diff --git a/log/helper_test.go b/log/helper_test.go
index 21d8e6972..a9c1a68be 100644
--- a/log/helper_test.go
+++ b/log/helper_test.go
@@ -15,6 +15,10 @@ func TestHelper(t *testing.T) {
 	log.Debug("test debug")
 	log.Debugf("test %s", "debug")
 	log.Debugw("log", "test debug")
+
+	log.Warn("test warn")
+	log.Warnf("test %s", "warn")
+	log.Warnw("log", "test warn")
 }
 
 func TestHelperWithMsgKey(t *testing.T) {
@@ -28,8 +32,11 @@ func TestHelperLevel(t *testing.T) {
 	log := NewHelper(DefaultLogger)
 	log.Debug("test debug")
 	log.Info("test info")
+	log.Infof("test %s", "info")
 	log.Warn("test warn")
 	log.Error("test error")
+	log.Errorf("test %s", "error")
+	log.Errorw("log", "test error")
 }
 
 func BenchmarkHelperPrint(b *testing.B) {
diff --git a/log/level_test.go b/log/level_test.go
new file mode 100644
index 000000000..d36882912
--- /dev/null
+++ b/log/level_test.go
@@ -0,0 +1,95 @@
+package log
+
+import "testing"
+
+func TestLevel_String(t *testing.T) {
+	tests := []struct {
+		name string
+		l    Level
+		want string
+	}{
+		{
+			name: "DEBUG",
+			l:    LevelDebug,
+			want: "DEBUG",
+		},
+		{
+			name: "INFO",
+			l:    LevelInfo,
+			want: "INFO",
+		},
+		{
+			name: "WARN",
+			l:    LevelWarn,
+			want: "WARN",
+		},
+		{
+			name: "ERROR",
+			l:    LevelError,
+			want: "ERROR",
+		},
+		{
+			name: "FATAL",
+			l:    LevelFatal,
+			want: "FATAL",
+		},
+		{
+			name: "other",
+			l:    10,
+			want: "",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := tt.l.String(); got != tt.want {
+				t.Errorf("String() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestParseLevel(t *testing.T) {
+	tests := []struct {
+		name string
+		s    string
+		want Level
+	}{
+		{
+			name: "DEBUG",
+			want: LevelDebug,
+			s:    "DEBUG",
+		},
+		{
+			name: "INFO",
+			want: LevelInfo,
+			s:    "INFO",
+		},
+		{
+			name: "WARN",
+			want: LevelWarn,
+			s:    "WARN",
+		},
+		{
+			name: "ERROR",
+			want: LevelError,
+			s:    "ERROR",
+		},
+		{
+			name: "FATAL",
+			want: LevelFatal,
+			s:    "FATAL",
+		},
+		{
+			name: "other",
+			want: LevelInfo,
+			s:    "other",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := ParseLevel(tt.s); got != tt.want {
+				t.Errorf("ParseLevel() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
diff --git a/log/log_test.go b/log/log_test.go
index 27a25ad6f..dea00f4d6 100644
--- a/log/log_test.go
+++ b/log/log_test.go
@@ -1,6 +1,7 @@
 package log
 
 import (
+	"context"
 	"os"
 	"testing"
 )
@@ -18,3 +19,7 @@ func TestWrapper(t *testing.T) {
 	l := With(MultiLogger(out, err), "ts", DefaultTimestamp, "caller", DefaultCaller)
 	_ = l.Log(LevelInfo, "msg", "test")
 }
+
+func TestWithContext(t *testing.T) {
+	WithContext(context.Background(), nil)
+}
diff --git a/log/std_test.go b/log/std_test.go
index 0f11fe2f9..e9da7730a 100644
--- a/log/std_test.go
+++ b/log/std_test.go
@@ -10,4 +10,8 @@ func TestStdLogger(t *testing.T) {
 	_ = logger.Log(LevelInfo, "msg", "test info")
 	_ = logger.Log(LevelInfo, "msg", "test warn")
 	_ = logger.Log(LevelInfo, "msg", "test error")
+	_ = logger.Log(LevelDebug, "singular")
+
+	logger2 := DefaultLogger
+	_ = logger2.Log(LevelDebug)
 }
diff --git a/log/value_test.go b/log/value_test.go
index adc3ed9b9..fd9167a69 100644
--- a/log/value_test.go
+++ b/log/value_test.go
@@ -1,9 +1,30 @@
 package log
 
-import "testing"
+import (
+	"context"
+	"testing"
+)
 
 func TestValue(t *testing.T) {
 	logger := DefaultLogger
 	logger = With(logger, "ts", DefaultTimestamp, "caller", DefaultCaller)
 	_ = logger.Log(LevelInfo, "msg", "helloworld")
+
+	logger = DefaultLogger
+	logger = With(logger)
+	_ = logger.Log(LevelDebug, "msg", "helloworld")
+
+	var v1 interface{}
+	got := Value(context.Background(), v1)
+	if got != v1 {
+		t.Errorf("Value() = %v, want %v", got, v1)
+	}
+	var v2 Valuer = func(ctx context.Context) interface{} {
+		return 3
+	}
+	got = Value(context.Background(), v2)
+	res := got.(int)
+	if res != 3 {
+		t.Errorf("Value() = %v, want %v", res, 3)
+	}
 }