timeout async callback testing with sinon jest supertest to simulate error 500 on express api - express

Question

I am testing an api with all http 500 errors.
Here I try to use sinon.stub to test on a failing server and get a 500 error, but I get a timeOut async callback, or if I use my app a successfull 200 response statusCode as if sinon.stub has no effect. I must miss something and I am stucked...
would you see a horrifying error below ?
thanks for your precious help
process.env.NODE_ENV = "test";
const app = require("../../app");
const request = require("supertest");
const sinon = require("sinon");
// /************************** */
const usersRoute = require("../../routes/Users");
const express = require("express");
const initUsers = () => {
const app = express();
app.use(usersRoute);
return app;
};
describe("all 5xx errors tested with stub", function () {
it("should return a 500 when an error is encountered", async (done) => {
let secondApp;
sinon.stub(usersRoute, "post").throws(
new Error({
response: { status: 500, data: { message: "failed" } },
})
);
secondApp = initUsers(); //==========> Timeout Async Callback
//secondApp = require("../../app"); //==============> gives a 200 instead of 500
const fiveHundredError = await request(secondApp)
.post("/users/oauth?grant_type=client_credentials")
.send({
username: "digitalAccount",
password: "clientSecret",
});
expect(fiveHundredError.statusCode).toBe(500);
//sinon.restore();
done();
});
});
app is using express.Router to get users route :
const express = require("express");
const router = express.Router();
const axios = require("axios");
router.post("/users/oauth", async (req, res) => {
//if (all missing parts)
//else {
try {
if (req.fields) {
const response = await axios.post(
`${base_url}oauth/token?grant_type=${req.query.grant_type}`,
{},
{
auth: {
username: req.fields.username,
password: req.fields.password,
},
}
);
res.json(response.data);
}
} catch (error) {
return res.status(error.response.status).json(error.response.data);
}
}
});
module.exports = router;
See server.js :
const app = require("./app");
const port = process.env.PORT || 5000;
app.listen(port, () => console.log(`server starting on port ${port}!`));
and app.js :
// private environment:
require("dotenv").config();
const express = require("express");
const formidableMiddleware = require("express-formidable");
const cors = require("cors");
const app = express();
app.use(formidableMiddleware());
app.use(cors());
const usersRoute = require("./routes/Users");
app.use(usersRoute);
app.get("/", (req, res) => {
res.status(200).send("Welcome to Spark Admin back end!");
});
app.all("*", (req, res) => {
return res.status(404).json({ error: "Web url not found" });
});
module.exports = app;

Answer 1

I finally opted for 'nock' and deleted 'sinon'
const nock = require("nock");
const axios = require("axios");
describe("POST login: all 5xx errors tested with nock", function () {
it("should return a 500 when an error is encountered", async (done) => {
const scope = nock("http://localhost:5000")
.post(
"/users/oauth",
{},
{
username: "blibli",
password: "blabla",
}
)
.reply(500, {
response: {
statusCode: 500,
body: { error: "AN ERROR OCCURED" },
},
});
try {
await axios.post(
"http://localhost:5000/users/oauth",
{},
{
username: "blibli",
password: "blabla",
}
);
} catch (e) {
expect(e.response.status).toBe(500);
}
done();
});
});