Fix route attachments to gateways

Co-authored-by: Romain <rtribotte@users.noreply.github.com>

pkg/provider/kubernetes/gateway/tlsroute_test.go

@@ -0,0 +1,66 @@
+package gateway
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	gatev1 "sigs.k8s.io/gateway-api/apis/v1"
+)
+
+func Test_hostSNIRule(t *testing.T) {
+	testCases := []struct {
+		desc         string
+		hostnames    []gatev1.Hostname
+		expectedRule string
+		expectError  bool
+	}{
+		{
+			desc:         "Empty",
+			expectedRule: "HostSNI(`*`)",
+		},
+		{
+			desc:         "Empty hostname",
+			hostnames:    []gatev1.Hostname{""},
+			expectedRule: "HostSNI(`*`)",
+		},
+		{
+			desc:         "Supported wildcard",
+			hostnames:    []gatev1.Hostname{"*.foo"},
+			expectedRule: "HostSNIRegexp(`^[a-z0-9-\\.]+\\.foo$`)",
+		},
+		{
+			desc:         "Some empty hostnames",
+			hostnames:    []gatev1.Hostname{"foo", "", "bar"},
+			expectedRule: "HostSNI(`foo`) || HostSNI(`bar`)",
+		},
+		{
+			desc:         "Valid hostname",
+			hostnames:    []gatev1.Hostname{"foo"},
+			expectedRule: "HostSNI(`foo`)",
+		},
+		{
+			desc:         "Multiple valid hostnames",
+			hostnames:    []gatev1.Hostname{"foo", "bar"},
+			expectedRule: "HostSNI(`foo`) || HostSNI(`bar`)",
+		},
+		{
+			desc:         "Multiple valid hostnames with wildcard",
+			hostnames:    []gatev1.Hostname{"bar.foo", "foo.foo", "*.foo"},
+			expectedRule: "HostSNI(`bar.foo`) || HostSNI(`foo.foo`) || HostSNIRegexp(`^[a-z0-9-\\.]+\\.foo$`)",
+		},
+		{
+			desc:         "Multiple overlapping hostnames",
+			hostnames:    []gatev1.Hostname{"foo", "bar", "foo", "baz"},
+			expectedRule: "HostSNI(`foo`) || HostSNI(`bar`) || HostSNI(`baz`)",
+		},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			rule := hostSNIRule(test.hostnames)
+			assert.Equal(t, test.expectedRule, rule)
+		})
+	}
+}