redux_types.js

import type { GlobalState } from 'redux/modules';

export type ExtractReturn<Fn> = $Call<<T>((...Iterable<any>) => T) => T, Fn>;

// ...

export type BaseAction = $ReadOnly<{ type: string, error?: boolean }>;

// ...

export type GetState<S> = () => S;
export type GetGlobalState = GetState<GlobalState>;
export type PromiseAction<A: BaseAction> = Promise<A>;
export type ThunkAction<A, S = GlobalState> = (dispatch: Dispatch<A>, getState: GetState<S>) => any;

export type Dispatch<A: BaseAction, S = GlobalState> = (
  action: A | ThunkAction<A, S> | PromiseAction<A> | Array<A>
) => Promise<*>;

// ...

export type DispatchLoose<A> = (
  action: A | ThunkAction<A> | PromiseAction<A> | Array<A>
) => Promise<any>;

// ...

export type ExtractReturnWithDispatch = <V>((...args: Array<*>) => V) => DispatchLoose<V>;

export type ReduxProps<M, D> = $ReadOnly<{| ...ExtractReturn<M>, ...ExtractReturn<D> |}>;

export type ReduxPropsWithDispatchShorthand<M, D> = $ReadOnly<{|
  ...ExtractReturn<M>,
  ...$ObjMap<D, ExtractReturnWithDispatch>,
|}>;