Add test for defaeult handler (#15258)

Author: sean-brydon

packages/lib/server/defaultHandler.test.ts

@@ -0,0 +1,61 @@
+import { createMocks } from "node-mocks-http";
+import { describe, it, expect, vi, afterEach } from "vitest";
+
+import { defaultHandler } from "./defaultHandler";
+
+describe("defaultHandler Test Suite", () => {
+  afterEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("should return 405 for unsupported HTTP methods", async () => {
+    const handlers = {};
+    const handler = defaultHandler(handlers);
+
+    const { req, res } = createMocks({
+      method: "PATCH", // Unsupported method here
+    });
+
+    await handler(req, res);
+
+    expect(res._getStatusCode()).toBe(405);
+    expect(res._getJSONData()).toEqual({
+      message: "Method Not Allowed (Allow: )",
+    });
+  });
+
+  it("should call the correct handler for a supported method", async () => {
+    const getHandler = vi.fn().mockResolvedValue(null);
+    const handlers = {
+      GET: { default: getHandler },
+    };
+    const handler = defaultHandler(handlers);
+
+    const { req, res } = createMocks({
+      method: "GET",
+    });
+
+    await handler(req, res);
+
+    expect(getHandler).toHaveBeenCalledWith(req, res);
+  });
+
+  it("should return 500 for errors thrown in handler", async () => {
+    const getHandler = vi.fn().mockRejectedValue(new Error("Test Error"));
+    const handlers = {
+      GET: { default: getHandler },
+    };
+    const handler = defaultHandler(handlers);
+
+    const { req, res } = createMocks({
+      method: "GET",
+    });
+
+    await handler(req, res);
+
+    expect(res._getStatusCode()).toBe(500);
+    expect(res._getJSONData()).toEqual({
+      message: "Something went wrong",
+    });
+  });
+});