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@yelouafi yelouafi released this 02 Oct 13:46


  • Added new effect flush (API docs). It can be used to clear buffered items in the channel and geting them back in a batch in the saga (thanks to @Andarist)

  • Added a new helper throttle (API docs)(thanks to @Andarist)

  • Added a new buffer type expanding (API docs) (thanks to @Andarist) . This new type also fixes the breaking change that was introduced by v0.11.1 with the new internal buffer implementation (see #511 [only if you need more details]).

    TL/DR: Use buffer.fixed(limit) when you need a bounded buffer (will throw an error when the untaked messages exceed the buffer limit). Use buffer.expanding(limit) when you need an auto expanding buffer.

  • createSagaMiddleware supports a new (optional) option: onError API docs to detect uncaught exceptions from Sagas (thanks to @secobarbital)

  • Saga helpers (takeEvery, takeLatest, throttle) are now non blocking (thanks to @Andarist).

Saga helpers return Iterator objects. In previous versions they were treated just like other Iterators and Promises in redux-saga, the Saga calling a helper (either via yield or yield*) will block until the Iterator returns. But since Saga helpers never return (because they are looping forever ) this will also cause the calling Saga to block forever. So in previous versions, if you wanted to call a helper in a non blocking way you had to use the fork effect

function* saga1() { ... }

function* saga2() { ... }

function* mainSaga() {
  yield fork(takeEvery, 'ACTION_1', saga1)
  yield fork(takeLatest, 'ACTION_2', saga2)

With this change, redux-saga handles the helpers like forks when used with yield which mean you can call them directly like this

function* mainSaga() {
  const task1 = yield takeEvery('ACTION_1', saga1)
  const task2 = yield takeLatest('ACTION_2', saga2)

Note this will not work when used with the delegation form yield*: eg yield* takeEvery(...) will block the Generator. This is due to how yield* works in Generators in JavaScript and can't be handled by redux-saga.