Split plugin framework into its own package

Signed-off-by: Carlisia <carlisiac@vmware.com>

pkg/plugin/framework/client_dispenser_test.go

@@ -0,0 +1,81 @@
+/*
+Copyright 2018, 2019 the Velero contributors.
+
+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 framework
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"google.golang.org/grpc"
+
+	"github.com/heptio/velero/pkg/util/test"
+)
+
+type fakeClient struct {
+	base       *clientBase
+	clientConn *grpc.ClientConn
+}
+
+func TestNewClientDispenser(t *testing.T) {
+	logger := test.NewLogger()
+
+	clientConn := new(grpc.ClientConn)
+
+	c := 3
+	initFunc := func(base *clientBase, clientConn *grpc.ClientConn) interface{} {
+		return c
+	}
+
+	cd := newClientDispenser(logger, clientConn, initFunc)
+	assert.Equal(t, clientConn, cd.clientConn)
+	assert.NotNil(t, cd.clients)
+	assert.Empty(t, cd.clients)
+}
+
+func TestClientFor(t *testing.T) {
+	logger := test.NewLogger()
+	clientConn := new(grpc.ClientConn)
+
+	c := new(fakeClient)
+	count := 0
+	initFunc := func(base *clientBase, clientConn *grpc.ClientConn) interface{} {
+		c.base = base
+		c.clientConn = clientConn
+		count++
+		return c
+	}
+
+	cd := newClientDispenser(logger, clientConn, initFunc)
+
+	actual := cd.ClientFor("pod")
+	require.IsType(t, &fakeClient{}, actual)
+	typed := actual.(*fakeClient)
+	assert.Equal(t, 1, count)
+	assert.Equal(t, &typed, &c)
+	expectedBase := &clientBase{
+		plugin: "pod",
+		logger: logger,
+	}
+	assert.Equal(t, expectedBase, typed.base)
+	assert.Equal(t, clientConn, typed.clientConn)
+
+	// Make sure we reuse a previous client
+	actual = cd.ClientFor("pod")
+	require.IsType(t, &fakeClient{}, actual)
+	typed = actual.(*fakeClient)
+	assert.Equal(t, 1, count)
+}