From 5fe919452bc9371a5deae36ff3e9bb1decd63a73 Mon Sep 17 00:00:00 2001
From: Guilherme Santos <contato.guisantos07@gmail.com>
Date: Fri, 8 Dec 2023 10:26:49 -0300
Subject: [PATCH] test: Make sure response is still writable before setting
 headers (#12478)

---
 packages/lib/server/defaultResponder.test.ts | 22 ++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 packages/lib/server/defaultResponder.test.ts

diff --git a/packages/lib/server/defaultResponder.test.ts b/packages/lib/server/defaultResponder.test.ts
new file mode 100644
index 0000000000..25276230be
--- /dev/null
+++ b/packages/lib/server/defaultResponder.test.ts
@@ -0,0 +1,22 @@
+import type { NextApiRequest, NextApiResponse } from "next";
+import { describe, it, expect, vi } from "vitest";
+
+import { defaultResponder } from "./defaultResponder";
+
+describe("defaultResponder", () => {
+  it("should call res.json when response is still writable and result is not null", async () => {
+    const f = vi.fn().mockResolvedValue({});
+    const req = {} as NextApiRequest;
+    const res = { json: vi.fn(), writableEnded: false } as unknown as NextApiResponse;
+    await defaultResponder(f)(req, res);
+    expect(res.json).toHaveBeenCalled();
+  });
+
+  it("should not call res.json when response is not writable", async () => {
+    const f = vi.fn().mockResolvedValue({});
+    const req = {} as NextApiRequest;
+    const res = { json: vi.fn(), writableEnded: true } as unknown as NextApiResponse;
+    await defaultResponder(f)(req, res);
+    expect(res.json).not.toHaveBeenCalled();
+  });
+});