Add test coverage of result size of string operations

staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/validation/validation_test.go

@@ -9315,6 +9315,32 @@ func TestValidateCustomResourceDefinitionValidation(t *testing.T) {
 				forbidden("spec.validation.openAPIV3Schema.properties[f].x-kubernetes-validations[0].messageExpression"),
 			},
 		},
+		{
+			name: "x-kubernetes-validations rule with lowerAscii check should be within estimated cost limit",
+			opts: validationOptions{requireStructuralSchema: true},
+			input: apiextensions.CustomResourceValidation{
+				OpenAPIV3Schema: &apiextensions.JSONSchemaProps{
+					Type: "object",
+					Properties: map[string]apiextensions.JSONSchemaProps{
+						"f": {
+							Type:     "array",
+							MaxItems: pointer.Int64(5),
+							Items: &apiextensions.JSONSchemaPropsOrArray{
+								Schema: &apiextensions.JSONSchemaProps{
+									Type:      "string",
+									MaxLength: pointer.Int64(5),
+								},
+							},
+							XValidations: apiextensions.ValidationRules{
+								{
+									Rule: "self.all(x, self.exists_one(y, x.lowerAscii() == y.lowerAscii()))",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
 		{
 			name: "x-kubernetes-validations rule invalidated by messageExpression exceeding per-CRD estimated cost limit",
 			opts: validationOptions{requireStructuralSchema: true},

staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/cel/celcoststability_test.go

@@ -115,6 +115,7 @@ func TestCelCostStability(t *testing.T) {
 				"self.val1.substring(4, 10).trim() == 'takes'":     6,
 				"self.val1.upperAscii() == 'ROOK TAKES 👑'":         6,
 				"self.val1.lowerAscii() == 'rook takes 👑'":         6,
+				"self.val1.lowerAscii() == self.val1.lowerAscii()": 10,
 			},
 		},
 		{name: "escaped strings",

staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/cel/compilation_test.go

@@ -1691,9 +1691,9 @@ func TestCostEstimation(t *testing.T) {
 				objType = withRule(objType, "self.str.replace(self.before, self.after) == 'does not matter'")
 				return &objType
 			},
-			expectedCalcCost: 629154,
+			expectedCalcCost: 629152, // cost is based on the result size of the replace() call
 			setMaxElements:   10,
-			expectedSetCost:  16,
+			expectedSetCost:  14,
 		},
 		{
 			name: "extended library split",

staging/src/k8s.io/apiserver/pkg/cel/library/cost_test.go

@@ -227,12 +227,36 @@ func TestStringLibrary(t *testing.T) {
 			expectEsimatedCost: checker.CostEstimate{Min: 3, Max: 3},
 			expectRuntimeCost:  3,
 		},
+		{
+			name:               "lowerAsciiEquals",
+			expr:               "'ABCDEFGHIJ abcdefghij'.lowerAscii() == 'abcdefghij ABCDEFGHIJ'.lowerAscii()",
+			expectEsimatedCost: checker.CostEstimate{Min: 7, Max: 9},
+			expectRuntimeCost:  9,
+		},
 		{
 			name:               "upperAscii",
 			expr:               "'ABCDEFGHIJ abcdefghij'.upperAscii()",
 			expectEsimatedCost: checker.CostEstimate{Min: 3, Max: 3},
 			expectRuntimeCost:  3,
 		},
+		{
+			name:               "upperAsciiEquals",
+			expr:               "'ABCDEFGHIJ abcdefghij'.upperAscii() == 'abcdefghij ABCDEFGHIJ'.upperAscii()",
+			expectEsimatedCost: checker.CostEstimate{Min: 7, Max: 9},
+			expectRuntimeCost:  9,
+		},
+		{
+			name:               "quote",
+			expr:               "strings.quote('ABCDEFGHIJ abcdefghij')",
+			expectEsimatedCost: checker.CostEstimate{Min: 3, Max: 3},
+			expectRuntimeCost:  3,
+		},
+		{
+			name:               "quoteEquals",
+			expr:               "strings.quote('ABCDEFGHIJ abcdefghij') == strings.quote('ABCDEFGHIJ abcdefghij')",
+			expectEsimatedCost: checker.CostEstimate{Min: 7, Max: 11},
+			expectRuntimeCost:  9,
+		},
 		{
 			name:               "replace",
 			expr:               "'abc 123 def 123'.replace('123', '456')",