How to simulate time delay (timeout) when mocking method calls in unit testing with proxyquire and mocha?

Question

Using proxyquire I'm mocking a method of module B (injected with require() in module A), when testing the method in the module A. The mock (mocking get_campaigns method of admitad.model.js module):

const admitadModelMock = {
    '../services/admitad.model': {
        get_campaigns: (limit, page) => new Promise((resolve, reject) =>
            setTimeout(resolve({campaigns: testData, count: 1000}), 5000)
        ),
    },
};

The test:

it('shold get all campaigns from Admitad', async function () {
    this.timeout(60000);
    let err, data;
    // mock dependencie (get_campaigns() of module B will be mocked):
    let $serviceStubbed = proxyquire('../services/campaign-sync', admitadModelMock);
    // getAdmitadCampaigns() just calls get_campaigns method of module B
    [err, data] = await to($serviceStubbed.getAdmitadCampaigns(50));
    data.length.should.be.equal(50);
});

The problem is the test passing without expected delay of 5 seconds.

Update.

This is working:

setTimeout(() => resolve({campaigns: mockedCampaigns, count: 1000}), 2000)

Here is my final nice approach:

// helper to wrap timeout generation
const timer = (data, time) =>
    new Promise((resolve, reject) =>
        setTimeout(() => resolve(data), time)
    );

// Factory function to generate mock with data we need
const blacklistedModelMockFactory =
    (onRead = [], onUpdate = 'Ok', onCreate = 'Ok', onDelete = 'Ok') => ({
        '../services/campaigns-blacklist.model': {
            read: () => timer(onRead, 2000),
            update: () => timer(onUpdate, 2000),
            create: () => timer(onCreate, 1000),
            delete: () => timer(onDelete, 1000),
        },
    });

// Test example
it('should filter Registered and Blacklisted collections', async function () {
    this.timeout(60000);
    $service.should.have.property('filterRB').a('function');
    const sourceRegistered = mockedCampaigns.slice(5, 10);
    const sourceBlacklisted = mockedCampaigns.slice(15, 18);
    let error, success;
    // mock dependencies in tested module with our expected data:
    let $serviceStubbed = proxyquire(
        '../services/campaign-sync', Object.assign(
            {},
            blacklistedModelMockFactory(sourceBlacklisted),
            registeredModelMockFactory(sourceRegistered)
        )
    );
    [error, success] = await to($serviceStubbed.filterRB(mockedCampaigns));
    expect(error).to.be.equal(null);
    success.filtered.length.should.be.equal(12);
    success.blacklisted.length.should.be.equal(3);
    success.registered.length.should.be.equal(5);
});

Answer 1

setTimeout(resolve({campaigns: testData, count: 1000}), 5000)

The above line call flow can be explained as below.

let res = resolve({campaigns: testData, count: 1000});
setTimeout(res, 5000);

You don't want that, do you :-)

Try,

setTimeout(() => resolve({ campaigns: testData, count: 1000 }), 5000)

as it wraps the resolve call inside an anonymous function and passes that as 1st parameter to setTimeout call.