chore(eslint): migrate to eslint 9

.github/dependabot.yml

@@ -1,14 +1,22 @@
 # To get started with Dependabot version updates, you'll need to specify which
 # package ecosystems to update and where the package manifests are located.
 # Please see the documentation for all configuration options:
-# https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+# https://docs.github.com/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file
 
 version: 2
 updates:
   - package-ecosystem: 'npm'
     directory: '/'
     schedule:
       interval: 'daily'
+    groups:
+      eslint:
+        patterns:
+          - '@eslint/*'
+      prettier:
+        patterns:
+          - prettier
+          - eslint-plugin-prettier
 
   - package-ecosystem: 'github-actions'
     directory: '/'

eslint.config.mjs

@@ -0,0 +1,40 @@
+import prettier from 'eslint-plugin-prettier';
+import globals from 'globals';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import js from '@eslint/js';
+import { FlatCompat } from '@eslint/eslintrc';
+import { includeIgnoreFile } from '@eslint/compat';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const gitignorePath = path.resolve(__dirname, '.gitignore');
+
+const compat = new FlatCompat({
+  baseDirectory: __dirname,
+  recommendedConfig: js.configs.recommended,
+  allConfig: js.configs.all,
+});
+
+export default [
+  includeIgnoreFile(gitignorePath),
+
+  ...compat.extends('eslint:recommended'),
+
+  {
+    plugins: {
+      prettier,
+    },
+
+    languageOptions: {
+      globals: {
+        ...globals.jest,
+        ...globals.node,
+      },
+    },
+
+    rules: {
+      'prettier/prettier': 'error',
+    },
+  },
+];

package.json

@@ -25,8 +25,12 @@
     "request": "2.88.2"
   },
   "devDependencies": {
+    "@eslint/compat": "1.2.0",
+    "@eslint/eslintrc": "3.1.0",
+    "@eslint/js": "9.12.0",
     "eslint": "9.12.0",
     "eslint-plugin-prettier": "5.2.1",
+    "globals": "15.10.0",
     "jest": "29.7.0",
     "nock": "13.5.5",
     "nodemon": "3.1.7",

routes/v1.js

@@ -52,6 +52,7 @@ module.exports = router.all('/cors', (req, res) => {
             try {
               contentType.parse(fieldValue);
               // TypeError: invalid media type
+              // eslint-disable-next-line no-unused-vars
             } catch (error) {
               res.status(500);
               res.send('Invalid "Content-Type" parameter.');