Update content_type.go (#880)

middleware/content_type.go

@@ -6,44 +6,40 @@ import (
 )
 
 // SetHeader is a convenience handler to set a response header key/value
-func SetHeader(key, value string) func(next http.Handler) http.Handler {
+func SetHeader(key, value string) func(http.Handler) http.Handler {
 	return func(next http.Handler) http.Handler {
-		fn := func(w http.ResponseWriter, r *http.Request) {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			w.Header().Set(key, value)
 			next.ServeHTTP(w, r)
-		}
-		return http.HandlerFunc(fn)
+		})
 	}
 }
 
 // AllowContentType enforces a whitelist of request Content-Types otherwise responds
 // with a 415 Unsupported Media Type status.
-func AllowContentType(contentTypes ...string) func(next http.Handler) http.Handler {
+func AllowContentType(contentTypes ...string) func(http.Handler) http.Handler {
 	allowedContentTypes := make(map[string]struct{}, len(contentTypes))
 	for _, ctype := range contentTypes {
 		allowedContentTypes[strings.TrimSpace(strings.ToLower(ctype))] = struct{}{}
 	}
 
 	return func(next http.Handler) http.Handler {
-		fn := func(w http.ResponseWriter, r *http.Request) {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			if r.ContentLength == 0 {
-				// skip check for empty content body
+				// Skip check for empty content body
 				next.ServeHTTP(w, r)
 				return
 			}
 
-			s := strings.ToLower(strings.TrimSpace(r.Header.Get("Content-Type")))
-			if i := strings.Index(s, ";"); i > -1 {
-				s = s[0:i]
-			}
+			s := strings.ToLower(strings.TrimSpace(strings.Split(r.Header.Get("Content-Type"), ";")[0]))
 
 			if _, ok := allowedContentTypes[s]; ok {
 				next.ServeHTTP(w, r)
 				return
 			}
 
 			w.WriteHeader(http.StatusUnsupportedMediaType)
-		}
-		return http.HandlerFunc(fn)
+		})
 	}
 }
+