NPM module to find the mime type of a file from an extension, and the extension of a file from a mime type
npm install --save mimetype-extension
In your node js application:
var mime_ext = require('mimetype-extension')
Get mime type :
mime_ext.type("png") return "image/png"
mime_ext.type("ttf") return "application/x-font-ttf"
Get extension :
mime_ext.ext("image/png") return "png"
mime_ext.ext("application/x-font-ttf") return "ttf"
So you can do :
res.setHeader('Content-Type', mime_ext.get("js"))