UT: Increase unit test coverage of pkg/bootstrap (#101)

Signed-off-by: charlie <qianglin98@qq.com>

pkg/bootstrap/server_test.go

@@ -0,0 +1,66 @@
+// Copyright (c) 2022 Alibaba Group Holding Ltd.
+//
+// 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 bootstrap
+
+import (
+	"context"
+	"testing"
+
+	"github.com/agiledragon/gomonkey/v2"
+	"istio.io/istio/pilot/pkg/features"
+	"istio.io/istio/pkg/keepalive"
+
+	higresskube "github.com/alibaba/higress/pkg/kube"
+)
+
+func TestStartWithNoError(t *testing.T) {
+	var (
+		s   *Server
+		err error
+	)
+
+	mockFn := func(s *Server) error {
+		s.kubeClient = higresskube.NewFakeClient()
+		return nil
+	}
+
+	gomonkey.ApplyFunc((*Server).initKubeClient, mockFn)
+
+	if s, err = NewServer(newServerArgs()); err != nil {
+		t.Errorf("failed to create server: %v", err)
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	if err = s.Start(ctx.Done()); err != nil {
+		t.Errorf("failed to start the server: %v", err)
+	}
+}
+
+func newServerArgs() *ServerArgs {
+	return &ServerArgs{
+		Debug:                true,
+		NativeIstio:          true,
+		HttpAddress:          ":8888",
+		GrpcAddress:          ":15051",
+		GrpcKeepAliveOptions: keepalive.DefaultOption(),
+		XdsOptions: XdsOptions{
+			DebounceAfter:     features.DebounceAfter,
+			DebounceMax:       features.DebounceMax,
+			EnableEDSDebounce: features.EnableEDSDebounce,
+		},
+	}
+}