responder: skip status lookup when request is nil

responder.go

@@ -59,32 +59,37 @@ func DefaultResponder(w http.ResponseWriter, r *http.Request, v interface{}) {
 	}
 }
 
+// writeStatus writes a previously stored Status() hint. A nil request is
+// allowed so wrappers can call JSON/XML/etc. after writing the header themselves.
+func writeStatus(w http.ResponseWriter, r *http.Request) {
+	if r == nil {
+		return
+	}
+	if status, ok := r.Context().Value(StatusCtxKey).(int); ok {
+		w.WriteHeader(status)
+	}
+}
+
 // PlainText writes a string to the response, setting the Content-Type as
 // text/plain.
 func PlainText(w http.ResponseWriter, r *http.Request, v string) {
 	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
-	if status, ok := r.Context().Value(StatusCtxKey).(int); ok {
-		w.WriteHeader(status)
-	}
+	writeStatus(w, r)
 	w.Write([]byte(v)) //nolint:errcheck
 }
 
 // Data writes raw bytes to the response, setting the Content-Type as
 // application/octet-stream.
 func Data(w http.ResponseWriter, r *http.Request, v []byte) {
 	w.Header().Set("Content-Type", "application/octet-stream")
-	if status, ok := r.Context().Value(StatusCtxKey).(int); ok {
-		w.WriteHeader(status)
-	}
+	writeStatus(w, r)
 	w.Write(v) //nolint:errcheck
 }
 
 // HTML writes a string to the response, setting the Content-Type as text/html.
 func HTML(w http.ResponseWriter, r *http.Request, v string) {
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
-	if status, ok := r.Context().Value(StatusCtxKey).(int); ok {
-		w.WriteHeader(status)
-	}
+	writeStatus(w, r)
 	w.Write([]byte(v)) //nolint:errcheck
 }
 
@@ -100,9 +105,7 @@ func JSON(w http.ResponseWriter, r *http.Request, v interface{}) {
 	}
 
 	w.Header().Set("Content-Type", "application/json")
-	if status, ok := r.Context().Value(StatusCtxKey).(int); ok {
-		w.WriteHeader(status)
-	}
+	writeStatus(w, r)
 	w.Write(buf.Bytes()) //nolint:errcheck
 }
 
@@ -117,9 +120,7 @@ func XML(w http.ResponseWriter, r *http.Request, v interface{}) {
 	}
 
 	w.Header().Set("Content-Type", "application/xml; charset=utf-8")
-	if status, ok := r.Context().Value(StatusCtxKey).(int); ok {
-		w.WriteHeader(status)
-	}
+	writeStatus(w, r)
 
 	// Try to find <?xml header in first 100 bytes (just in case there're some XML comments).
 	findHeaderUntil := len(b)

responder_test.go

@@ -0,0 +1,70 @@
+package render
+
+import (
+	"encoding/xml"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func TestJSONNilRequest(t *testing.T) {
+	w := httptest.NewRecorder()
+	w.WriteHeader(http.StatusCreated)
+	JSON(w, nil, map[string]string{"field": "test"})
+	if w.Code != http.StatusCreated {
+		t.Fatalf("status=%d want %d", w.Code, http.StatusCreated)
+	}
+	got := strings.TrimSpace(w.Body.String())
+	if got != `{"field":"test"}` {
+		t.Fatalf("body=%q", got)
+	}
+	if ct := w.Header().Get("Content-Type"); ct != "application/json" {
+		t.Fatalf("Content-Type=%q", ct)
+	}
+}
+
+func TestXMLNilRequest(t *testing.T) {
+	type payload struct {
+		XMLName xml.Name `xml:"item"`
+		Field   string   `xml:"field"`
+	}
+	w := httptest.NewRecorder()
+	XML(w, nil, payload{Field: "test"})
+	if w.Code != http.StatusOK {
+		t.Fatalf("status=%d want %d", w.Code, http.StatusOK)
+	}
+	if !strings.Contains(w.Body.String(), "<field>test</field>") {
+		t.Fatalf("body=%q", w.Body.String())
+	}
+}
+
+func TestPlainTextDataHTMLNilRequest(t *testing.T) {
+	w := httptest.NewRecorder()
+	PlainText(w, nil, "hello")
+	if w.Body.String() != "hello" {
+		t.Fatalf("plaintext body=%q", w.Body.String())
+	}
+
+	w = httptest.NewRecorder()
+	Data(w, nil, []byte("raw"))
+	if w.Body.String() != "raw" {
+		t.Fatalf("data body=%q", w.Body.String())
+	}
+
+	w = httptest.NewRecorder()
+	HTML(w, nil, "<p>ok</p>")
+	if w.Body.String() != "<p>ok</p>" {
+		t.Fatalf("html body=%q", w.Body.String())
+	}
+}
+
+func TestJSONStillHonorsStatusHint(t *testing.T) {
+	w := httptest.NewRecorder()
+	r := httptest.NewRequest(http.MethodGet, "/", nil)
+	Status(r, http.StatusAccepted)
+	JSON(w, r, map[string]string{"ok": "yes"})
+	if w.Code != http.StatusAccepted {
+		t.Fatalf("status=%d want %d", w.Code, http.StatusAccepted)
+	}
+}