Express Testing (Jest + Supertest)

npm install --save-dev jest supertest

{
  "scripts": {
    "test": "jest --detectOpenHandles"
  },
  "jest": {
    "testEnvironment": "node",
    "testMatch": ["**/__tests__/**/*.test.js"]
  }
}

const express = require("express");
const app = express();

app.use(express.json());
app.use("/api/users", require("./routes/users"));

module.exports = app; // listen এখানে নেই!

const app = require("./app");
const connectDB = require("./config/db");

connectDB();
app.listen(process.env.PORT || 5000);

const request = require("supertest");
const app = require("../app");

describe("Users API", () => {
  test("GET /api/users → 200 ও array", async () => {
    const res = await request(app).get("/api/users");
    expect(res.statusCode).toBe(200);
    expect(Array.isArray(res.body)).toBe(true);
  });

  test("POST /api/users → validation error", async () => {
    const res = await request(app)
      .post("/api/users")
      .send({ name: "" }); // invalid

    expect(res.statusCode).toBe(400);
  });

  test("POST /api/users → 201", async () => {
    const res = await request(app)
      .post("/api/users")
      .send({ name: "রহিম", email: "r@test.com" });

    expect(res.statusCode).toBe(201);
    expect(res.body).toHaveProperty("_id");
  });
});

const { protect } = require("../middleware/auth");

describe("Auth middleware", () => {
  test("token না থাকলে 401", () => {
    const req = { headers: {} };
    const res = { status: jest.fn().mockReturnThis(), 
                  json: jest.fn() };
    const next = jest.fn();

    protect(req, res, next);

    expect(res.status).toHaveBeenCalledWith(401);
    expect(next).not.toHaveBeenCalled();
  });
});

npm test

# ✓ should pass — PASS/FAIL summary দেখাবে