Should middleware.compressResponseWriter implements the Unwrap method ? #818
Description
When using http.ResponseController introduced in Go 1.20 with middleware.Compress, an error occurs.
Example of reproduce: https://go.dev/play/p/z_auq0KiEBx
package main
import (
"fmt"
"net/http"
"net/http/httptest"
"testing"
"time"
"github.com/go-chi/chi/v5/middleware"
)
func TestResponseController(t *testing.T) {
handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// use http.ResponseController to customize read deadline
rc := http.NewResponseController(w)
if err := rc.SetReadDeadline(time.Now().Add(time.Minute)); err != nil {
fmt.Printf("failed to set read deadline: %+v", err)
w.WriteHeader(500)
return
}
w.WriteHeader(200)
})
t.Run("works", func(t *testing.T) {
svr := httptest.NewServer(
handler,
)
t.Cleanup(svr.Close)
resp, _ := http.Get(svr.URL)
// assert status code
if g, w := resp.StatusCode, 200; g != w {
t.Errorf("\ngot :%v\nwant:%v", g, w)
}
})
t.Run("works with the compress middleware", func(t *testing.T) {
// use compress middleware
svr := httptest.NewServer(
middleware.NewCompressor(6).Handler(handler),
)
t.Cleanup(svr.Close)
resp, _ := http.Get(svr.URL)
// assert status code
if g, w := resp.StatusCode, 200; g != w {
t.Errorf("\ngot :%v\nwant:%v", g, w)
}
})
}Results:
=== RUN TestResponseController
=== RUN TestResponseController/works
=== RUN TestResponseController/works_with_the_compress_middleware
failed to set read deadline: feature not supported prog_test.go:46:
got :500
want:200
--- FAIL: TestResponseController (30.00s)
--- PASS: TestResponseController/works (30.00s)
--- FAIL: TestResponseController/works_with_the_compress_middleware (0.00s)
FAIL
This is because http.ResponseController requires ResponseWriter to implement the Unwrap method that returns the original ResponseWriter. See the following code in Go 1.20 source code:
https://cs.opensource.google/go/go/+/refs/tags/go1.20.3:src/net/http/responsecontroller.go;l=23-24
// The ResponseWriter should be the original value passed to the Handler.ServeHTTP method,
// or have an Unwrap method returning the original ResponseWriter.https://cs.opensource.google/go/go/+/refs/tags/go1.20.3:src/net/http/responsecontroller.go;l=79-96
// SetReadDeadline sets the deadline for reading the entire request, including the body.
// Reads from the request body after the deadline has been exceeded will return an error.
// A zero value means no deadline.
//
// Setting the read deadline after it has been exceeded will not extend it.
func (c *ResponseController) SetReadDeadline(deadline time.Time) error {
rw := c.rw
for {
switch t := rw.(type) {
case interface{ SetReadDeadline(time.Time) error }:
return t.SetReadDeadline(deadline)
case rwUnwrapper:
rw = t.Unwrap()
default:
return errNotSupported()
}
}
}To solve this issue, we need to implement the Unwrap method in middleware.compressResponseWriter.
Note that middleware.basicWriter, which is returned by middleware.NewWrapResponseWriter, already implements the Unwrap method, so this issue does not occur with it.