I am basically doing this:

if (event.kind == 5393) {

response.setHeader('content-type', "text/css")

response.send(event.content)

} else if (event.kind == 5392) {

response.setHeader('content-type', "text/html")

response.send(event.content)

} else if (event.kind == 5394) {

response.setHeader('content-type', "text/javascript")

response.send(event.content)

}