refactor: remove unnecessary casts to MiddlewareFunc

Author: rmhubbert

header.go

@@ -5,12 +5,12 @@ import "net/http"
 // HeaderMiddleware creates and returns a MiddlewareFunc that will apply all of the headers
 // that have been passed in.
 func HeaderMiddleware(headers map[string]string) MiddlewareFunc {
-	return MiddlewareFunc(func(next Handler) Handler {
+	return func(next Handler) Handler {
 		return HandlerFunc(func(w http.ResponseWriter, r *http.Request) error {
 			for key, value := range headers {
 				w.Header().Add(key, value)
 			}
 			return next.ServeHTTPWithError(w, r)
 		})
-	})
+	}
 }

httperrorhandler.go

@@ -15,7 +15,7 @@ import (
 // error was returned from the handler. This will allow any other middleware to assume
 // that if they have not received an error, then no error has occurred.
 func HTTPErrorHandlerMiddleware(registeredErrors map[error]int) MiddlewareFunc {
-	return MiddlewareFunc(func(next Handler) Handler {
+	return func(next Handler) Handler {
 		return HandlerFunc(func(w http.ResponseWriter, r *http.Request) error {
 			cw := NewCaptureWriter(w)
 			err := next.ServeHTTPWithError(cw, r)
@@ -58,5 +58,5 @@ func HTTPErrorHandlerMiddleware(registeredErrors map[error]int) MiddlewareFunc {
 			Error(w, err.Error(), http.StatusInternalServerError)
 			return NewHTTPError(err, http.StatusInternalServerError)
 		})
-	})
+	}
 }

timeout.go

@@ -36,12 +36,12 @@ func NewTimeout(duration time.Duration, message string) Timeout {
 // TimeoutMiddleware creates, initialises and returns a middleware function that will wrap the next
 // handler in the stack with a timeout handler.
 func TimeoutMiddleware(timeout Timeout) MiddlewareFunc {
-	return MiddlewareFunc(func(next Handler) Handler {
+	return func(next Handler) Handler {
 		return HandlerFunc(func(w http.ResponseWriter, r *http.Request) error {
 			th := NewTimeoutHandler(next, timeout)
 			return th.ServeHTTPWithError(w, r)
 		})
-	})
+	}
 }
 
 // ------------------------------------------------------------------------------------------------