Loose match one value in jest.toHaveBeenCalledWith

Question

I have an analytics tracker that will only call after 1 second and with an object where the intervalInMilliseconds (duration) value is not deterministic.

How can I use jest.toHaveBeenCalledWith to test the object?

 test('pageStats - publicationPage (will wait 1000ms)', done => {   const track = jest.fn()    const expected = new PayloadTiming({     category: 'PublicationPage',     action: 'PublicationPage',     name: 'n/a',     label: '7',     intervalInMilliseconds: 1000 // or around   })    mockInstance.viewState.layoutMode = PSPDFKit.LayoutMode.SINGLE   const sendPageStats = pageStats({     instance: mockInstance,     track,     remoteId: nappConfig.remoteId   })    mockInstance.addEventListener('viewState.currentPageIndex.change', sendPageStats)    setTimeout(() => {     mockInstance.fire('viewState.currentPageIndex.change', 2)      expect(track).toHaveBeenCalled()     expect(track).toHaveBeenCalledWith(expected)      done()   }, 1000)    expect(track).not.toHaveBeenCalled() }) 

expect(track).toHaveBeenCalledWith(expected) fails with:

Expected mock function to have been called with:       {"action": "PublicationPage", "category": "PublicationPage", "intervalInMilliseconds": 1000, "label": "7", "name": "n/a"}     as argument 1, but it was called with       {"action": "PublicationPage", "category": "PublicationPage", "intervalInMilliseconds": 1001, "label": "7", "name": "n/a"} 

I have looked at jest-extended but I do not see anything useful for my use-case.

Answer 1

This can be done with asymmetric matchers (introduced in Jest 18)

expect(track).toHaveBeenCalledWith(   expect.objectContaining({    "action": "PublicationPage",     "category": "PublicationPage",     "label": "7",    "name": "n/a"   }) ) 

If you use jest-extended you can do something like

expect(track).toHaveBeenCalledWith(   expect.objectContaining({    "action": "PublicationPage",     "category": "PublicationPage",     "label": "7",    "name": "n/a",    "intervalInMilliseconds": expect.toBeWithin(999, 1002)   }) )