Use new methodNotAllowedHandler

Author: isoos

app/lib/frontend/handlers/documentation.dart

@@ -25,8 +25,7 @@ import '../../shared/urls.dart';
 Future<shelf.Response> documentationHandler(shelf.Request request) async {
   final requestMethod = request.method.toUpperCase();
   if (requestMethod != 'HEAD' && requestMethod != 'GET') {
-    // TODO: Should probably be "method not supported"!
-    return notFoundHandler(request);
+    return methodNotAllowedHandler(request);
   }
 
   final docFilePath = parseRequestUri(request.requestedUri);

app/lib/shared/handlers.dart

@@ -101,6 +101,13 @@ shelf.Response notFoundHandler(
   return htmlResponse(body, status: 404, headers: headers);
 }
 
+shelf.Response methodNotAllowedHandler(
+  shelf.Request request, {
+  Map<String, Object>? headers,
+}) {
+  return shelf.Response(405, body: 'Method Not Allowed', headers: headers);
+}
+
 shelf.Response rejectRobotsHandler(shelf.Request request) =>
     shelf.Response.ok('User-agent: *\nDisallow: /\n');