Add unit tests for controller and fix linting

In this commit we also:
- Fix error handler in defer func
- Added assertions to unit test inside the controller
- - Trying to create assertions to onAdd
- - Add right assertions to onAdd
- - Add assertions to onDelete
- - Add assertions to onUpdate
- - tidy up
- - clean up
- - Add changes suggested by the review
- - Refactor to apply reflect.DeepEqual
- - Refactor to remove reflect.ValueOf
- - Refactor mock and add positive tc onDelete
- - Change got the variable scope

Author: togashidm

telemetry-aware-scheduling/pkg/cache/mocks.go

@@ -2,6 +2,7 @@ package cache
 
 //This file contains mock methods and objects which are used to test across the TAS packages.
 import (
+	"fmt"
 	"time"
 
 	"k8s.io/klog/v2"
@@ -12,6 +13,11 @@ import (
 	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
+// MockCache is used in the tests for the core and other packages.
+type MockCache struct {
+	MockCache interface{}
+}
+
 //MockEmptySelfUpdatingCache returns auto updating cache
 func MockEmptySelfUpdatingCache() ReaderWriter {
 	n := NewAutoUpdatingCache()
@@ -52,3 +58,49 @@ var mockPolicy = telemetrypolicy.TASPolicy{
 var mockPolicy2 = telemetrypolicy.TASPolicy{
 	ObjectMeta: v1.ObjectMeta{Name: "not-mock-policy", Namespace: "default"},
 }
+
+// ReadMetric is a method implemented for Mock cache.
+func (n MockCache) ReadMetric(string) (metrics.NodeMetricsInfo, error) {
+	return metrics.NodeMetricsInfo{}, nil
+}
+
+// ReadPolicy is a method implemented for Mock cache.
+func (n MockCache) ReadPolicy(string, string) (telemetrypolicy.TASPolicy, error) {
+	return telemetrypolicy.TASPolicy{}, nil
+}
+
+// WriteMetric is a method implemented for Mock cache.
+func (n MockCache) WriteMetric(metricName string, _ metrics.NodeMetricsInfo) error {
+	if metricName != "" {
+		return nil
+	}
+
+	return fmt.Errorf("failed to write metric")
+}
+
+// WritePolicy is a method implemented for Mock cache.
+func (n MockCache) WritePolicy(namespace string, _ string, _ telemetrypolicy.TASPolicy) error {
+	if namespace != "default" {
+		return fmt.Errorf("failed to write policy")
+	}
+
+	return nil
+}
+
+// DeleteMetric is a method implemented for Mock cache.
+func (n MockCache) DeleteMetric(metricName string) error {
+	if metricName != "" {
+		return nil
+	}
+
+	return fmt.Errorf("no metric to delete")
+}
+
+// DeletePolicy is a method implemented for Mock cache.
+func (n MockCache) DeletePolicy(namespace string, policyName string) error {
+	if namespace != "default" || policyName == "" {
+		return fmt.Errorf("failed to delete policy")
+	}
+
+	return nil
+}

telemetry-aware-scheduling/pkg/controller/controller.go

@@ -24,7 +24,8 @@ import (
 func (controller *TelemetryPolicyController) Run(context context.Context) {
 	log.Print("Watching Telemetry Policies", "component", "controller")
 	defer func() {
-		if err := recover(); err != nil {
+		err := recover()
+		if err != nil {
 			log.Print("Recovered from runtime error", "component", "controller")
 		}
 	}()
@@ -118,8 +119,7 @@ func (controller *TelemetryPolicyController) onUpdate(old, new interface{}) {
 	polCopy := newPol.DeepCopy()
 	err := controller.WritePolicy(polCopy.Namespace, polCopy.Name, *polCopy)
 	if err != nil {
-		msg := fmt.Sprintf("cached policy not updated %v", err)
-		klog.V(2).InfoS(msg, "component", "controller")
+		klog.V(2).InfoS(fmt.Sprintf("cached policy not updated %v", err), "component", "controller")
 		return
 	}
 	klog.V(2).InfoS("Policy: "+polCopy.Name+" updated", "component", "controller")