Recoil指南--Testing 测试

Testing Recoil Selectors outside of React React之外测试Recoil的Selectors

It can be useful to manipulate and evaluate Recoil selectors outside of a React context for testing. This can be done by working with a Recoil Snapshot. You can build a fresh snapshot using snapshot_UNSTABLE() and then use that Snapshot to evaluate selectors for testing.
脱离React来测试Recoil的Selectors是非常有用的。这可以通过Recolid的Snapshot来实现。可以通过snapshot_UNSTABLE()函数来创建一个全新的snapshot，然后用Snapshot来实现selector的测试。

Example: Jest unit testing selectors Selectors的单元测试

const numberState = atom({key: 'Number', default: 0});

const multipliedState = selector({
    key: 'MultipliedNumber',
    get: ({get}) => get(numberState) * 100,
});

test('Test multipliedState', () => {
    const initialSnapshot = snapshot_UNSTABLE();
    expect(mySnapshot.getLoadable(multipliedState).valueOrThrow()).toBe(0);

    const testSnapshot = snapshot_UNSTABLE(({set}) => set(numberState, 1));
    expect(mySnapshot.getLoadable(multipliedState).valueOrThrow()).toBe(100);
})