Add test for grpc memory plugin

plugin/storage/grpc/memory/plugin_test.go

@@ -0,0 +1,37 @@
+// Copyright (c) 2019 The Jaeger Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package memory
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/jaegertracing/jaeger/plugin/storage/memory"
+)
+
+func TestPluginUsesMemoryStorage(t *testing.T) {
+	mainStorage := memory.NewStore()
+	archiveStorage := memory.NewStore()
+
+	memStorePlugin := NewStoragePlugin(mainStorage, archiveStorage)
+
+	assert.Equal(t, mainStorage, memStorePlugin.DependencyReader())
+	assert.Equal(t, mainStorage, memStorePlugin.SpanReader())
+	assert.Equal(t, mainStorage, memStorePlugin.SpanWriter())
+	assert.Equal(t, archiveStorage, memStorePlugin.ArchiveSpanReader())
+	assert.Equal(t, archiveStorage, memStorePlugin.ArchiveSpanWriter())
+
+}