index.spec.ts

import useCombine from './index';
import { vi, assert, expect, test,  expectTypeOf } from 'vitest'


const userInitialState = { name: 'name' };
const todosInitialState = { todos: [1, 2, 3] };

test('should merge states with provided keys', () => {
  const [state] = useCombine({
    user: [userInitialState, (state) => state],
    todos: [todosInitialState, (state) => state],
  });

  assert.deepEqual(state, {
    user: userInitialState,
    todos: todosInitialState,
  });
});

test('should infer state type', () => {
  const [state] = useCombine({
    user: [userInitialState, (state) => state],
    todos: [todosInitialState, (state) => state],
  });

  expectTypeOf(state).toEqualTypeOf<{
    user: {name: string}
    todos: {todos: number[]}
  }>()
})

test('should call all passed reducers', () => {
  const reducerA = vi.fn();
  const reducerB = vi.fn();
  const action = { type: 'init' };

  const [_, dispatch] = useCombine({
    user: [userInitialState, reducerA],
    todos: [todosInitialState, reducerB],
  });

  dispatch(action);

  expect(reducerA).toHaveBeenCalledTimes(1);
  expect(reducerA).toHaveBeenCalledWith(action);
  expect(reducerB).toHaveBeenCalledTimes(1);
  expect(reducerB).toHaveBeenCalledWith(action);
});