[Tips] How to test downloaded Excel file from response #2777

Gist to test the content of an Excel File in a controller (e2e) test, with a lib like supertest:

  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]
      ])
    })
  })

Very cool, thanks for sharing! Server demos like the express example currently recommend opening the page with a browser (or using curl to upload data manually)

Is there a reason why the content type is text/xlsx rather than the typical application/vnd.ms-excel or application/vnd.openxmlformats-officedocument.spreadsheetml.sheet ?

The content type is a mistake of mine, I fix it right now. Thank you 🙏