js: Migrate to ESLint 9

Signed-off-by: Matt Strapp <matt@mattstrapp.net>

3 files changed, 46 insertions, 37 deletions

diff --git a/src/packages/eslint-config/eslint.library.config.js b/src/packages/eslint-config/eslint.library.config.js
new file mode 100644
index 0000000..e3c7866
--- /dev/null
+++ b/src/packages/eslint-config/eslint.library.config.js
@@ -0,0 +1,39 @@
+// @ts-check
+
+import globals from "globals";
+import eslint from "@eslint/js";
+import ts from "typescript-eslint";
+import prettier from "eslint-config-prettier";
+import turboPlugin from "eslint-plugin-turbo";
+
+import { resolve } from "node:path";
+
+const project = resolve(process.cwd(), "tsconfig.json");
+
+export default ts.config(
+  eslint.configs.recommended,
+  ...ts.configs.recommended,
+  prettier,
+  {
+    name: "eslint-config-turbo (recreated flat)",
+    plugins: {
+      turbo: { rules: turboPlugin.rules },
+    },
+    rules: {
+      "turbo/no-undeclared-env-vars": "error",
+    },
+  },
+  {
+    name: "library",
+    languageOptions: {
+      // parserOptions: {
+      //   project: resolve(process.cwd(), "tsconfig.json")
+      // },
+      globals: {
+        ...globals.browser,
+        ...globals.node,
+      },
+    },
+    ignores: ["build/", ".svelte-kit/", "dist/"],
+  },
+);
diff --git a/src/packages/eslint-config/library.js b/src/packages/eslint-config/library.js
deleted file mode 100644
index 9b59cc0..0000000
--- a/src/packages/eslint-config/library.js
+++ /dev/null
@@ -1,34 +0,0 @@
-const { resolve } = require("node:path");
-
-const project = resolve(process.cwd(), "tsconfig.json");
-
-/** @type {import("eslint").Linter.Config} */
-module.exports = {
-  extends: ["eslint:recommended", "prettier", "turbo"],
-  plugins: ["only-warn"],
-  globals: {
-    React: true,
-    JSX: true,
-  },
-  env: {
-    node: true,
-  },
-  settings: {
-    "import/resolver": {
-      typescript: {
-        project,
-      },
-    },
-  },
-  ignorePatterns: [
-    // Ignore dotfiles
-    ".*.js",
-    "node_modules/",
-    "dist/",
-  ],
-  overrides: [
-    {
-      files: ["*.js?(x)", "*.ts?(x)"],
-    },
-  ],
-};
diff --git a/src/packages/eslint-config/package.json b/src/packages/eslint-config/package.json
index ba005cf..a05970f 100644
--- a/src/packages/eslint-config/package.json
+++ b/src/packages/eslint-config/package.json
@@ -3,15 +3,19 @@
   "version": "0.0.0",
   "devDependencies": {
     "@typescript-eslint/eslint-plugin": "8.12.2",
-    "@typescript-eslint/parser": "8.12.2",
     "@vercel/style-guide": "6.0.0",
+    "@types/eslint": "^9.6.0",
+    "eslint": "^9.7.0",
     "eslint-config-prettier": "^9.1.0",
     "eslint-config-turbo": "^2.2.3",
     "eslint-plugin-only-warn": "^1.1.0",
-    "typescript": "^5.6.3"
+    "globals": "^15.0.0",
+    "typescript": "^5.6.3",
+    "typescript-eslint": "^8.0.0"
   },
   "files": [
-    "library.js"
+    "library.mjs"
   ],
+  "type": "module",
   "private": true
 }