Returning a Promise from "describe" is not supported. Tests must be defined synchronously

user_376702 0
Viewed 19511

Particular test passed but I am getting this. 

    console.log node_modules/jest-jasmine2/build/jasmine/Env.js:502
          ● 

Test suite failed to run

            Returning a Promise from "describe" is not supported. Tests must be defined synchronously.
            Returning a value from "describe" will fail the test in a future version of Jest.

        > 4 | describe('handlers.getSemesters', async () => {

Here is complete test code

describe('handlers.getSemesters', async () => {
      it('should return an array of Semesters', async () => {
        academicCalendarRequest.request = jest.fn();
        academicCalendarRequest.request.mockReturnValue([
          {
            description: 'Semester1',
          }
        ]);
        const expected = [      
          {
            description: 'Semester1',
          },
        ];

        const handlers = new Handlers();
        const actual = await handlers.getSemesters();
        expect(actual).toEqual(expected);
      });
    });

How can I fix it?

jestjs node.js javascript
2 Answers

Change

describe('handlers.getSemesters', async () => {

To

describe('handlers.getSemesters', () => {

And then put asynchronous code inside of it block

it('should return an array of Semesters', async () => {
  // ...
})
user_5379980

In my case I needed to get async result for working within multiple tests. "Describe" has to be sync and we can't use nested test blocks:

describe('Not valid nested structure', () => {
    it('async parent', async () => {
        it('child', () => {})
    });
});

So my solution is:

    describe('TaskService', () => {
        let testTask;
        
        // Common async test
        it('should set test task', async () => {
            testTask = await connection.create();
            // you can add expect here
        });

        it('should update task', async () => {
            testTask.status = null;
            const updated = await connection.update(testTask);

            expect(updated.status).toEqual(null);
        });

        it('other operation with testTask above', async () => {
            // ..
        });
    });
user_84102900
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