Jest how to test express API POST request? - node.js

Question

I need to test if my POST request to my endpoint works properly with a Jest test. I had the idea of first getting the count of my Services table (I'm using sequelize orm), then to send a new post request and to finally get the new count and compare if the old count + 1 will equal to the new count, if true then the POST request works just fine.
test('Create a valid Service', async (done) => {
const service = {
name: "cool",
description: "description"
};
await Service.count().then(async function (count) {
await request(app)
.post('/api/services')
.send(service)
.then(async () => {
await Service.count().then(function (newcount) {
expect(newcount).toBe(count + 1);
});
})
.catch(err => console.log(`Error ${err}`));
});
});
For me the test looks fine, but when I run it I get:
Timeout - Async callback was not invoked within the 5000ms timeout specified by jest.setTimeout.
Is something missing or is there even a better way to test a POST request? with Jest?

Answer 1

It is because you are not calling the done callback passed in jest callback function. It can be done like this.
test('Create a valid Service', async(done) => {
const service = {
name: "cool",
description: "description"
};
await Service.count().then(async function (count) {
await request(app)
.post('/api/services')
.send(service)
.then(async() => {
await Service.count().then(function (newcount) {
expect(newcount).toBe(count + 1);
// execute done callback here
done();
});
})
.catch(err => {
// write test for failure here
console.log(`Error ${err}`)
done()
});
});
});
You can also write this code in this way so that the readability can be improved and maximize the use of async/await.
test('Create a valid Service', async(done) => {
const service = {
name: "cool",
description: "description"
};
try {
const count = await Service.count();
await request(app).post('/api/services').send(service)
const newCount = await Service.count()
expect(newCount).toBe(count + 1);
done()
} catch (err) {
// write test for failure here
console.log(`Error ${err}`)
done()
}
});
By default Jest also resolves the promise in async/await case. We can achieve this without the callback function also
test('Create a valid Service', async() => {
const service = {
name: "cool",
description: "description"
};
try {
const count = await Service.count();
await request(app).post('/api/services').send(service)
const newCount = await Service.count()
expect(newCount).toBe(count + 1);
} catch (err) {
// write test for failure here
console.log(`Error ${err}`)
}
});