Merge pull request kubernetes#40404 from tanshanshan/unit-test-scheduler4

Automatic merge from submit-queue (batch tested with PRs 40404, 43134, 43117)

Improve code coverage for scheduler/api/validation

**What this PR does / why we need it**:

Improve code coverage for scheduler/api/validation from kubernetes#39559

Thanks
**Special notes for your reviewer**:

**Release note**:

```release-note
```

Author: Kubernetes Submit Queue

hack/.linted_packages

@@ -286,6 +286,7 @@ plugin/pkg/auth
 plugin/pkg/auth/authenticator/token/bootstrap
 plugin/pkg/auth/authorizer
 plugin/pkg/auth/authorizer/rbac/bootstrappolicy
+plugin/pkg/scheduler/api/validation
 staging/src/k8s.io/apimachinery/pkg/api/equality
 staging/src/k8s.io/apimachinery/pkg/api/errors
 staging/src/k8s.io/apimachinery/pkg/api/resource

plugin/pkg/scheduler/api/validation/validation.go

@@ -23,10 +23,10 @@ import (
 	schedulerapi "k8s.io/kubernetes/plugin/pkg/scheduler/api"
 )
 
-// Validate checks for errors in the Config
+// ValidatePolicy checks for errors in the Config
 // It does not return early so that it can find as many errors as possible
 func ValidatePolicy(policy schedulerapi.Policy) error {
-	validationErrors := make([]error, 0)
+	var validationErrors []error
 
 	for _, priority := range policy.Priorities {
 		if priority.Weight <= 0 {

plugin/pkg/scheduler/api/validation/validation_test.go

@@ -50,3 +50,18 @@ func TestValidatePriorityWithNegativeWeight(t *testing.T) {
 		t.Errorf("Expected error about priority weight not being positive")
 	}
 }
+
+func TestValidateExtenderWithNonNegativeWeight(t *testing.T) {
+	extenderPolicy := api.Policy{ExtenderConfigs: []api.ExtenderConfig{{URLPrefix: "http://127.0.0.1:8081/extender", FilterVerb: "filter", Weight: 2}}}
+	errs := ValidatePolicy(extenderPolicy)
+	if errs != nil {
+		t.Errorf("Unexpected errors %v", errs)
+	}
+}
+
+func TestValidateExtenderWithNegativeWeight(t *testing.T) {
+	extenderPolicy := api.Policy{ExtenderConfigs: []api.ExtenderConfig{{URLPrefix: "http://127.0.0.1:8081/extender", FilterVerb: "filter", Weight: -2}}}
+	if ValidatePolicy(extenderPolicy) == nil {
+		t.Errorf("Expected error about priority weight for extender not being positive")
+	}
+}