How to test with the reselect createSelector function in jest?

Question

Hello I'm trying to test the createSelector function in jest but I'm stuck. So the problem is that never enters in the if of the function getContent and I need to enter, for the coverage.

File

export const selectDetailsObject = createSelector(
    [
        (state) => state.objectId,
        (state) => state.objects,
    ],
    (
        objectId,
        objects,
    ) => getContent(objectId, objects)
)

function getContent (objectId, objects) {
    const result = {}
    if (objectId && objectId !== '') {
        result.objectId = objectId
        result.objectInfo = objects[objectId]
        result.objectDetails = objectDetails[objectId]
    }
    return result
}

Testing file

const mockStore = () => ({
    objectId: '123',
    objects: {},
})

test('should select the content of the table', () => {
    const result = selectDetailsObject(mockStore)
    expect(result.objects).toBe()
})

Any suggestions?

score 2 · Accepted Answer · answered Sep 10 '19 at 15:52

selectDetailsObject needs a state object, not a function. So you can either just create a mockStore object, or call it when you hand it in:

const mockStore = () => ({
    objectId: '123',
    objects: {},
})

test('should select the content of the table', () => {
    const result = selectDetailsObject(mockStore())
    expect(result.objects).toBe()
})

How to test with the reselect createSelector function in jest?

1 Answers1