unit-testing - typescript 中的Sinon stub 私有(private)变量？

Question

我想在一个类中 stub 一个私有(private)变量

class IPC {
    private publisher: redis.RedisClient;
    constructor() {
        this.publisher = redis.createClient();
    }

    publish(text: string) {
        const msg = {
            text: text
        };

        this.publisher.publish('hello', JSON.stringify(msg));
    }
}

如何 stub 私有(private)变量 publisher ，在这个类里面？
所以我可以测试如下所示的代码

it('should return text object', () => {
    const ipc = sinon.createStubInstance(IPC);
    ipc.publish('world!');

    // this will throw error, because ipc.publisher is undefined
    assert.deepStrictEqual({
        text: 'world!'
    }, ipc.publisher.getCall(0).args[0]) 
})

Answer 1

您可以使用类型断言来访问私有(private)变量。像:

(ipc as any).publisher