Upgrade eslint to latest

eslint.config.mjs

@@ -0,0 +1,27 @@
+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 [...compat.extends("eslint:recommended"), {
+  languageOptions: {
+    globals: {
+      ...globals.node,
+    },
+  },
+
+  rules: {
+    indent: ["error", 2],
+    "linebreak-style": ["error", "unix"],
+    semi: ["error", "always"],
+  },
+}];

package.json

@@ -10,7 +10,7 @@
     "node": ">=18"
   },
   "scripts": {
-    "pretest": "eslint img.js test/**.js",
+    "pretest": "eslint img.js src/**.js test/**.js",
     "test": "ava --no-worker-threads",
     "sample": "cd sample && node sample.js"
   },
@@ -49,8 +49,11 @@
   "devDependencies": {
     "@11ty/eleventy": "^3.0.0",
     "@11ty/eleventy-plugin-webc": "^0.11.2",
-    "ava": "^6.1.3",
-    "eslint": "^8.56.0",
+    "@eslint/eslintrc": "^3.2.0",
+    "@eslint/js": "^9.15.0",
+    "ava": "^6.2.0",
+    "eslint": "^9.15.0",
+    "globals": "^15.12.0",
     "pixelmatch": "^5.3.0"
   },
   "ava": {