style: ignore unused variables which begin with an underscore

.eslintrc.js

@@ -10,6 +10,13 @@ module.exports = {
   extends: ['eslint:recommended', 'plugin:@typescript-eslint/recommended'],
   rules: {
     'prettier/prettier': 'error',
+    '@typescript-eslint/no-unused-vars': [
+      'warn',
+      {
+        argsIgnorePattern: '^_'
+      }
+    ],
+
     '@typescript-eslint/no-var-requires': 'off'
   }
 };

util/error-middleware.js

@@ -1,4 +1,4 @@
-async function middleware(err, req, res, next) {
+async function middleware(err, req, res, _next) {
   console.log('ERROR', err);
   res.status(500).send({ status: 'error', reason: 'internal-error' });
 }