feat: Add SMTPSession and BeforeRcptToAccepted event (#541)

Signed-off-by: James Hillyerd <james@hillyerd.com>

pkg/extension/luahost/bind_smtpsession_test.go

@@ -0,0 +1,38 @@
+package luahost
+
+import (
+	"net/mail"
+	"testing"
+
+	"github.com/inbucket/inbucket/v3/pkg/extension/event"
+	"github.com/inbucket/inbucket/v3/pkg/test"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSMTPSessionGetters(t *testing.T) {
+	want := &event.SMTPSession{
+		From: &mail.Address{Name: "name1", Address: "addr1"},
+		To: []*mail.Address{
+			{Name: "name2", Address: "addr2"},
+			{Name: "name3", Address: "addr3"},
+		},
+	}
+	script := `
+		assert(msg, "msg should not be nil")
+
+		assert_eq(msg.from.name, "name1", "from.name")
+		assert_eq(msg.from.address, "addr1", "from.address")
+
+		assert_eq(#msg.to, 2, "#msg.to")
+		assert_eq(msg.to[1].name, "name2", "to[1].name")
+		assert_eq(msg.to[1].address, "addr2", "to[1].address")
+		assert_eq(msg.to[2].name, "name3", "to[2].name")
+		assert_eq(msg.to[2].address, "addr3", "to[2].address")
+	`
+
+	ls, _ := test.NewLuaState()
+	registerSMTPSessionType(ls)
+	registerMailAddressType(ls)
+	ls.SetGlobal("msg", wrapSMTPSession(ls, want))
+	require.NoError(t, ls.DoString(script))
+}