diff --git a/tests/unit/platforms/curseforge/curseforge-project.spec.ts b/tests/unit/platforms/curseforge/curseforge-project.spec.ts
new file mode 100644
index 0000000..7db72dd
--- /dev/null
+++ b/tests/unit/platforms/curseforge/curseforge-project.spec.ts
@@ -0,0 +1,31 @@
+import { isCurseForgeProjectId } from "@/platforms/curseforge/curseforge-project";
+
+describe("isCurseForgeProjectId", () => {
+    test("returns true when input is a number", () => {
+        expect(isCurseForgeProjectId(123456)).toBe(true);
+    });
+
+    test("returns true when input is a string containing an integer", () => {
+        expect(isCurseForgeProjectId("123456")).toBe(true);
+    });
+
+    test("returns false when input is a string containing non-integer characters", () => {
+        expect(isCurseForgeProjectId("123abc")).toBe(false);
+    });
+
+    test("returns false when input is a string containing floating point number", () => {
+        expect(isCurseForgeProjectId("123.456")).toBe(false);
+    });
+
+    test("returns false when input is an empty string", () => {
+        expect(isCurseForgeProjectId("")).toBe(false);
+    });
+
+    test("returns false when input is null", () => {
+        expect(isCurseForgeProjectId(null)).toBe(false);
+    });
+
+    test("returns false when input is undefined", () => {
+        expect(isCurseForgeProjectId(undefined)).toBe(false);
+    });
+});