function binaryParser(res, callback) {
 res.setEncoding('binary')
 res.data = ''
 res.on('data', function (chunk) {
 res.data += chunk
 })
 res.on('end', function () {
 callback(null, new Buffer(res.data, 'binary'))
 })
 }
 describe('exports/:id (GET)', () => {
 it('should return an excel File', async () => {
 const res = await request(app.getHttpServer())
 .get('/exports/xxx')
 .expect('Content-Type', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet; charset=utf-8')
 .buffer()
 .parse(binaryParser)
 assert.ok(Buffer.isBuffer(res.body))
 const workbook = XLSX.read(res.body, { type: 'buffer' })
 const sheet = workbook.Sheets[workbook.SheetNames[0]]
 const json = XLSX.utils.sheet_to_json(sheet, { header: 1 })
 expect(json).toEqual([
 ['My first Row', 'My second Row'],
 ['val 1', 50],
 ['val 2', 10]
 ])
 })
 })