dat:// - look for file extensions based on Accept header

Author: pfrazee

dat/protocol.js

@@ -213,7 +213,10 @@ exports.electronHandler = async function (request, respond) {
     await tryStat(filepath)
   } else {
     await tryStat(filepath)
-    await tryStat(filepath + '.html') // fallback to .html
+    for (let ext of mime.acceptHeaderExtensions(request.headers.Accept)) {
+      // fallback to different requested headers
+      await tryStat(filepath + ext)
+    }
     if (entry && entry.isDirectory()) {
       // unexpected directory, give the .html fallback a chance
       let dirEntry = entry

lib/mime.js

@@ -63,6 +63,16 @@ exports.isFileContentBinary = async function (fsInstance, filepath) {
   })
 }
 
+// for a given HTTP accept header, provide a list of file-extensions to try
+exports.acceptHeaderExtensions = function (accept) {
+  var exts = []
+  accept = accept.split(',')
+  if (accept.includes('text/html') || (accept.length === 1 && accept[0] === '*/*')) exts.push('.html')
+  if (accept.includes('text/css')) exts.push('.css')
+  if (accept.includes('image/*') || accept.includes('image/apng')) exts = exts.concat(['.png', '.jpg', '.jpeg', '.gif'])
+  return exts
+}
+
 // pulled from https://github.com/gjtorikian/isBinaryFile
 function isBinaryCheck (bytes) {
   var size = bytes.length