lua: bind BeforeMessageStored function (#418)

* lua: Restore missing test log output
* lua: Use logger for test assert_async output
* lua: add InboundMessage bindings
* lua: bind BeforeMessageStored function

---------

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

pkg/extension/luahost/bind_inboundmessage_test.go

@@ -0,0 +1,93 @@
+package luahost
+
+import (
+	"net/mail"
+	"testing"
+
+	"github.com/inbucket/inbucket/v3/pkg/extension/event"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	lua "github.com/yuin/gopher-lua"
+)
+
+// LuaInit holds useful test globals.
+const LuaInit = `
+	function assert_eq(got, want)
+		if type(got) == "table" and type(want) == "table" then
+			assert(#got == #want, string.format("got %d element(s), wanted %d", #got, #want))
+
+			for i, gotv in ipairs(got) do
+				local wantv = want[i]
+				assert_eq(gotv, wantv, "got[%d] = %q, wanted %q", gotv, wantv)
+			end
+
+			return
+		end
+
+		assert(got == want, string.format("got %q, wanted %q", got, want))
+	end
+`
+
+func TestInboundMessageGetters(t *testing.T) {
+	want := &event.InboundMessage{
+		Mailboxes: []string{"mb1", "mb2"},
+		From:      mail.Address{Name: "name1", Address: "addr1"},
+		To: []mail.Address{
+			{Name: "name2", Address: "addr2"},
+			{Name: "name3", Address: "addr3"},
+		},
+		Subject: "subj1",
+		Size:    42,
+	}
+	script := `
+		assert(msg, "msg should not be nil")
+
+		assert_eq(msg.mailboxes, {"mb1", "mb2"})
+		assert_eq(msg.subject, "subj1")
+		assert_eq(msg.size, 42)
+
+		assert_eq(msg.from.name, "name1")
+		assert_eq(msg.from.address, "addr1")
+
+		assert_eq(#msg.to, 2)
+		assert_eq(msg.to[1].name, "name2")
+		assert_eq(msg.to[1].address, "addr2")
+		assert_eq(msg.to[2].name, "name3")
+		assert_eq(msg.to[2].address, "addr3")
+	`
+
+	ls := lua.NewState()
+	registerInboundMessageType(ls)
+	registerMailAddressType(ls)
+	ls.SetGlobal("msg", wrapInboundMessage(ls, want))
+	require.NoError(t, ls.DoString(LuaInit+script))
+}
+
+func TestInboundMessageSetters(t *testing.T) {
+	want := &event.InboundMessage{
+		Mailboxes: []string{"mb1", "mb2"},
+		From:      mail.Address{Name: "name1", Address: "addr1"},
+		To: []mail.Address{
+			{Name: "name2", Address: "addr2"},
+			{Name: "name3", Address: "addr3"},
+		},
+		Subject: "subj1",
+	}
+	script := `
+		assert(msg, "msg should not be nil")
+
+		msg.mailboxes = {"mb1", "mb2"}
+		msg.subject = "subj1"
+		msg.from = address.new("name1", "addr1")
+		msg.to = { address.new("name2", "addr2"), address.new("name3", "addr3") }
+	`
+
+	got := &event.InboundMessage{}
+	ls := lua.NewState()
+	registerInboundMessageType(ls)
+	registerMailAddressType(ls)
+	ls.SetGlobal("msg", wrapInboundMessage(ls, got))
+	require.NoError(t, ls.DoString(script))
+
+	assert.Equal(t, want, got)
+}