test: add more tests (#1147)

* test: add more tests

* test: add more tests

core/trace/attributes_test.go

@@ -0,0 +1,12 @@
+package trace
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	gcodes "google.golang.org/grpc/codes"
+)
+
+func TestStatusCodeAttr(t *testing.T) {
+	assert.Equal(t, GRPCStatusCodeKey.Int(int(gcodes.DataLoss)), StatusCodeAttr(gcodes.DataLoss))
+}