Merge 8dbee163b27a5202c73a920d79129edf179de444 into a481ee2897af1e368de5c919fbeb21b89aa26fc7

logger.go

@@ -11,6 +11,7 @@ import (
 	"os"
 	"time"
 
+	"github.com/gin-gonic/gin/internal/bytesconv"
 	"github.com/mattn/go-isatty"
 )
 
@@ -37,7 +38,7 @@ var consoleColorMode = autoColor
 
 // LoggerConfig defines the config for Logger middleware.
 type LoggerConfig struct {
-	// Optional. Default value is gin.defaultLogFormatter
+	// Formatter is optional, the default value is gin.defaultLogFormatter
 	Formatter LogFormatter
 
 	// Output is a writer where logs are written.
@@ -266,7 +267,9 @@ func LoggerWithConfig(conf LoggerConfig) HandlerFunc {
 
 			param.Path = path
 
-			fmt.Fprint(out, formatter(param))
+			if _, err := out.Write(bytesconv.StringToBytes(formatter(param))); err != nil {
+				debugPrintError(err)
+			}
 		}
 	}
 }

logger_test.go

@@ -147,6 +147,15 @@ func TestLoggerWithConfig(t *testing.T) {
 	assert.Contains(t, buffer.String(), "/notfound")
 }
 
+func TestLoggerWithConfigWriteError(t *testing.T) {
+	w := &mockErrWriter{}
+	router := New()
+	router.Use(LoggerWithConfig(LoggerConfig{Output: w}))
+	router.GET("/example", func(c *Context) {})
+	PerformRequest(router, "GET", "/example?a=100")
+	assert.True(t, w.triggerErrorWrite)
+}
+
 func TestLoggerWithFormatter(t *testing.T) {
 	buffer := new(strings.Builder)
 
@@ -434,3 +443,12 @@ func TestForceConsoleColor(t *testing.T) {
 	// reset console color mode.
 	consoleColorMode = autoColor
 }
+
+type mockErrWriter struct {
+	triggerErrorWrite bool
+}
+
+func (w *mockErrWriter) Write(p []byte) (n int, err error) {
+	w.triggerErrorWrite = true
+	return 0, errors.New("test error writer")
+}