Reduce code duplication and fix typo (#4424)

* Reduce code duplication and fix typo

* fix apihandler.go

* fix

* fix

* use golint

if block ends with a return statement, so drop this else and outdent its block

* use golint

apihandler.go:1168:2: var sessionId should be sessionID

* fix a space

* fix

* fix

src/app/backend/api/types.go

@@ -141,6 +141,7 @@ const (
 	ResourceKindEndpoint                 = "endpoint"
 )
 
+// Scalable method return whether ResourceKind is scalable.
 func (k ResourceKind) Scalable() bool {
 	scalable := []ResourceKind{
 		ResourceKindDeployment,
@@ -177,6 +178,7 @@ const (
 	ClientTypePluginsClient       = "plugin"
 )
 
+// APIMapping is the mapping from resource kind to ClientType and Namespaced.
 type APIMapping struct {
 	// Kubernetes resource name.
 	Resource string
@@ -186,7 +188,7 @@ type APIMapping struct {
 	Namespaced bool
 }
 
-// Mapping from resource kind to K8s apiserver API path. This is mostly pluralization, because
+// KindToAPIMapping is the mapping from resource kind to K8s apiserver API path. This is mostly pluralization, because
 // Kubernetes apiserver uses plural paths and this project singular.
 // Must be kept in sync with the list of supported kinds.
 // See: https://kubernetes.io/docs/reference/
@@ -219,14 +221,14 @@ var KindToAPIMapping = map[string]APIMapping{
 }
 
 // IsSelectorMatching returns true when an object with the given selector targets the same
-// Resources (or subset) that the tested object with the given selector.
-func IsSelectorMatching(labelSelector map[string]string, testedObjectLabels map[string]string) bool {
+// Resources (or subset) that the target object with the given selector.
+func IsSelectorMatching(srcSelector map[string]string, targetObjectLabels map[string]string) bool {
 	// If service has no selectors, then assume it targets different resource.
-	if len(labelSelector) == 0 {
+	if len(srcSelector) == 0 {
 		return false
 	}
-	for label, value := range labelSelector {
-		if rsValue, ok := testedObjectLabels[label]; !ok || rsValue != value {
+	for label, value := range srcSelector {
+		if rsValue, ok := targetObjectLabels[label]; !ok || rsValue != value {
 			return false
 		}
 	}
@@ -234,18 +236,14 @@ func IsSelectorMatching(labelSelector map[string]string, testedObjectLabels map[
 }
 
 // IsLabelSelectorMatching returns true when a resource with the given selector targets the same
-// Resources(or subset) that a tested object selector with the given selector.
-func IsLabelSelectorMatching(selector map[string]string, labelSelector *v1.LabelSelector) bool {
-	// If the resource has no selectors, then assume it targets different Pods.
-	if len(selector) == 0 {
-		return false
-	}
-	for label, value := range selector {
-		if rsValue, ok := labelSelector.MatchLabels[label]; !ok || rsValue != value {
-			return false
-		}
+// Resources(or subset) that a target object selector with the given selector.
+func IsLabelSelectorMatching(srcSelector map[string]string, targetLabelSelector *v1.LabelSelector) bool {
+	// Check to see if targetLabelSelector pointer is not nil.
+	if targetLabelSelector != nil {
+		targetObjectLabels := targetLabelSelector.MatchLabels
+		return IsSelectorMatching(srcSelector, targetObjectLabels)
 	}
-	return true
+	return false
 }
 
 // ListEverything is a list options used to list all resources without any filtering.

