Implement Unwrap() for responseWriterDelegator (#1480)

If the ResponseWriter implements any of the following methods,
the ResponseController will call them as appropriate:

Flush()
FlushError() error // alternative Flush returning an error
Hijack() (net.Conn, *bufio.ReadWriter, error)
SetReadDeadline(deadline time.Time) error
SetWriteDeadline(deadline time.Time) error
EnableFullDuplex() error

If the ResponseWriter doesn't implement the methods,
the ResponseController will call Unwrap() method until it
finds a ResponseWriter in the chain

This commit implements Unwrap() method to simply return the
wrapped ResponseWriter

Signed-off-by: Igor Drozdov <ihardrozdov@gmail.com>
This commit is contained in:
Igor Drozdov 2024-03-28 14:42:34 +01:00 committed by GitHub
parent 50ab457fb7
commit 93cf5d4f5f
No known key found for this signature in database
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2 changed files with 84 additions and 0 deletions

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@ -76,6 +76,12 @@ func (r *responseWriterDelegator) Write(b []byte) (int, error) {
return n, err
}
// Unwrap lets http.ResponseController get the underlying http.ResponseWriter,
// by implementing the [rwUnwrapper](https://cs.opensource.google/go/go/+/refs/tags/go1.21.4:src/net/http/responsecontroller.go;l=42-44) interface.
func (r *responseWriterDelegator) Unwrap() http.ResponseWriter {
return r.ResponseWriter
}
type (
closeNotifierDelegator struct{ *responseWriterDelegator }
flusherDelegator struct{ *responseWriterDelegator }

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@ -0,0 +1,78 @@
// Copyright 2024 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package promhttp
import (
"net/http"
"testing"
"time"
)
type responseWriter struct {
flushErrorCalled bool
setWriteDeadlineCalled time.Time
setReadDeadlineCalled time.Time
}
func (rw *responseWriter) Header() http.Header {
return nil
}
func (rw *responseWriter) Write(p []byte) (int, error) {
return 0, nil
}
func (rw *responseWriter) WriteHeader(statusCode int) {
}
func (rw *responseWriter) FlushError() error {
rw.flushErrorCalled = true
return nil
}
func (rw *responseWriter) SetWriteDeadline(deadline time.Time) error {
rw.setWriteDeadlineCalled = deadline
return nil
}
func (rw *responseWriter) SetReadDeadline(deadline time.Time) error {
rw.setReadDeadlineCalled = deadline
return nil
}
func TestResponseWriterDelegatorUnwrap(t *testing.T) {
w := &responseWriter{}
rwd := &responseWriterDelegator{ResponseWriter: w}
if rwd.Unwrap() != w {
t.Error("unwrapped responsewriter must equal to the original responsewriter")
}
controller := http.NewResponseController(rwd)
if err := controller.Flush(); err != nil || !w.flushErrorCalled {
t.Error("FlushError must be propagated to the original responsewriter")
}
timeNow := time.Now()
if err := controller.SetWriteDeadline(timeNow); err != nil || w.setWriteDeadlineCalled != timeNow {
t.Error("SetWriteDeadline must be propagated to the original responsewriter")
}
if err := controller.SetReadDeadline(timeNow); err != nil || w.setReadDeadlineCalled != timeNow {
t.Error("SetReadDeadline must be propagated to the original responsewriter")
}
}