Address reviewer comments

Signed-off-by: Per Goncalves da Silva <[email protected]>

internal/catalogmetadata/filter/successors_test.go

@@ -1,6 +1,7 @@
 package filter
 
 import (
+	"github.com/operator-framework/operator-controller/internal/util/filter"
 	"slices"
 	"testing"
 
@@ -16,7 +17,6 @@ import (
 	ocv1 "github.com/operator-framework/operator-controller/api/v1"
 	"github.com/operator-framework/operator-controller/internal/bundleutil"
 	"github.com/operator-framework/operator-controller/internal/catalogmetadata/compare"
-	slicesutil "github.com/operator-framework/operator-controller/internal/util/slices"
 )
 
 func TestSuccessorsPredicate(t *testing.T) {
@@ -161,7 +161,7 @@ func TestSuccessorsPredicate(t *testing.T) {
 			for _, bundle := range bundleSet {
 				allBundles = append(allBundles, bundle)
 			}
-			result := slicesutil.RemoveInPlace(allBundles, successors)
+			result := filter.InPlace(allBundles, successors)
 
 			// sort before comparison for stable order
 			slices.SortFunc(result, compare.ByVersion)

internal/resolve/catalog.go

@@ -23,7 +23,6 @@ import (
 	"github.com/operator-framework/operator-controller/internal/catalogmetadata/compare"
 	"github.com/operator-framework/operator-controller/internal/catalogmetadata/filter"
 	filterutil "github.com/operator-framework/operator-controller/internal/util/filter"
-	slicesutil "github.com/operator-framework/operator-controller/internal/util/slices"
 )
 
 type ValidationFunc func(*declcfg.Bundle) error
@@ -120,7 +119,7 @@ func (r *CatalogResolver) Resolve(ctx context.Context, ext *ocv1.ClusterExtensio
 		}
 
 		// Apply the predicates to get the candidate bundles
-		packageFBC.Bundles = slicesutil.RemoveInPlace(packageFBC.Bundles, filterutil.And(predicates...))
+		packageFBC.Bundles = filterutil.InPlace(packageFBC.Bundles, filterutil.And(predicates...))
 		cs.MatchedBundles = len(packageFBC.Bundles)
 		if len(packageFBC.Bundles) == 0 {
 			return nil

internal/util/filter/predicates.go → internal/util/filter/filter.go

@@ -1,5 +1,7 @@
 package filter
 
+import "slices"
+
 // Predicate returns true if the object should be kept when filtering
 type Predicate[T any] func(entity T) bool
 
@@ -30,3 +32,20 @@ func Not[T any](predicate Predicate[T]) Predicate[T] {
 		return !predicate(obj)
 	}
 }
+
+// Filter creates a new slice with all elements from s for which the test returns true
+func Filter[T any](s []T, test Predicate[T]) []T {
+	var out []T
+	for i := 0; i < len(s); i++ {
+		if test(s[i]) {
+			out = append(out, s[i])
+		}
+	}
+	return slices.Clip(out)
+}
+
+// InPlace keeps all elements from s for which test returns true and removes all others.
+// Elements between new length and original length are zeroed out.
+func InPlace[T any](s []T, test Predicate[T]) []T {
+	return slices.DeleteFunc(s, Not(test))
+}

internal/util/filter/predicates_test.go → internal/util/filter/filter_test.go

@@ -145,3 +145,95 @@ func TestNot(t *testing.T) {
 		})
 	}
 }
+
+func TestFilter(t *testing.T) {
+	tests := []struct {
+		name      string
+		slice     []int
+		predicate filter.Predicate[int]
+		want      []int
+	}{
+		{
+			name:      "all match",
+			slice:     []int{1, 2, 3, 4, 5},
+			predicate: func(i int) bool { return i > 0 },
+			want:      []int{1, 2, 3, 4, 5},
+		},
+		{
+			name:      "some match",
+			slice:     []int{1, 2, 3, 4, 5},
+			predicate: func(i int) bool { return i > 3 },
+			want:      []int{4, 5},
+		},
+		{
+			name:      "none match",
+			slice:     []int{1, 2, 3, 4, 5},
+			predicate: func(i int) bool { return i > 5 },
+			want:      nil,
+		},
+		{
+			name:      "empty slice",
+			slice:     []int{},
+			predicate: func(i int) bool { return i > 5 },
+			want:      nil,
+		},
+		{
+			name:      "nil slice",
+			slice:     nil,
+			predicate: func(i int) bool { return i > 5 },
+			want:      nil,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := filter.Filter(tt.slice, tt.predicate)
+			require.Equal(t, tt.want, got, "Filter() = %v, want %v", got, tt.want)
+		})
+	}
+}
+
+func TestInPlace(t *testing.T) {
+	tests := []struct {
+		name      string
+		slice     []int
+		predicate filter.Predicate[int]
+		want      []int
+	}{
+		{
+			name:      "all match",
+			slice:     []int{1, 2, 3, 4, 5},
+			predicate: func(i int) bool { return i > 0 },
+			want:      []int{1, 2, 3, 4, 5},
+		},
+		{
+			name:      "some match",
+			slice:     []int{1, 2, 3, 4, 5},
+			predicate: func(i int) bool { return i > 3 },
+			want:      []int{4, 5},
+		},
+		{
+			name:      "none match",
+			slice:     []int{1, 2, 3, 4, 5},
+			predicate: func(i int) bool { return i > 5 },
+			want:      []int{},
+		},
+		{
+			name:      "empty slice",
+			slice:     []int{},
+			predicate: func(i int) bool { return i > 5 },
+			want:      []int{},
+		},
+		{
+			name:      "nil slice",
+			slice:     nil,
+			predicate: func(i int) bool { return i > 5 },
+			want:      nil,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := filter.InPlace(tt.slice, tt.predicate)
+			require.Equal(t, tt.want, got, "Filter() = %v, want %v", got, tt.want)
+		})
+	}
+}