Getting pdf file from api response

Question

I am calling an api and getting pdf in return.

fetch(`api` + guid, {
   method: "GET",
   headers: {
    "Accept": "application/octet-stream",
    "Authorization": "Bearer " + token,
   },
   responseType: 'arraybuffer',
})
.then((res) => res.text())
.then((data) => {
    fs.writeFileSync('file.pdf', data);
});

I get the pdf file but the issue is the pdf file is always empty. But when I accept response as json, it works fine.

I found similar problems like this but none of the solution worked for me yet.

It would be great if someone can point out the issue.

Answer 1

I found the issue. As I am using fetch not Axios. We cannot pass responseType as Fetch's option.

fetch(`api` + guid, {
   method: "GET",
   headers: {
    "Accept": "application/octet-stream",
    "Authorization": "Bearer " + token,
   },
   // responseType: 'arraybuffer' //#1 remove this,
})

Instead the response in itself can be passed as arraybuffer as below.

.then((res) => res.arraybuffer())

instead of

.then((res) => res.text())

Now instead of directly using the response to write our pdf file. We can change the data to base64 string and decode it back again to create our pdf file. I used base64ToPdf npm package to handle that.

.then(data => {
  var base64Str = Buffer.from(data).toString('base64');
  base64.base64Decode(base64Str, "file.pdf");
})

I hope this help others. :)