Adding support for default http-messages

README.md

@@ -73,6 +73,34 @@ See [here](https://httpstatuses.com/) for a complete list of HTTP responses, alo
 
 Please submit a PR if you want to add to this list. Only the most common response types have been included.
 
+## To Long, Don't Write
+
+Sometimes you don't need to return a specific content-message but don't want the response body to be empty.
+In this case you can use the `DefaultMessage()` for responding with json containing the default message for the corresponding status code.
+
+```go
+package main
+
+import (
+    "net/http"
+    resp "github.com/nicklaw5/go-respond"
+)
+
+func main() {
+    http.HandleFunc("/api/users", func(w http.ResponseWriter, r *http.Request) {
+        // ...
+        if !authenticated {
+            resp.NewResponse(w).DefaultMessage().
+                Unauthorized(nil)
+        }
+        // ...
+    })
+    http.ListenAndServe(":8080", nil)
+}
+```
+
+Would respond with `{"status":401,"message":"Unauthorized"}`
+
 ## Handling Errors
 
 The best option for handling errors that may occur while marshalling the JSON response, is to use [Negroni's Recovery middleware](https://github.com/urfave/negroni#recovery). Here's an example:

go.mod

@@ -0,0 +1,3 @@
+module github.com/nicklaw5/go-respond
+
+go 1.12

response.go

@@ -7,8 +7,15 @@ import (
 
 // Response is the HTTP response
 type Response struct {
-	Writer  http.ResponseWriter
-	Headers map[string]string
+	Writer     http.ResponseWriter
+	Headers    map[string]string
+	DefMessage bool
+}
+
+// DefaultMessageResponse is for transporting a default http message
+type DefaultMessageResponse struct {
+	Status  int    `json:"status"`
+	Message string `json:"message"`
 }
 
 // NewResponse creates and returns a new response
@@ -21,6 +28,11 @@ func NewResponse(w http.ResponseWriter) *Response {
 	}
 }
 
+func (resp *Response) DefaultMessage() *Response {
+	resp.DefMessage = true
+	return resp
+}
+
 // DeleteHeader deletes a single header from the response
 func (resp *Response) DeleteHeader(key string) *Response {
 	resp.Writer.Header().Del(key)
@@ -41,16 +53,24 @@ func (resp *Response) writeResponse(code int, v interface{}) error {
 
 	resp.writeStatusCode(code)
 
+	if v == nil && resp.DefMessage {
+		v = DefaultMessageResponse{
+			Status:  code,
+			Message: http.StatusText(code),
+		}
+	}
+
 	if v != nil {
 		body, err := json.Marshal(v)
 		if err != nil {
 			panic(err)
 		}
-
+		// can just return an error when connection is hijacked or content-size is longer then declared.
 		if _, err := resp.Writer.Write(body); err != nil {
 			panic(err)
 		}
 	}
+
 	return nil
 }
 

response_test.go

@@ -3,11 +3,10 @@ package respond_test
 import (
 	"errors"
 	"fmt"
+	resp "github.com/nicklaw5/go-respond"
 	"net/http"
 	"net/http/httptest"
 	"testing"
-
-	resp "github.com/nicklaw5/go-respond"
 )
 
 func newRequest(t *testing.T, method string) *http.Request {
@@ -42,6 +41,42 @@ func validateResponseHeader(responseHeaderValue string, expectedHeaderValue stri
 	return nil
 }
 
+func TestDefaultMessage(t *testing.T) {
+	t.Parallel()
+
+	req := newRequest(t, "GET")
+
+	rr := httptest.NewRecorder()
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		resp.NewResponse(w).DefaultMessage().
+			Unauthorized(nil)
+	})
+	handler.ServeHTTP(rr, req)
+
+	if err := validateResponseBody(rr.Body.String(), "{\"status\":401,\"message\":\"Unauthorized\"}"); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestRespondInvalidType(t *testing.T) {
+	defer func() {
+		if r := recover(); r == nil {
+			t.Errorf("responding with invalid type (channel) should have caused a panic")
+		}
+	}()
+
+	t.Parallel()
+
+	req := newRequest(t, "GET")
+
+	rr := httptest.NewRecorder()
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		resp.NewResponse(w).DefaultMessage().
+			Unauthorized(make(chan int))
+	})
+	handler.ServeHTTP(rr, req)
+}
+
 func TestContentTypeHeader(t *testing.T) {
 	t.Parallel()