Using redux-saga-test-plan, I have a dispatch action that takes a function as an argument. This makes the test always fail

Question

I have a saga that yields a put. One of the arguments to that put is a function object.

I've copied the saga function only as far as it is relevant:

function* updateTaskTimeCancelledTimeRejectedSuccess(action) {
    const {payload} = action.data
    const tasks = yield select(getTasksSelector);
    const parent = yield call(findExistingTaskParent, tasks, action.data.taskUUID);
    if (action.type === taskActions.updateTaskCancelledTimeActions.success) {
        const currentValue = parent.taskGroup[action.data.taskUUID].time_cancelled;
        if (currentValue === null) {
            // only notify if marking rejected for the first time
            const restoreActions = yield () => [taskActions.updateTaskCancelledTimeRequest(
                action.data.taskUUID,
                {time_cancelled: null}
            )];
            const viewLink = `/task/${encodeUUID(action.data.taskUUID)}`
            yield put(displayInfoNotification("Task marked cancelled", restoreActions, viewLink))

This is the test:

   it("updates the task state with cancelled time and sends a notification", () => {
        const action = {type: taskActions.updateTaskCancelledTimeActions.success, data: {taskUUID: "someUUID", time_cancelled: new Date().toISOString()}};
        const restoreActions = () => [taskActions.updateTaskCancelledTimeRequest(
            action.data.taskUUID,
            {time_cancelled: null}
        )];
        const viewLink = `/task/${encodeUUID(action.data.taskUUID)}`
        return expectSaga(testable.updateTaskTimeCancelledTimeRejectedSuccess, action)
            .provide([
                [select(getTasksSelector), {
                    tasksNew: {
                        1: {
                            someUUID: {
                                time_cancelled: null,
                                parent_id: 1
                            }
                        }
                    }
                }]])
            .put(displayInfoNotification("Task marked cancelled", restoreActions, viewLink))
            .run()


    })
})

and this is the result:

    SagaTestError:
    put expectation unmet:

    Expected
    --------
    { '@@redux-saga/IO': true,
      combinator: false,
      type: 'PUT',
      payload:
       { channel: undefined,
         action:
          { type: 'DISPLAY_INFO_NOTIFICATION',
            message: 'Task marked cancelled',
            restoreActions: [Function: restoreActions],
            viewLink: '/task/0000000000000000000000' } } }

    Actual:
    ------
    1. { '@@redux-saga/IO': true,
      combinator: false,
      type: 'PUT',
      payload:
       { channel: undefined,
         action:
          { type: 'DISPLAY_INFO_NOTIFICATION',
            message: 'Task marked cancelled',
            restoreActions: [Function],
            viewLink: '/task/0000000000000000000000' } } }

      at node_modules/redux-saga-test-plan/lib/expectSaga/expectations.js:48:13
      at node_modules/redux-saga-test-plan/lib/expectSaga/index.js:544:7
          at Array.forEach (<anonymous>)
      at checkExpectations (node_modules/redux-saga-test-plan/lib/expectSaga/index.js:543:18)

It's obvious to me that the equality is failing because of the restoreActions object which is a function of a different reference. I can't figure out what I should do instead to make the test pass. What do I need to do to verify the saga is flowing as I expected? I don't necessarily need to verify the result of the function, just that the displayInfoNotification put took place.

Thank you.

Answer 1

Make a factory function for your restoreActions lambda and then you can mock it for your test.

e.g.

// somewhere in your module
const actionRestoreFactory = (action) => () => [taskActions.updateTaskCancelledTimeRequest(action.data.taskUUID, {time_cancelled: null})]

//In your saga
yield put(displayInfoNotification("Task marked cancelled", actionRestoreFactory(action), viewLink))

//In your test
import actionRestoreFactory from './your/module'
jest.mock('./your/module')
actionRestoreFactory.mockReturnValue(jest.fn())
//...
return expectSaga(testable.updateTaskTimeCancelledTimeRejectedSuccess, action)
         .provide([ ... ])
         .put(displayInfoNotification("Task marked cancelled", actionRestoreFactory(action), viewLink))
         .run()