Question

我需要测试一系列异步函数是按特定顺序调用的。有一个简单的方法吗？

我想在下面实现的一个例子：

describe("Test ASYNC order", () => {
    it("Calls in a particular order", () => {
        const p1 = new Promise(resolve => setTimeout(resolve, 500));
        const p2 = new Promise(resolve => setTimeout(resolve, 600));
        const p3 = new Promise(resolve => setTimeout(resolve, 200));

        /* How would I test that the order of the promises resolving is p3 then p1 then p2 ????? */
    })
})

Answer 1

一种方法是：

test('Calls in a particular order', async () => {
    const res = [];
    const storeRes = index => res.push(index);
    const p1 = new Promise(resolve => setTimeout(resolve, 500)).then(() => storeRes(1));
    const p2 = new Promise(resolve => setTimeout(resolve, 600)).then(() => storeRes(2));
    const p3 = new Promise(resolve => setTimeout(resolve, 200)).then(() => storeRes(3));
    await Promise.all([p1, p2, p3]);
    expect(res).toEqual([3, 1, 2]);
});

它在每个promise之后将值推送到数组，并且一旦所有这些都已解析，就会根据预期的顺序测试result数组中值的顺序。

如何使用Jest测试ASYNC请求的顺序

1 个答案: