added negroni adapters

Author: jonasi

adapters.go

@@ -10,11 +10,8 @@ import (
 // into a mohttp.Handler
 func FromHTTPMiddleware(fn func(http.Handler) http.Handler) Handler {
 	return HandlerFunc(func(c context.Context) {
-		fn(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			c = WithRequest(c, r)
-			c = WithResponseWriter(c, w)
-			Next(c)
-		})).ServeHTTP(GetResponseWriter(c), GetRequest(c))
+		h := fn(mkNextHTTPHandler(c))
+		h.ServeHTTP(GetResponseWriter(c), GetRequest(c))
 	})
 }
 
@@ -26,3 +23,31 @@ func FromHTTPHandler(handler http.Handler) Handler {
 		Next(c)
 	})
 }
+
+type NegronHandler interface {
+	ServeHTTP(http.ResponseWriter, *http.Request, http.HandlerFunc)
+}
+
+type NegroniHandlerFunc func(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc)
+
+func (fn NegroniHandlerFunc) ServeHTTP(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
+	fn(rw, r, next)
+}
+
+func FromNegroniHandler(n NegronHandler) Handler {
+	return HandlerFunc(func(c context.Context) {
+		n.ServeHTTP(GetResponseWriter(c), GetRequest(c), mkNextHTTPHandler(c))
+	})
+}
+
+func FromNegroniHandlerFunc(fn func(http.ResponseWriter, *http.Request, http.HandlerFunc)) Handler {
+	return FromNegroniHandler(NegroniHandlerFunc(fn))
+}
+
+func mkNextHTTPHandler(c context.Context) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		c = WithRequest(c, r)
+		c = WithResponseWriter(c, w)
+		Next(c)
+	}
+}