unable to verify zip response from get

We have written NodeJS based express application. REST API is defined as following:

```
router.get('/module/:id/', async (req, res ) => {
try {

var moduleid = req.params.id

const module = await ModuleMaster.findById(moduleid)

if(!module || !module.modulefile){
throw new Error('Module does not exist')
}
res.set('Content-Type','application/zip')
res.send(module.modulefile)
} catch (error) {
res.status(404).send(error.Message)
}
})

```
Above function is successfully returning file is being tested in browser and postman.

As part of automation, we have written following Jest script to test the functionality of receiving file.

```
const request = require('supertest')
responseFromFileFAPI = await request(app).get('/module/1')
.expect(200)
expect(responseFromFileFAPI.body).not.toBeNull()
expect(responseFromFileFAPI.body.Buffer)

```
All above expect are passing however I am not sure how can I convert the response to zip format so that I can use it to compare with original file?