add test

pkg/grpc/interceptor/tracing_test.go

@@ -0,0 +1,27 @@
+package interceptor
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestStreamClientTracing(t *testing.T) {
+	interceptor := StreamClientTracing()
+	assert.NotNil(t, interceptor)
+}
+
+func TestStreamServerTracing(t *testing.T) {
+	interceptor := StreamServerTracing()
+	assert.NotNil(t, interceptor)
+}
+
+func TestUnaryClientTracing(t *testing.T) {
+	interceptor := UnaryClientTracing()
+	assert.NotNil(t, interceptor)
+}
+
+func TestUnaryServerTracing(t *testing.T) {
+	interceptor := UnaryServerTracing()
+	assert.NotNil(t, interceptor)
+}