chore: remove unused parameter from util funcs; add unit test

Added the unit tests from
https://github.com/kubernetes/kubernetes/blob/master/pkg/util/slice/slice_test.go
(minus modifier tests) so we can be sure to not change behaviour.

pkg/utils/util.go

@@ -109,30 +109,23 @@ var SnapshotterListSecretParams = secretParamsMap{
 }
 
 // ContainsString checks if a given slice of strings contains the provided string.
-// If a modifier func is provided, it is called with the slice item before the comparation.
-func ContainsString(slice []string, s string, modifier func(s string) string) bool {
+func ContainsString(slice []string, s string) bool {
 	for _, item := range slice {
 		if item == s {
 			return true
 		}
-		if modifier != nil && modifier(item) == s {
-			return true
-		}
 	}
 	return false
 }
 
 // RemoveString returns a newly created []string that contains all items from slice that
-// are not equal to s and modifier(s) in case modifier func is provided.
-func RemoveString(slice []string, s string, modifier func(s string) string) []string {
+// are not equal to s.
+func RemoveString(slice []string, s string) []string {
 	newSlice := make([]string, 0)
 	for _, item := range slice {
 		if item == s {
 			continue
 		}
-		if modifier != nil && modifier(item) == s {
-			continue
-		}
 		newSlice = append(newSlice, item)
 	}
 	if len(newSlice) == 0 {
@@ -371,23 +364,23 @@ func NoResyncPeriodFunc() time.Duration {
 
 // NeedToAddContentFinalizer checks if a Finalizer needs to be added for the volume snapshot content.
 func NeedToAddContentFinalizer(content *crdv1.VolumeSnapshotContent) bool {
-	return content.ObjectMeta.DeletionTimestamp == nil && !ContainsString(content.ObjectMeta.Finalizers, VolumeSnapshotContentFinalizer, nil)
+	return content.ObjectMeta.DeletionTimestamp == nil && !ContainsString(content.ObjectMeta.Finalizers, VolumeSnapshotContentFinalizer)
 }
 
 // IsSnapshotDeletionCandidate checks if a volume snapshot deletionTimestamp
 // is set and any finalizer is on the snapshot.
 func IsSnapshotDeletionCandidate(snapshot *crdv1.VolumeSnapshot) bool {
-	return snapshot.ObjectMeta.DeletionTimestamp != nil && (ContainsString(snapshot.ObjectMeta.Finalizers, VolumeSnapshotAsSourceFinalizer, nil) || ContainsString(snapshot.ObjectMeta.Finalizers, VolumeSnapshotBoundFinalizer, nil))
+	return snapshot.ObjectMeta.DeletionTimestamp != nil && (ContainsString(snapshot.ObjectMeta.Finalizers, VolumeSnapshotAsSourceFinalizer) || ContainsString(snapshot.ObjectMeta.Finalizers, VolumeSnapshotBoundFinalizer))
 }
 
 // NeedToAddSnapshotAsSourceFinalizer checks if a Finalizer needs to be added for the volume snapshot as a source for PVC.
 func NeedToAddSnapshotAsSourceFinalizer(snapshot *crdv1.VolumeSnapshot) bool {
-	return snapshot.ObjectMeta.DeletionTimestamp == nil && !ContainsString(snapshot.ObjectMeta.Finalizers, VolumeSnapshotAsSourceFinalizer, nil)
+	return snapshot.ObjectMeta.DeletionTimestamp == nil && !ContainsString(snapshot.ObjectMeta.Finalizers, VolumeSnapshotAsSourceFinalizer)
 }
 
 // NeedToAddSnapshotBoundFinalizer checks if a Finalizer needs to be added for the bound volume snapshot.
 func NeedToAddSnapshotBoundFinalizer(snapshot *crdv1.VolumeSnapshot) bool {
-	return snapshot.ObjectMeta.DeletionTimestamp == nil && !ContainsString(snapshot.ObjectMeta.Finalizers, VolumeSnapshotBoundFinalizer, nil) && IsBoundVolumeSnapshotContentNameSet(snapshot)
+	return snapshot.ObjectMeta.DeletionTimestamp == nil && !ContainsString(snapshot.ObjectMeta.Finalizers, VolumeSnapshotBoundFinalizer) && IsBoundVolumeSnapshotContentNameSet(snapshot)
 }
 
 func deprecationWarning(deprecatedParam, newParam, removalVersion string) string {

pkg/utils/util_test.go

@@ -25,6 +25,58 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
+func TestContainsString(t *testing.T) {
+	src := []string{"aa", "bb", "cc"}
+	if !ContainsString(src, "bb") {
+		t.Errorf("ContainsString didn't find the string as expected")
+	}
+}
+
+func TestRemoveString(t *testing.T) {
+	tests := []struct {
+		testName string
+		input    []string
+		remove   string
+		want     []string
+	}{
+		{
+			testName: "Nil input slice",
+			input:    nil,
+			remove:   "",
+			want:     nil,
+		},
+		{
+			testName: "Slice doesn't contain the string",
+			input:    []string{"a", "ab", "cdef"},
+			remove:   "NotPresentInSlice",
+			want:     []string{"a", "ab", "cdef"},
+		},
+		{
+			testName: "All strings removed, result is nil",
+			input:    []string{"a"},
+			remove:   "a",
+			want:     nil,
+		},
+		{
+			testName: "One string removed",
+			input:    []string{"a", "ab", "cdef"},
+			remove:   "ab",
+			want:     []string{"a", "cdef"},
+		},
+		{
+			testName: "All(three) strings removed",
+			input:    []string{"ab", "a", "ab", "cdef", "ab"},
+			remove:   "ab",
+			want:     []string{"a", "cdef"},
+		},
+	}
+	for _, tt := range tests {
+		if got := RemoveString(tt.input, tt.remove); !reflect.DeepEqual(got, tt.want) {
+			t.Errorf("%v: RemoveString(%v, %q) = %v WANT %v", tt.testName, tt.input, tt.remove, got, tt.want)
+		}
+	}
+}
+
 func TestGetSecretReference(t *testing.T) {
 	testcases := map[string]struct {
 		secretParams    secretParamsMap