src/app/backend/handler/apihandler.go

@@ -149,7 +149,7 @@ func CreateHTTPAPIHandler(iManager integration.IntegrationManager, cManager clie
 			Writes(validation.ProtocolValidity{}))
 	apiV1Ws.Route(
 		apiV1Ws.GET("/appdeployment/protocols").
-			To(apiHandler.handleGetAvailableProcotols).
+			To(apiHandler.handleGetAvailableProtocols).
 			Writes(deployment.Protocols{}))
 
 	apiV1Ws.Route(
@@ -939,12 +939,12 @@ func (apiHandler *APIHandler) handleGetReplicaCount(request *restful.Request, re
 	namespace := request.PathParameter("namespace")
 	kind := request.PathParameter("kind")
 	name := request.PathParameter("name")
-	scaleSpec, err := scaling.GetScaleSpec(cfg, kind, namespace, name)
+	replicaCounts, err := scaling.GetReplicaCounts(cfg, kind, namespace, name)
 	if err != nil {
 		errors.HandleInternalError(response, err)
 		return
 	}
-	response.WriteHeaderAndEntity(http.StatusOK, scaleSpec)
+	response.WriteHeaderAndEntity(http.StatusOK, replicaCounts)
 }
 
 func (apiHandler *APIHandler) handleDeployFromFile(request *restful.Request, response *restful.Response) {
@@ -1024,7 +1024,7 @@ func (apiHandler *APIHandler) handleProtocolValidity(request *restful.Request, r
 	response.WriteHeaderAndEntity(http.StatusOK, validation.ValidateProtocol(spec))
 }
 
-func (apiHandler *APIHandler) handleGetAvailableProcotols(request *restful.Request, response *restful.Response) {
+func (apiHandler *APIHandler) handleGetAvailableProtocols(request *restful.Request, response *restful.Response) {
 	response.WriteHeaderAndEntity(http.StatusOK, deployment.GetAvailableProtocols())
 }
 
@@ -1165,7 +1165,7 @@ func (apiHandler *APIHandler) handleGetPodEvents(request *restful.Request, respo
 
 // Handles execute shell API call
 func (apiHandler *APIHandler) handleExecShell(request *restful.Request, response *restful.Response) {
-	sessionId, err := genTerminalSessionId()
+	sessionID, err := genTerminalSessionId()
 	if err != nil {
 		errors.HandleInternalError(response, err)
 		return
@@ -1183,13 +1183,13 @@ func (apiHandler *APIHandler) handleExecShell(request *restful.Request, response
 		return
 	}
 
-	terminalSessions.Set(sessionId, TerminalSession{
-		id:       sessionId,
+	terminalSessions.Set(sessionID, TerminalSession{
+		id:       sessionID,
 		bound:    make(chan error),
 		sizeChan: make(chan remotecommand.TerminalSize),
 	})
-	go WaitForTerminal(k8sClient, cfg, request, sessionId)
-	response.WriteHeaderAndEntity(http.StatusOK, TerminalResponse{Id: sessionId})
+	go WaitForTerminal(k8sClient, cfg, request, sessionID)
+	response.WriteHeaderAndEntity(http.StatusOK, TerminalResponse{Id: sessionID})
 }
 
 func (apiHandler *APIHandler) handleGetDeployments(request *restful.Request, response *restful.Response) {

src/app/backend/scaling/scale.go

@@ -34,8 +34,8 @@ type ReplicaCounts struct {
 	ActualReplicas  int32 `json:"actualReplicas"`
 }
 
-// GetScaleSpec returns a populated ReplicaCounts object with desired and actual number of replicas.
-func GetScaleSpec(cfg *rest.Config, kind, namespace, name string) (*ReplicaCounts, error) {
+// GetReplicaCounts returns a populated ReplicaCounts object with desired and actual number of replicas.
+func GetReplicaCounts(cfg *rest.Config, kind, namespace, name string) (*ReplicaCounts, error) {
 	sc, err := getScaleGetter(cfg)
 	if err != nil {
 		return nil, err
@@ -116,7 +116,7 @@ func getGroupResource(kind string) schema.GroupResource {
 
 	if gr.Group != "" && gr.Resource != "" {
 		return gr
-	} else {
-		return apps.Resource(kind)
 	}
+
+	return apps.Resource(kind)
 }