redux-saga: How to create multiple calls/side-effects programmatically for yield?

Question

With redux-saga, one can execute multiple effects in parallel:

import { call } from 'redux-saga/effects'

// correct, effects will get executed in parallel
const [users, repos]  = yield [
  call(fetch, '/users'),
  call(fetch, '/repos')
]

How can i create those "call"-calls programmatically?

What i want to achieve is this:

Lets say i have an array with different parameters and i want to execute a request to a server per parameter, but in parallel with redux-saga:

const parameters = ['abc', 'def', 'ghi']

const allMyFetchCalls  = parameters.map( (p) => makeCallRequestWithParameter(p) );

makeCallRequestWithParameter would create a function call (or in redux-saga-speech: an effect) call(fetch, param) like in yield call(fetch, param)

const resultArray = yield allMyFetchCalls;

Is this possible and if so, how?

Answer 1

Please note that call effect doesn't call anything at the time. It just creates Plain JavaScript Object and returns. So what you want is not so difficult.

import { call } from 'redux-saga/effects'

const params = ['abc', 'def', 'ghi']
const responses  = yield params.map(p => call(fetch, p))