loader: test search module

PR-URL: https://github.com/nodejs/node/pull/16795
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

test/es-module/test-esm-loader-search.js

@@ -0,0 +1,18 @@
+'use strict';
+// Flags: --expose-internals
+
+// This test ensures that search throws errors appropriately
+
+const common = require('../common');
+
+const search = require('internal/loader/search');
+const errors = require('internal/errors');
+
+common.expectsError(
+  () => search('target', undefined),
+  {
+    code: 'ERR_MISSING_MODULE',
+    type: errors.Error,
+    message: 'Cannot find module target'
+  }
+);