feat(func): implement Skipper functionality for logging configuration

zap.go

@@ -18,6 +18,9 @@ import (
 
 type Fn func(c *gin.Context) []zapcore.Field
 
+// Skipper is a function to skip logs based on provided Context
+type Skipper func(c *gin.Context) bool
+
 // ZapLogger is the minimal logger interface compatible with zap.Logger
 type ZapLogger interface {
 	Info(msg string, fields ...zap.Field)
@@ -31,6 +34,9 @@ type Config struct {
 	SkipPaths    []string
 	Context      Fn
 	DefaultLevel zapcore.Level
+	// skip is a Skipper that indicates which logs should not be written.
+	// Optional.
+	Skipper Skipper
 }
 
 // Ginzap returns a gin.HandlerFunc (middleware) that logs requests using uber-go/zap.
@@ -58,8 +64,13 @@ func GinzapWithConfig(logger ZapLogger, conf *Config) gin.HandlerFunc {
 		path := c.Request.URL.Path
 		query := c.Request.URL.RawQuery
 		c.Next()
+		track := true
+
+		if _, ok := skipPaths[path]; ok || (conf.Skipper != nil && conf.Skipper(c)) {
+			track = false
+		}
 
-		if _, ok := skipPaths[path]; !ok {
+		if track {
 			end := time.Now()
 			latency := end.Sub(start)
 			if conf.UTC {

zap_test.go

@@ -129,3 +129,46 @@ func TestGinzapWithConfig(t *testing.T) {
 		t.Fatalf("log level should be warn but was %s", logLine.Level.String())
 	}
 }
+
+func TestLoggerSkipper(t *testing.T) {
+	r := gin.New()
+
+	utcLogger, utcLoggerObserved := buildDummyLogger()
+	r.Use(GinzapWithConfig(utcLogger, &Config{
+		TimeFormat: time.RFC3339,
+		UTC:        true,
+		Skipper: func(c *gin.Context) bool {
+			return c.Request.URL.Path == "/no_log"
+		},
+	}))
+
+	r.GET("/test", func(c *gin.Context) {
+		c.JSON(204, nil)
+	})
+
+	r.GET("/no_log", func(c *gin.Context) {
+		c.JSON(204, nil)
+	})
+
+	res1 := httptest.NewRecorder()
+	req1, _ := http.NewRequest("GET", "/test", nil)
+	r.ServeHTTP(res1, req1)
+
+	res2 := httptest.NewRecorder()
+	req2, _ := http.NewRequest("GET", "/no_log", nil)
+	r.ServeHTTP(res2, req2)
+
+	if res2.Code != 204 {
+		t.Fatalf("request /no_log is failed (%d)", res2.Code)
+	}
+
+	if len(utcLoggerObserved.All()) != 1 {
+		t.Fatalf("Log should be 1 line but there're %d", len(utcLoggerObserved.All()))
+	}
+
+	logLine := utcLoggerObserved.All()[0]
+	pathStr := logLine.Context[2].String
+	if pathStr != "/test" {
+		t.Fatalf("logged path should be /test but %s", pathStr)
+	}
+}