Migrate typescript-eslint to flat config (#42)

Author: steverep

eslint.config.js

@@ -1,39 +1,28 @@
-import { FlatCompat } from "@eslint/eslintrc";
+// @ts-check
 import eslintJS from "@eslint/js";
-import typescriptParser from "@typescript-eslint/parser";
 import eslintConfigPrettier from "eslint-config-prettier";
 import globals from "globals";
-import { dirname } from "path";
-import { fileURLToPath } from "url";
+import eslintTS from "typescript-eslint";
 
 const allFiles = "**/*.?(c|m){js,ts}";
 const jsFiles = "**/*.?(c|m)js";
 const commonFiles = "**/*.c{js,ts}";
 
-const rootDir = dirname(fileURLToPath(import.meta.url));
-const compat = new FlatCompat({ baseDirectory: rootDir });
-
-export default [
+export default eslintTS.config(
   { ignores: [".yarn/", ".pnp.*", "**/dist/"] },
-  { files: [allFiles], ...eslintJS.configs.recommended },
-  ...compat
-    .extends(
-      "plugin:@typescript-eslint/recommended-type-checked",
-      "plugin:@typescript-eslint/stylistic-type-checked",
-    )
-    .map((config) => ({ files: [allFiles], ...config })),
-  ...compat
-    .extends("plugin:@typescript-eslint/disable-type-checked")
-    .map((config) => ({ files: [jsFiles], ...config })),
-  { files: [allFiles], ...eslintConfigPrettier },
   {
     files: [allFiles],
+    extends: [
+      eslintJS.configs.recommended,
+      ...eslintTS.configs.recommendedTypeChecked,
+      ...eslintTS.configs.stylisticTypeChecked,
+      eslintConfigPrettier,
+    ],
     languageOptions: {
       ecmaVersion: "latest",
       sourceType: "module",
       globals: globals.nodeBuiltin,
-      // Options specific to @typescript-eslint/parser
-      parser: typescriptParser,
+      parser: eslintTS.parser,
       parserOptions: {
         allowAutomaticSingleRunInference: true,
         ecmaVersion: "latest",
@@ -44,6 +33,10 @@ export default [
       reportUnusedDisableDirectives: true,
     },
   },
+  {
+    files: [jsFiles],
+    extends: [eslintTS.configs.disableTypeChecked],
+  },
   {
     files: [commonFiles],
     languageOptions: {
@@ -58,4 +51,4 @@ export default [
       "@typescript-eslint/require-await": "off",
     },
   },
-];
+);

package.json

@@ -64,20 +64,16 @@
   },
   "devDependencies": {
     "@babel/runtime": "7.24.4",
-    "@eslint/eslintrc": "3.0.2",
     "@eslint/js": "8.57.0",
     "@types/babel__core": "7.20.5",
     "@types/babel__plugin-transform-runtime": "7.9.5",
     "@types/babel__preset-env": "7.9.6",
     "@types/chai": "4.3.14",
     "@types/chai-jest-snapshot": "1.3.8",
     "@types/eslint-config-prettier": "6.11.3",
-    "@types/eslint__eslintrc": "2.1.1",
     "@types/eslint__js": "8.42.3",
     "@types/mocha": "10.0.6",
     "@types/node": "20.12.7",
-    "@typescript-eslint/eslint-plugin": "7.6.0",
-    "@typescript-eslint/parser": "7.6.0",
     "chai": "5.1.0",
     "chai-jest-snapshot": "2.0.0",
     "eslint": "8.57.0",
@@ -87,6 +83,7 @@
     "prettier": "3.2.5",
     "ts-node": "10.9.2",
     "typescript": "5.4.5",
+    "typescript-eslint": "7.7.0",
     "webpack": "5.91.0"
   }
 }