I have created a buffer from a file which can be pdf, jpg or any other format. Now I want to detect if the buffer is of the pdf file or any other file.

request({ url, encoding: null }, (err, resp, buffer) => {

    hashFromFilebuffer('sha256', buffer).then(function (result) {

        console.log(result)

    }).catch(function (error) {

        console.log(error)

    });

});