From 23a88f8df0ccd37ea84ca3ff36f0faf9edbfc9a2 Mon Sep 17 00:00:00 2001
From: Scott Fleckenstein <nullstyle@gmail.com>
Date: Fri, 20 Nov 2015 08:29:27 -0800
Subject: [PATCH] Add `flushWriter` to `mutil.WrapWriter()`

This allows httptest.ResponseRecorder to be wrapped and still maintain
its Flusher compatibility
---
 web/mutil/writer_proxy.go | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/web/mutil/writer_proxy.go b/web/mutil/writer_proxy.go
index d572812..9f6d776 100644
--- a/web/mutil/writer_proxy.go
+++ b/web/mutil/writer_proxy.go
@@ -39,6 +39,9 @@ func WrapWriter(w http.ResponseWriter) WriterProxy {
 	if cn && fl && hj && rf {
 		return &fancyWriter{bw}
 	}
+	if fl {
+		return &flushWriter{bw}
+	}
 	return &bw
 }
 
@@ -123,3 +126,14 @@ var _ http.CloseNotifier = &fancyWriter{}
 var _ http.Flusher = &fancyWriter{}
 var _ http.Hijacker = &fancyWriter{}
 var _ io.ReaderFrom = &fancyWriter{}
+
+type flushWriter struct {
+	basicWriter
+}
+
+func (f *flushWriter) Flush() {
+	fl := f.basicWriter.ResponseWriter.(http.Flusher)
+	fl.Flush()
+}
+
+var _ http.Flusher = &flushWriter{}