
+    files: ['**/*.test.ts'],
+    rules: {
+      // With the Node.js test runner, `describe` and `it` are technically
+      // promises, but we don't need to await them.
+      '@typescript-eslint/no-floating-promises': 'off',
     },
   },
-  tseslint.configs.recommended,
 ]);