Add Additional API Testing for GEP-3171 (#3302)

* Make HTTPRequestMirrorFilter's fraction field a pointer

* Update and rename grcproute_experimental_test.go to grpcroute_experimental_test.go

* Add more tests to TestHTTPRequestMirrorFilterExperimental

* Ran hack/update-codegen.sh

* Fix typo

* Fix typo in httproute_experimental_test.go

* Fix boilerplate header for grpcroute_experimental_test.go

apis/v1/httproute_types.go

@@ -1177,7 +1177,7 @@ type HTTPRequestMirrorFilter struct {
 	//
 	// +optional
 	// <gateway:experimental>
-	Fraction Fraction `json:"fraction,omitempty"`
+	Fraction *Fraction `json:"fraction,omitempty"`
 }
 
 // HTTPBackendRef defines how a HTTPRoute forwards a HTTP request.

pkg/test/cel/grpcroute_experimental_test.go

@@ -0,0 +1,181 @@
+//go:build experimental
+// +build experimental
+
+/*
+Copyright 2024 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	gatewayv1 "sigs.k8s.io/gateway-api/apis/v1"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+//
+// How are tests named? Where to add new tests?
+//
+// Ensure that tests for newly added CEL validations are added in the correctly
+// named test function. For example, if you added a test at the
+// `GRPCRouteFilter` hierarchy (i.e. either at the struct level, or on one of
+// the immediate descendent fields), then the test will go in the
+// TestGRPCRouteFilter function. If the appropriate test function does not
+// exist, please create one.
+//
+////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+
+func TestGRPCRequestMirrorFilterExperimental(t *testing.T) {
+	var percent int32 = 42
+	var denominator int32 = 1000
+	var bad_denominator int32 = 0
+	testService := gatewayv1.ObjectName("test-service")
+	tests := []struct {
+		name       string
+		wantErrors []string
+		rules      []gatewayv1.GRPCRouteRule
+	}{
+		{
+			name: "GRPCRoute - Invalid because both percent and fraction are specified",
+			wantErrors: []string{"Only one of percent or fraction may be specified in HTTPRequestMirrorFilter"},
+			rules: []gatewayv1.GRPCRouteRule{{
+				Filters: []gatewayv1.GRPCRouteFilter{{
+					Type: gatewayv1.GRPCRouteFilterRequestMirror,
+					RequestMirror: &gatewayv1.HTTPRequestMirrorFilter{
+						BackendRef: gatewayv1.BackendObjectReference{
+							Name: testService,
+							Port: ptrTo(gatewayv1.PortNumber(8081)),
+						},
+						Percent: &percent,
+						Fraction: &gatewayv1.Fraction{
+							Numerator: 83,
+							Denominator: &denominator,
+						},
+					},
+				}},
+			}},
+		},
+		{
+			name: "GRPCRoute - Invalid fraction - numerator greater than denominator",
+			wantErrors: []string{"numerator must be less than or equal to denominator"},
+			rules: []gatewayv1.GRPCRouteRule{{
+				Filters: []gatewayv1.GRPCRouteFilter{{
+					Type: gatewayv1.GRPCRouteFilterRequestMirror,
+					RequestMirror: &gatewayv1.HTTPRequestMirrorFilter{
+						BackendRef: gatewayv1.BackendObjectReference{
+							Name: testService,
+							Port: ptrTo(gatewayv1.PortNumber(8081)),
+						},
+						Fraction: &gatewayv1.Fraction{
+							Numerator: 1001,
+							Denominator: &denominator,
+						},
+					},
+				}},
+			}},
+		},
+		{
+			name: "GRPCRoute - Invalid fraction - denominator is 0",
+			wantErrors: []string{"spec.rules[0].filters[0].requestMirror.fraction.denominator in body should be greater than or equal to 1"},
+			rules: []gatewayv1.GRPCRouteRule{{
+				Filters: []gatewayv1.GRPCRouteFilter{{
+					Type: gatewayv1.GRPCRouteFilterRequestMirror,
+					RequestMirror: &gatewayv1.HTTPRequestMirrorFilter{
+						BackendRef: gatewayv1.BackendObjectReference{
+							Name: testService,
+							Port: ptrTo(gatewayv1.PortNumber(8081)),
+						},
+						Fraction: &gatewayv1.Fraction{
+							Numerator: 0,
+							Denominator: &bad_denominator,
+						},
+					},
+				}},
+			}},
+		},
+		{
+			name: "GRPCRoute - Invalid fraction - numerator is negative",
+			wantErrors: []string{"spec.rules[0].filters[0].requestMirror.fraction.numerator in body should be greater than or equal to 0"},
+			rules: []gatewayv1.GRPCRouteRule{{
+				Filters: []gatewayv1.GRPCRouteFilter{{
+					Type: gatewayv1.GRPCRouteFilterRequestMirror,
+					RequestMirror: &gatewayv1.HTTPRequestMirrorFilter{
+						BackendRef: gatewayv1.BackendObjectReference{
+							Name: testService,
+							Port: ptrTo(gatewayv1.PortNumber(8081)),
+						},
+						Fraction: &gatewayv1.Fraction{
+							Numerator: -1,
+							Denominator: &denominator,
+						},
+					},
+				}},
+			}},
+		},
+		{
+			name: "GRPCRoute - Valid with percent",
+			rules: []gatewayv1.GRPCRouteRule{{
+				Filters: []gatewayv1.GRPCRouteFilter{{
+					Type: gatewayv1.GRPCRouteFilterRequestMirror,
+					RequestMirror: &gatewayv1.HTTPRequestMirrorFilter{
+						BackendRef: gatewayv1.BackendObjectReference{
+							Name: testService,
+							Port: ptrTo(gatewayv1.PortNumber(8081)),
+						},
+						Percent: &percent,
+					},
+				}},
+			}},
+		},
+		{
+			name: "GRPCRoute - Valid with fraction",
+			rules: []gatewayv1.GRPCRouteRule{{
+				Filters: []gatewayv1.GRPCRouteFilter{{
+					Type: gatewayv1.GRPCRouteFilterRequestMirror,
+					RequestMirror: &gatewayv1.HTTPRequestMirrorFilter{
+						BackendRef: gatewayv1.BackendObjectReference{
+							Name: testService,
+							Port: ptrTo(gatewayv1.PortNumber(8081)),
+						},
+						Fraction: &gatewayv1.Fraction{
+							Numerator: 83,
+							Denominator: &denominator,
+						},
+					},
+				}},
+			}},
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			route := &gatewayv1.GRPCRoute{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      fmt.Sprintf("foo-%v", time.Now().UnixNano()),
+					Namespace: metav1.NamespaceDefault,
+				},
+				Spec: gatewayv1.GRPCRouteSpec{Rules: tc.rules},
+			}
+			validateGRPCRoute(t, route, tc.wantErrors)
+		})
+	}
+}