add more tests

rpcx/internal/rpcserver_test.go

@@ -0,0 +1,16 @@
+package internal
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/tal-tech/go-zero/core/stat"
+)
+
+func TestWithMetrics(t *testing.T) {
+	metrics := stat.NewMetrics("foo")
+	opt := WithMetrics(metrics)
+	var options rpcServerOptions
+	opt(&options)
+	assert.Equal(t, metrics, options.metrics)
+}