diff --git a/tests/cafef.test.ts b/tests/cafef.test.ts
new file mode 100644
index 0000000..01d17d4
--- /dev/null
+++ b/tests/cafef.test.ts
@@ -0,0 +1,33 @@
+import { describe, it, expect } from "vitest";
+import { parseCafefDate } from "../src/data/sources/cafef.js";
+
+describe("parseCafefDate", () => {
+  it("should return undefined for empty inputs", () => {
+    expect(parseCafefDate(undefined)).toBeUndefined();
+    expect(parseCafefDate("")).toBeUndefined();
+  });
+
+  it("should parse Microsoft date format correctly", () => {
+    const timestamp = 1777512060000;
+    const input = `/Date(${timestamp})/`;
+    const expected = new Date(timestamp).toISOString();
+    expect(parseCafefDate(input)).toBe(expected);
+  });
+
+  it("should parse normal date strings and return ISO string", () => {
+    const input = "2024-05-15T10:30:00Z";
+    const expected = new Date(input).toISOString();
+    expect(parseCafefDate(input)).toBe(expected);
+  });
+
+  it("should return the original string if it is an invalid date string", () => {
+    const input = "invalid-date-string";
+    expect(parseCafefDate(input)).toBe(input);
+  });
+
+  it("should handle already ISO-ish strings correctly", () => {
+    const input = "2023-12-01";
+    const expected = new Date(input).toISOString();
+    expect(parseCafefDate(input)).toBe(expected);
+  });
+});