writing jest test cases for util classes - vuejs2

Question

in Vue , I have a util class where i abstracted the axios invocation and bit of logic..
import Axios from 'axios'..the code almost looks like this
export default {
getStudentNumber (name) {
Axios.post('myurl', { studentName: name }).then({
//some logic
//return
})
}
}
This is being invoked from my Vue class... I wrote jest test cases for Vue and I mocked the Axios in that...But is there a way to write separate test cases for this service class ? How to write it? Becuase I have a lot of logic in this... I am using jest

Answer 1

You can write the test for your service like this:
import Axios from 'axios';
import myService from './myService';
jest.mock('axios');
describe('my service', () => {
describe('getStudentNumber', () => {
it('should call Axios.post with myurl and studentName', () => {
myService.getStudentNumber('mock name');
expect(Axios.post).toHaveBeenCalledWith('myurl', { studentName: 'mock name' })
});
describe('given a successful response', () => {
beforeAll(() => {
// setup mock for successful flow
Axios.post.mockResolvedValue({ responseMock });
});
it('should do this', () => {
const result = myService.getStudentNumber();
// describe the expected result
expect(result).toEqual({ ...... });
});
});
describe('given an error', () => {
beforeAll(() => {
// setup mock for non-successful flow
Axios.post.mockRejectedValue(new Error('some mock error'));
});
it('should do that', () => {
const result = myService.getStudentNumber();
// describe the expected result
expect(result).toEqual({ ...... });
});
});
});
});