response_writer: support http/2 push (#188)

* add http/2 push support

* Update method return suggested by unknown at response_writer.go

Co-Authored-By: ᴜɴᴋɴᴡᴏɴ <u@gogs.io>

* usage of errors.New

* Update response_writer.go

Co-authored-by: ᴜɴᴋɴᴡᴏɴ <u@gogs.io>

response_writer.go

@@ -16,6 +16,7 @@ package macaron
 
 import (
 	"bufio"
+	"errors"
 	"fmt"
 	"net"
 	"net/http"
@@ -27,6 +28,7 @@ import (
 type ResponseWriter interface {
 	http.ResponseWriter
 	http.Flusher
+	http.Pusher
 	// Status returns the status code of the response or 0 if the response has not been written.
 	Status() int
 	// Written returns whether or not the ResponseWriter has been written.
@@ -91,7 +93,7 @@ func (rw *responseWriter) Before(before BeforeFunc) {
 func (rw *responseWriter) Hijack() (net.Conn, *bufio.ReadWriter, error) {
 	hijacker, ok := rw.ResponseWriter.(http.Hijacker)
 	if !ok {
-		return nil, nil, fmt.Errorf("the ResponseWriter doesn't support the Hijacker interface")
+		return nil, nil, errors.New("the ResponseWriter doesn't support the Hijacker interface")
 	}
 	return hijacker.Hijack()
 }
@@ -112,3 +114,11 @@ func (rw *responseWriter) Flush() {
 		flusher.Flush()
 	}
 }
+
+func (rw *responseWriter) Push(target string, opts *http.PushOptions) error {
+	pusher, ok := rw.ResponseWriter.(http.Pusher)
+	if !ok {
+		return errors.New("the ResponseWriter doesn't support the Pusher interface")
+	}
+	return pusher.Push(target, opts)
+}

response_writer_test.go

@@ -185,4 +185,11 @@ func Test_ResponseWriter(t *testing.T) {
 		So(resp.Code, ShouldEqual, http.StatusOK)
 		So(resp.Body.String(), ShouldEqual, "data: Hello\n\ndata: Hello\n\n")
 	})
+
+	Convey("Response writer with http/2 push", t, func() {
+		resp := httptest.NewRecorder()
+		rw := NewResponseWriter("GET", resp)
+		_, ok := rw.(http.Pusher)
+		So(ok, ShouldBeTrue)
+	})
 }