如何获取数组缓冲区对象的 MIME 类型？

Question

I am working on an API which is fetching file data as arraybuffer type. What my main question is there any of knowing what is the mime type of the file from the arraybuffer as I need to convert it to BLOB to view the file.

var file1 = new Blob([response], { type: file.type });
var fileURL = URL.createObjectURL(file1);

In the above code snippet, the response is an arraybuffer and the mime type I got is by storing it while uploading in a variable. But now the scenario is I don't have any mime type in my hand so I need a way to get it.

This is my response header:

And this is my response body sample:

Can anyone suggest me anything ?

Answer 1

I found this package below which is very interesting. It parses the array buffer/blob/stream and try to guess its extension and mime type if it were a file. Obviously it is not exhaustive but you can find the extension list in the readme. Works on node and browser. Works for my needs though.

Here is the repo link : https://github.com/sindresorhus/file-type