undefined is not an object (evaluating '_effects.buffers.expanding') - react-native

Question

I'm getting an error when tried to copy&paste this solution in my app.
undefined is not an object (evaluating 'effects.buffers.expanding')
My code is pretty similar:
export function* handleBleState() {
const {
bleConnections: { manager },
} = yield select()
const stateChannel = yield eventChannel((emit) => {
const subscription = manager.onStateChange((state) => {
emit(state)
}, true)
return () => {
subscription.remove()
}
}, buffers.expanding(1))
try {
for (;;) {
const newState = yield take(stateChannel)
const power = newState === 'PoweredOn'
yield put(BLEActions.updateBleState(power))
}
} finally {
if (yield cancelled()) {
stateChannel.close()
}
}
}
But what is more strange is that I have extracted code from the documentation of redux-saga and the error is similar.
I replaced part of the code with this:
const stateChannel = yield eventChannel((emitter) => {
const iv = setInterval(() => {
secs -= 1
if (secs > 0) {
emitter(secs)
} else {
// this causes the channel to close
emitter(END)
}
}, 1000)
// The subscriber must return an unsubscribe function
return () => {
clearInterval(iv)
}
})
And I get:
undefined is not a function (evaluating '(0, _effects.eventChannel)')
I'm using another version of redux-saga:
"redux-saga": "^1.0.2",
But I tried with the same version that he use
"redux-saga": "0.16.2"
And then the issue is another one:
console.error: "unchaught at root", "at root at takeLatest" at handleBleState etc, etc.
Any help will be welcome, thanks in advance.
PD:
"react": "16.6.1",
"react-native": "0.57.5",
"react-native-ble-plx": "^1.0.1",

Answer 1

the eventChannel is nor part of the effects but defined directly in the main module, see the relevant API doc. So if you're using ES6 import/export you import it with the following statement:
import { eventChannel } from 'redux-saga'
While the require equivalent should be:
const eventChannel = require('redux-saga').eventChannel