Better debug logging + unit tests

debug_test.go

@@ -5,11 +5,17 @@
 package gin
 
 import (
+	"bytes"
+	"errors"
+	"io"
+	"log"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 )
 
+var cachedDebugLogger *log.Logger = nil
+
 // TODO
 // func debugRoute(httpMethod, absolutePath string, handlers HandlersChain) {
 // func debugPrint(format string, values ...interface{}) {
@@ -22,3 +28,52 @@ func TestIsDebugging(t *testing.T) {
 	SetMode(TestMode)
 	assert.False(t, IsDebugging())
 }
+
+func TestDebugPrint(t *testing.T) {
+	var w bytes.Buffer
+	setup(&w)
+	defer teardown()
+
+	SetMode(ReleaseMode)
+	debugPrint("DEBUG this!")
+	SetMode(TestMode)
+	debugPrint("DEBUG this!")
+	assert.Empty(t, w.String())
+
+	SetMode(DebugMode)
+	debugPrint("these are %d %s\n", 2, "error messages")
+	assert.Equal(t, w.String(), "[GIN-debug] these are 2 error messages\n")
+}
+
+func TestDebugPrintError(t *testing.T) {
+	var w bytes.Buffer
+	setup(&w)
+	defer teardown()
+
+	SetMode(DebugMode)
+	debugPrintError(nil)
+	assert.Empty(t, w.String())
+
+	debugPrintError(errors.New("this is an error"))
+	assert.Equal(t, w.String(), "[GIN-debug] [ERROR] this is an error\n")
+}
+
+func setup(w io.Writer) {
+	SetMode(DebugMode)
+	if cachedDebugLogger == nil {
+		cachedDebugLogger = debugLogger
+		debugLogger = log.New(w, debugLogger.Prefix(), 0)
+	} else {
+		panic("setup failed")
+	}
+}
+
+func teardown() {
+	SetMode(TestMode)
+	if cachedDebugLogger != nil {
+		debugLogger = cachedDebugLogger
+		cachedDebugLogger = nil
+	} else {
+		panic("teardown failed")
+	}
+}