import downloadFile from '../downloadFile'
jest
  .useFakeTimers()
  .setSystemTime(new Date('2020-01-01').getTime());

  global.URL.createObjectURL = jest.fn();
(window as any).global.Blob = function (content, options){return  ({content, options})}

describe('downloadFile', () => {
    it('Creates an <a> tag', () => {
        const createElementSpy = jest.spyOn(document, 'createElement');
        downloadFile('hi', 'filename')
        expect(createElementSpy).toBeCalled()
    })
    it('Creates the blob with the correct data', () => {
        const data = 'writingtestsishard'
        global.URL.createObjectURL = jest.fn(() => data);
        downloadFile(data, 'filename')
        const expected = {
            content: [data],
            options: {
                type: "text"
            }
        }
        expect(global.URL.createObjectURL).toBeCalledWith(expected)
    })
})