Updated middleware example to return error format that fn understands.

api/server/middleware.go

@@ -91,6 +91,7 @@ func (c *middlewareContextImpl) serveNext() {
 		logrus.WithError(err).Warnln("Middleware error")
 		// todo: might be a good idea to check if anything is written yet, and if not, output the error: simpleError(err)
 		// see: http://stackoverflow.com/questions/39415827/golang-http-check-if-responsewriter-has-been-written
+		c.ginContext.Error(err)
 		c.ginContext.Abort()
 		return
 	}
@@ -110,6 +111,7 @@ func (s *Server) middlewareWrapperFunc(ctx context.Context) gin.HandlerFunc {
 		if len(s.middlewares) == 0 {
 			return
 		}
+		// TODO: we should get rid of this, gin context and middleware context both implement context, don't need a third one here
 		ctx = c.MustGet("ctx").(context.Context)
 		fctx := &middlewareContextImpl{Context: ctx}
 		// add this context to gin context so we can grab it later

examples/middleware/main.go

@@ -40,8 +40,10 @@ func (h *CustomMiddleware) Serve(ctx server.MiddlewareContext, w http.ResponseWr
 	// check auth header
 	tokenHeader := strings.SplitN(r.Header.Get("Authorization"), " ", 3)
 	if len(tokenHeader) < 2 || tokenHeader[1] != "KlaatuBaradaNikto" {
+		w.Header().Set("Content-Type", "application/json")
 		w.WriteHeader(http.StatusUnauthorized)
-		m := map[string]string{"error": "Invalid Authorization token. Sorry!"}
+		m2 := map[string]string{"message": "Invalid Authorization token."}
+		m := map[string]map[string]string{"error": m2}
 		json.NewEncoder(w).Encode(m)
 		return errors.New("Invalid authorization token.")
 	}