Javascript 调用另一个异步函数的异步函数的Jest测试失败
我正在尝试测试一个异步函数,该函数使用另一个异步函数返回的数据。下面是解释我的问题的代码:Javascript 调用另一个异步函数的异步函数的Jest测试失败,javascript,unit-testing,jestjs,enzyme,Javascript,Unit Testing,Jestjs,Enzyme,我正在尝试测试一个异步函数,该函数使用另一个异步函数返回的数据。下面是解释我的问题的代码: StudentInfo.js export async function getData() { //studentData imported from another file return new Promise(resolve => { setTimeout(() => { resolve(studentData); }, 5000); }); }
StudentInfo.js
export async function getData() {
//studentData imported from another file
return new Promise(resolve => {
setTimeout(() => {
resolve(studentData);
}, 5000);
});
}
export async function filterStudents() {
const studentData = await StudentInfo.getData();
//computations
return filteredData; //object
}
StudentInfo.test.js
import * as studentInfo from "src/StudentInfo.js"
describe("StudentInfo" , () => {
test("student data correctly filtered", async () => {
const studentData = [
{
name: Sarah Marshall,
id: srhmar451
},
{...}
];
expectedData = { [...], [...]};
const spy = jest.spyOn(studentInfo, "getData");
spy.mockReturnValue(studentData);
await expect(studentInfo.filterStudents()).toEqual(expectedData);
});
});
我的测试失败,因为预期的返回值是
Promise{}
。有人能帮我为我的filterStudents()
函数写一个测试吗?我在这方面已经坚持太久了。以下是一个可以帮助您开始的工作示例:
StudentInfo.js
import * as StudentInfo from './StudentInfo';
export async function getData() {
throw new Error('should not get here'); // <= getData will be mocked
}
export async function filterStudents() {
const studentData = await StudentInfo.getData();
return studentData.filter(v => v.id === '2');
}
您可以使用将返回值模拟为解析为传递给它的值的
Promise
(尽管如果您只是使用,也可以正常工作,因为对值调用await
是有效的,例如const five=await 5;//因为您在监视异步函数,所以应该使用spy.mockResolvedValue(学生数据)
import * as StudentInfo from "./StudentInfo"
describe("StudentInfo", () => {
test("student data correctly filtered", async () => {
const studentData = [
{ name: 'student1', id: '1' },
{ name: 'student2', id: '2' },
{ name: 'student3', id: '3' }
];
jest.spyOn(StudentInfo, "getData").mockResolvedValue(studentData);
await expect(StudentInfo.filterStudents()).resolves.toEqual([{ name: 'student2', id: '2' }]); // Success!
});
});