dag: add RegexRoute test

Signed-off-by: Dave Cheney <dave@cheney.net>

internal/dag/builder_test.go

@@ -537,6 +537,28 @@ func TestDAGInsert(t *testing.T) {
 		},
 	}
 
+	i15 := &v1beta1.Ingress{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "regex",
+			Namespace: "default",
+		},
+		Spec: v1beta1.IngressSpec{
+			Rules: []v1beta1.IngressRule{{
+				IngressRuleValue: v1beta1.IngressRuleValue{
+					HTTP: &v1beta1.HTTPIngressRuleValue{
+						Paths: []v1beta1.HTTPIngressPath{{
+							Path: "/[^/]+/invoices(/.*|/?)", // issue 1243
+							Backend: v1beta1.IngressBackend{
+								ServiceName: "kuard",
+								ServicePort: intstr.FromString("http"),
+							},
+						}},
+					},
+				},
+			}},
+		},
+	}
+
 	// s3a and b have http/2 protocol annotations
 	s3a := &v1.Service{
 		ObjectMeta: metav1.ObjectMeta{
@@ -2566,6 +2588,25 @@ func TestDAGInsert(t *testing.T) {
 				},
 			),
 		},
+		"insert ingressroute with regex route": {
+			objs: []interface{}{
+				i15,
+				s1,
+			},
+			want: listeners(
+				&Listener{
+					Port: 80,
+					VirtualHosts: virtualhosts(
+						virtualhost("*", &RegexRoute{
+							Regex: "/[^/]+/invoices(/.*|/?)",
+							Route: Route{
+								Clusters: clustermap(s1),
+							},
+						}),
+					),
+				},
+			),
+		},
 		"insert ingress overlay": {
 			objs: []interface{}{
 				i13a, i13b, sec13, s13a, s13b,