MyCrypto/shared/types/sagaHelpers.d.ts

23 lines
1.0 KiB
TypeScript

import { Effect } from 'redux-saga/effects';
type ExtPromise<T> = T extends Promise<infer U> ? U : T;
type ExtSaga<T> = T extends IterableIterator<infer U> ? Exclude<U, Effect | Effect[]> : T;
/**
* Use this helper to unwrap return types from effects like Call / Apply
* In the case of calling a function that returns a promise, this helper will unwrap the
* promise and return the type inside it. In the case of calling another saga / generator,
* this helper will return the actual return value of the saga / generator, otherwise,
* it'll return the original type.
*
* NOTE 1: When using this to extract the type of a Saga, make sure to remove the `SagaIterator`
* return type of the saga if it contains one, since that masks the actual return type of the saga.
*
* NOTE 2: You will most likely need to use the `typeof` operator to use this helper.
* E.g type X = UnwrapEffects<typeof MyFunc/MySaga>
*/
export type UnwrapEffects<T> = T extends (...args: any[]) => any
? ExtSaga<ReturnType<T>>
: ExtPromise<T>;