ThunkActionType prototype

Author: piotrwitek

playground/src/features/counters/thunk-actions.ts

@@ -0,0 +1,24 @@
+import { action, ActionType } from 'typesafe-actions';
+
+import { Dispatch, ActionCreatorsMapObject } from 'redux';
+import * as actions from './actions';
+
+// CLASSIC API
+export const thunkIncrement = () => (dispatch: Dispatch) =>
+  dispatch(action('THUNK_INCREMENT'));
+export const thunkAdd = (amount: number) => (dispatch: Dispatch) =>
+  dispatch(action('THUNK_ADD', amount));
+
+type ThunkActionType<M extends ActionCreatorsMapObject<any>> = ActionType<
+  {
+    [N in keyof M]: ReturnType<M[N]> extends (
+      dispatch: Dispatch
+    ) => { type: string }
+      ? (...args: Parameters<M[N]>) => ReturnType<ReturnType<M[N]>>
+      : M[N]
+  }
+>;
+
+const thunkActions = { thunkIncrement, thunkAdd, ...actions };
+export type Action = ThunkActionType<typeof thunkActions>;
+// type Action = EmptyAction<"THUNK_INCREMENT"> | PayloadAction<"THUNK_ADD", number> | EmptyAction<"counters/INCREMENT"> | PayloadAction<"counters/ADD", number>