Saga Helpers

Redux Saga Test Plan also offers assertions for the saga helper effects takeEvery, takeLatest, and throttle. These helpers come in two flavors. Your sagas can delegate (i.e. use yield*) to these helpers if you import them directly from the redux-saga module. This is now a deprecated pattern according to Redux Saga. You are encouraged to now import the equivalent effect creators for these helpers from the redux-saga/effects module and just yield them like other effect creators. Redux Saga still supports delegating to the helpers, but if it removes support for delegation, then Redux Saga Test Plan will also necessarily remove support for testing delegations.

To decide which assertions you need for testing your saga, please review the possibilities below:

1. If you are using the helper effect creators from redux-saga/effects, you can use the respective methods takeEveryEffect, takeLatestEffect, and throttleEffect from Redux Saga Test Plan.

2. If your saga delegates to any of these helpers from redux-saga directly, then you can use the respective takeEvery, takeLatest, and throttle methods from Redux Saga Test Plan. The difference between these assertions and the normal effect creator assertions is that you shouldn't call next on your test saga beforehand. These methods will automatically advance the saga for you.

   DEPRECATION NOTICE:
   Delegating is now a deprecated pattern for Redux Saga. Please move to using the effect creators added in Redux Saga v0.14.0. If Redux Saga removes this pattern, then Redux Saga Test Plan will also remove the respective assertion methods.

3. Starting in Redux Saga v0.12.0, instead of delegating to the helpers from the redux-saga module, you could instead yield them like normal effect creators such as call or put. These are non-blocking yields; internally, Redux Saga will fork them like the normal fork effect creator. If you yield instead of delegating, then you can use the respective takeEveryFork, takeLatestFork, and throttleFork methods from Redux Saga Test Plan. Because these assertions are like the normal effect creator assertions, you WILL need to call next prior to these assertions.

   DEPRECATION NOTICE:
   Because these are the same helpers you can delegate to, this pattern may also be removed by Redux Saga, meaning Redux Saga Test Plan will also remove the respective assertion methods.

Summary

Delegating Example

import { takeEvery } from 'redux-saga';
import { call } from 'redux-saga/effects';
import testSaga from 'redux-saga-test-plan';

function identity(value) {
  return value;
}

function* otherSaga(action, value) {
  yield call(identity, value);
}

function* anotherSaga(action) {
  yield call(identity, action.payload);
}

function* mainSaga() {
  yield call(identity, 'foo');
  yield* takeEvery('READY', otherSaga, 42);
}

// All good
testSaga(mainSaga)
  .next()
  .call(identity, 'foo')
  .takeEvery('READY', otherSaga, 42)
  .finish()
  .isDone();

// Will throw
testSaga(mainSaga)
  .next()
  .call(identity, 'foo')
  .takeEvery('READY', anotherSaga, 42)
  .finish()
  .isDone();

// SagaTestError:
// Assertion 2 failed: expected takeEvery to fork anotherSaga
//
// Expected
// --------
// [Function: anotherSaga]
//
// Actual
// ------
// [Function: otherSaga]

Yielding Example

import { takeEvery } from 'redux-saga';
import { call } from 'redux-saga/effects';
import testSaga from 'redux-saga-test-plan';

function identity(value) {
  return value;
}

function* otherSaga(action, value) {
  yield call(identity, value);
}

function* anotherSaga(action) {
  yield call(identity, action.payload);
}

function* mainSaga() {
  yield call(identity, 'foo');
  yield takeEvery('READY', otherSaga, 42);
}

// All good
testSaga(mainSaga)
  .next()
  .call(identity, 'foo')

  .next()
  .takeEveryFork('READY', otherSaga, 42)

  .finish()
  .isDone();

// Will throw
testSaga(mainSaga)
  .next()
  .call(identity, 'foo')

  .next()
  .takeEveryFork('READY', anotherSaga, 42)

  .finish()
  .isDone();

// SagaTestError:
// Assertion 2 failed: expected takeEvery to fork anotherSaga
//
// Expected
// --------
// [Function: anotherSaga]
//
// Actual
// ------
// [Function: otherSaga]