fix: type errors of typescript-eslint

packages/core/src/env.d.ts

@@ -1,5 +1,7 @@
+import type { ESLint, Linter } from 'eslint';
+
 /**
- * @see {@link https://github.com/sindresorhus/globals}
+ * @see {@link https://github.com/sindresorhus/globals github repository}
  * @summary Global identifiers from different Javascript environments
  * ---
  * **Note:**
@@ -20,3 +22,48 @@ declare module 'globals' {
 	};
 	export default globals;
 }
+
+/**
+ * @see {@link https://www.npmjs.com/package/@typescript-eslint/eslint-plugin npm package}
+ * @summary An ESLint plugin which provides lint rules for TypeScript codebases.
+ *
+ * ---
+ * **Note:** Types in this project where overridden to be compatible with ESLint new flat
+ * config types. ESlint already has backwards compatibility for plugins not created in the
+ * new flat config.
+ */
+declare module '@typescript-eslint/eslint-plugin' {
+	interface typescriptEslintPlugin extends ESLint.Plugin {
+		configs: {
+			recommended: {
+				rules: Linter.RulesRecord
+			}
+			'recommended-requiring-type-checking': {
+				rules: Linter.RulesRecord
+			}
+			'eslint-recommended': {
+				rules: Linter.RulesRecord
+			}
+			strict: {
+				rules: Linter.RulesRecord
+			}
+		}
+	}
+	const plugin: typescriptEslintPlugin;
+	export default plugin;
+}
+
+/**
+ * @see {@link https://www.npmjs.com/package/@typescript-eslint/parser npm package}
+ * @summary An ESLint parser which leverages TypeScript ESTree to allow for ESLint
+ * to lint TypeScript source code.
+ *
+ * ---
+ * **Note:** Types in this project where overridden to be compatible with ESLint new flat
+ * config types. ESlint already has backwards compatibility for parsers not created in the
+ * new flat config.
+ */
+declare module '@typescript-eslint/parser' {
+	const parser: Linter.ParserModule;
+	export default parser;
+}

packages/core/src/index.js

@@ -24,22 +24,16 @@ export function defineConfig(userConfig) {
 		{
 			files: ['**/*.js', '**/*.ts'],
 			plugins: {
-				// @ts-expect-error The `@typescript-eslint/eslint-plugin` package doesn't export
-				// a correct type as default. But this still works because of backwards-compatibility of eslint.
 				'@typescript-eslint': tsEslint,
 			},
 			languageOptions: {
 				sourceType: 'module',
-				// @ts-expect-error The `@typescript-eslint/parser` package doesn't export a correct type as default.
-				// (see `plugins['@typescript-eslint']` option/property error for more info)
 				parser: tsParser,
 				parserOptions: {
 					project: userConfig.tsconfig,
 					tsconfigRootDir: process.cwd(),
 				},
 			},
-			// @ts-expect-error The `@typescript-eslint/eslint-plugin` package doesn't export
-			// rules as `RulesRecord` type.
 			rules: {
 				...tsEslint.configs.recommended.rules,
 				...tsEslint.configs['recommended-requiring-type-checking'].rules,