API Machinery: Add equal func for Requirement struct

staging/src/k8s.io/apimachinery/pkg/labels/BUILD

@@ -37,6 +37,7 @@ go_library(
         "//staging/src/k8s.io/apimachinery/pkg/util/sets:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/validation:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/validation/field:go_default_library",
+        "//vendor/github.com/google/go-cmp/cmp:go_default_library",
         "//vendor/k8s.io/klog/v2:go_default_library",
     ],
 )

staging/src/k8s.io/apimachinery/pkg/labels/selector.go

@@ -22,6 +22,7 @@ import (
 	"strconv"
 	"strings"
 
+	"github.com/google/go-cmp/cmp"
 	"k8s.io/apimachinery/pkg/selection"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/apimachinery/pkg/util/validation"
@@ -276,6 +277,17 @@ func (r *Requirement) Values() sets.String {
 	return ret
 }
 
+// Equal checks the equality of requirement.
+func (r Requirement) Equal(x Requirement) bool {
+	if r.key != x.key {
+		return false
+	}
+	if r.operator != x.operator {
+		return false
+	}
+	return cmp.Equal(r.strValues, x.strValues)
+}
+
 // Empty returns true if the internalSelector doesn't restrict selection space
 func (s internalSelector) Empty() bool {
 	if s == nil {

staging/src/k8s.io/apimachinery/pkg/labels/selector_test.go

@@ -904,7 +904,7 @@ func TestValidatedSelectorFromSet(t *testing.T) {
 			t.Errorf("ValidatedSelectorFromSet %#v returned unexpected error (-want,+got):\n%s", tc.name, diff)
 		}
 		if err == nil {
-			if diff := cmp.Diff(tc.expectedSelector, selector, cmp.AllowUnexported(Requirement{})); diff != "" {
+			if diff := cmp.Diff(tc.expectedSelector, selector); diff != "" {
 				t.Errorf("ValidatedSelectorFromSet %#v returned unexpected selector (-want,+got):\n%s", tc.name, diff)
 			}
 		}
@@ -928,3 +928,75 @@ func BenchmarkRequirementString(b *testing.B) {
 		}
 	}
 }
+
+func TestRequirementEqual(t *testing.T) {
+	tests := []struct {
+		name string
+		x, y *Requirement
+		want bool
+	}{
+		{
+			name: "same requirements should be equal",
+			x: &Requirement{
+				key:       "key",
+				operator:  selection.Equals,
+				strValues: []string{"foo", "bar"},
+			},
+			y: &Requirement{
+				key:       "key",
+				operator:  selection.Equals,
+				strValues: []string{"foo", "bar"},
+			},
+			want: true,
+		},
+		{
+			name: "requirements with different keys should not be equal",
+			x: &Requirement{
+				key:       "key1",
+				operator:  selection.Equals,
+				strValues: []string{"foo", "bar"},
+			},
+			y: &Requirement{
+				key:       "key2",
+				operator:  selection.Equals,
+				strValues: []string{"foo", "bar"},
+			},
+			want: false,
+		},
+		{
+			name: "requirements with different operators should not be equal",
+			x: &Requirement{
+				key:       "key",
+				operator:  selection.Equals,
+				strValues: []string{"foo", "bar"},
+			},
+			y: &Requirement{
+				key:       "key",
+				operator:  selection.In,
+				strValues: []string{"foo", "bar"},
+			},
+			want: false,
+		},
+		{
+			name: "requirements with different values should not be equal",
+			x: &Requirement{
+				key:       "key",
+				operator:  selection.Equals,
+				strValues: []string{"foo", "bar"},
+			},
+			y: &Requirement{
+				key:       "key",
+				operator:  selection.Equals,
+				strValues: []string{"foobar"},
+			},
+			want: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := cmp.Equal(tt.x, tt.y); got != tt.want {
+				t.Errorf("cmp.Equal() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}