test: adds unit test for utensils

(they were already covered in an integration test, but having it explicitly in a UT is useful

src/utensils.test.ts

@@ -0,0 +1,19 @@
+import { equal } from "node:assert/strict";
+import { describe, it } from "node:test";
+import { isEmailIshUsername } from "./utensils";
+
+describe("utensils - isEmailIshUsername", () => {
+  it("should return true for email-like usernames", () => {
+    equal(isEmailIshUsername("[email protected]"), true);
+    equal(isEmailIshUsername("[email protected]"), true);
+    equal(isEmailIshUsername("[email protected]"), true);
+  });
+
+  it("should return false for non-email-like usernames", () => {
+    equal(isEmailIshUsername("john"), false);
+    equal(isEmailIshUsername("jane.doe"), false);
+    equal(isEmailIshUsername("jane.doe+test"), false);
+    equal(isEmailIshUsername("john@"), false);
+    equal(isEmailIshUsername("@example.com"), false);
+  });
+});