From fcd12430b0d60f42502340027427ef6f5e5284bf Mon Sep 17 00:00:00 2001
From: ytj-zuel <15623621570>
Date: Mon, 6 Jul 2026 13:59:31 +0800
Subject: [PATCH] test: add unit tests for validString

Adds a small, focused, additive unit-test file (test/valid-string.test.ts).
No existing files are modified or removed. yarn test:ci passes locally.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 test/valid-string.test.ts | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 test/valid-string.test.ts

diff --git a/test/valid-string.test.ts b/test/valid-string.test.ts
new file mode 100644
index 00000000000..635d6e9826a
--- /dev/null
+++ b/test/valid-string.test.ts
@@ -0,0 +1,17 @@
+import { validString } from "../app/client/api";
+
+describe("validString", () => {
+  test("returns true for a non-empty string", () => {
+    expect(validString("a")).toBe(true);
+    expect(validString("  padded  ")).toBe(true);
+  });
+
+  test("returns false for an empty string", () => {
+    expect(validString("")).toBe(false);
+  });
+
+  test("returns false for null / undefined input", () => {
+    expect(validString(undefined as any)).toBe(false);
+    expect(validString(null as any)).toBe(false);
+  });
+});