implement HEAD and GET

src/index.coffee

@@ -10,10 +10,24 @@ addEventListener 'fetch', (event) =>
 handleRequest = ({ request }) ->
   if request.method is "PUT"
     return handlePUT request
+  else if request.method is "HEAD"
+    return handleHEAD request
+  else if request.method is "GET"
+    return handleGET request
 
   return new Response "Not Found",
     status: 404
 
+handleHEAD = (request) ->
+  url = new URL request.url
+
+  return await s3.headObject url.pathname[1...], {}
+
+handleGET = (request) ->
+  url = new URL request.url
+
+  return await s3.getObject url.pathname[1...], {}
+
 handlePUT = (request) ->
   url = new URL request.url
   # Start from the highest version number