diff --git a/test/file.ts b/test/file.ts
index da986873..84337b28 100644
--- a/test/file.ts
+++ b/test/file.ts
@@ -4,3 +4,6 @@
  * Licensed under the BSD 3-Clause license.
  * For full license text, see LICENSE.txt file in the repo root or https://opensource.org/licenses/BSD-3-Clause
  */
+
+// for tests that use the TS compiler, this file needs to exist.
+// see https://typescript-eslint.io/custom-rules/#testing-typed-rules