fix errcheck warnings (#1739)

render/json.go

@@ -67,8 +67,8 @@ func WriteJSON(w http.ResponseWriter, obj interface{}) error {
 	if err != nil {
 		return err
 	}
-	w.Write(jsonBytes)
-	return nil
+	_, err = w.Write(jsonBytes)
+	return err
 }
 
 // Render (IndentedJSON) marshals the given interface object and writes it with custom ContentType.
@@ -78,8 +78,8 @@ func (r IndentedJSON) Render(w http.ResponseWriter) error {
 	if err != nil {
 		return err
 	}
-	w.Write(jsonBytes)
-	return nil
+	_, err = w.Write(jsonBytes)
+	return err
 }
 
 // WriteContentType (IndentedJSON) writes JSON ContentType.
@@ -96,10 +96,13 @@ func (r SecureJSON) Render(w http.ResponseWriter) error {
 	}
 	// if the jsonBytes is array values
 	if bytes.HasPrefix(jsonBytes, []byte("[")) && bytes.HasSuffix(jsonBytes, []byte("]")) {
-		w.Write([]byte(r.Prefix))
+		_, err = w.Write([]byte(r.Prefix))
+		if err != nil {
+			return err
+		}
 	}
-	w.Write(jsonBytes)
-	return nil
+	_, err = w.Write(jsonBytes)
+	return err
 }
 
 // WriteContentType (SecureJSON) writes JSON ContentType.
@@ -116,15 +119,27 @@ func (r JsonpJSON) Render(w http.ResponseWriter) (err error) {
 	}
 
 	if r.Callback == "" {
-		w.Write(ret)
-		return nil
+		_, err = w.Write(ret)
+		return err
 	}
 
 	callback := template.JSEscapeString(r.Callback)
-	w.Write([]byte(callback))
-	w.Write([]byte("("))
-	w.Write(ret)
-	w.Write([]byte(")"))
+	_, err = w.Write([]byte(callback))
+	if err != nil {
+		return err
+	}
+	_, err = w.Write([]byte("("))
+	if err != nil {
+		return err
+	}
+	_, err = w.Write(ret)
+	if err != nil {
+		return err
+	}
+	_, err = w.Write([]byte(")"))
+	if err != nil {
+		return err
+	}
 
 	return nil
 }
@@ -151,8 +166,8 @@ func (r AsciiJSON) Render(w http.ResponseWriter) (err error) {
 		buffer.WriteString(cvt)
 	}
 
-	w.Write(buffer.Bytes())
-	return nil
+	_, err = w.Write(buffer.Bytes())
+	return err
 }
 
 // WriteContentType (AsciiJSON) writes JSON ContentType.

render/protobuf.go

@@ -26,8 +26,8 @@ func (r ProtoBuf) Render(w http.ResponseWriter) error {
 		return err
 	}
 
-	w.Write(bytes)
-	return nil
+	_, err = w.Write(bytes)
+	return err
 }
 
 // WriteContentType (ProtoBuf) writes ProtoBuf ContentType.

render/render_test.go

@@ -71,7 +71,7 @@ func TestRenderJSONPanics(t *testing.T) {
 	data := make(chan int)
 
 	// json: unsupported type: chan int
-	assert.Panics(t, func() { (JSON{data}).Render(w) })
+	assert.Panics(t, func() { assert.NoError(t, (JSON{data}).Render(w)) })
 }
 
 func TestRenderIndentedJSON(t *testing.T) {
@@ -335,7 +335,7 @@ func TestRenderRedirect(t *testing.T) {
 	}
 
 	w = httptest.NewRecorder()
-	assert.Panics(t, func() { data2.Render(w) })
+	assert.Panics(t, func() { assert.NoError(t, data2.Render(w)) })
 
 	// only improve coverage
 	data2.WriteContentType(w)

render/text.go

@@ -20,8 +20,7 @@ var plainContentType = []string{"text/plain; charset=utf-8"}
 
 // Render (String) writes data with custom ContentType.
 func (r String) Render(w http.ResponseWriter) error {
-	WriteString(w, r.Format, r.Data)
-	return nil
+	return WriteString(w, r.Format, r.Data)
 }
 
 // WriteContentType (String) writes Plain ContentType.
@@ -30,11 +29,12 @@ func (r String) WriteContentType(w http.ResponseWriter) {
 }
 
 // WriteString writes data according to its format and write custom ContentType.
-func WriteString(w http.ResponseWriter, format string, data []interface{}) {
+func WriteString(w http.ResponseWriter, format string, data []interface{}) (err error) {
 	writeContentType(w, plainContentType)
 	if len(data) > 0 {
-		fmt.Fprintf(w, format, data...)
+		_, err = fmt.Fprintf(w, format, data...)
 		return
 	}
-	io.WriteString(w, format)
+	_, err = io.WriteString(w, format)
+	return
 }

render/yaml.go

@@ -26,8 +26,8 @@ func (r YAML) Render(w http.ResponseWriter) error {
 		return err
 	}
 
-	w.Write(bytes)
-	return nil
+	_, err = w.Write(bytes)
+	return err
 }
 
 // WriteContentType (YAML) writes YAML ContentType for response.