feat: AnswerGuestQuery

messages.setBotGuestChatResult with the InlineQueryResult.toTg machinery; returns
the sent inline message id (SentWebAppMessage), mirroring AnswerWebAppQuery.
Mapping confirmed against telegram-bot-api 10.1. Hermetic tests; lint clean.

Author: ernado

answer_guest.go

@@ -0,0 +1,43 @@
+package botapi
+
+import (
+	"context"
+	"strconv"
+
+	"github.com/gotd/td/tg"
+)
+
+// AnswerGuestQuery sets the result of a guest interaction with the bot and sends
+// a corresponding message to the chat from which the query originated.
+// guestQueryID is the query id received in the update. It returns the sent
+// inline message id.
+func (b *Bot) AnswerGuestQuery(ctx context.Context, guestQueryID string, result InlineQueryResult) (*SentWebAppMessage, error) {
+	if result == nil {
+		return nil, errNilInlineResult()
+	}
+
+	queryID, err := strconv.ParseInt(guestQueryID, 10, 64)
+	if err != nil {
+		return nil, &Error{Code: 400, Description: "Bad Request: invalid guest_query_id"}
+	}
+
+	converted, err := result.toTg(ctx, b)
+	if err != nil {
+		return nil, err
+	}
+
+	res, err := b.raw.MessagesSetBotGuestChatResult(ctx, &tg.MessagesSetBotGuestChatResultRequest{
+		QueryID: queryID,
+		Result:  converted,
+	})
+	if err != nil {
+		return nil, asAPIError(err)
+	}
+
+	enc, err := encodeInlineMessageID(res)
+	if err != nil {
+		return nil, err
+	}
+
+	return &SentWebAppMessage{InlineMessageID: enc}, nil
+}

answer_guest_test.go

@@ -0,0 +1,60 @@
+package botapi
+
+import (
+	"context"
+	"testing"
+
+	"github.com/gotd/td/tg"
+)
+
+func TestAnswerGuestQuery(t *testing.T) {
+	mid := &tg.InputBotInlineMessageID64{DCID: 2, OwnerID: 1, ID: 9, AccessHash: 42}
+
+	inv := newMockInvoker()
+	inv.reply(tg.MessagesSetBotGuestChatResultRequestTypeID, mid)
+
+	result := &InlineQueryResultArticle{
+		ID:                  "r1",
+		Title:               "Title",
+		InputMessageContent: &InputTextMessageContent{MessageText: "hi"},
+	}
+
+	got, err := newMockBot(inv).AnswerGuestQuery(context.Background(), "12345", result)
+	if err != nil {
+		t.Fatalf("AnswerGuestQuery: %v", err)
+	}
+
+	decoded, err := decodeInlineMessageID(got.InlineMessageID)
+	if err != nil {
+		t.Fatalf("decode inline message id: %v", err)
+	}
+
+	if decoded.String() != mid.String() {
+		t.Fatalf("inline message id = %#v, want %#v", decoded, mid)
+	}
+
+	var req tg.MessagesSetBotGuestChatResultRequest
+
+	inv.decode(t, tg.MessagesSetBotGuestChatResultRequestTypeID, &req)
+
+	if req.QueryID != 12345 {
+		t.Fatalf("query id = %d", req.QueryID)
+	}
+
+	if _, ok := req.Result.(*tg.InputBotInlineResult); !ok {
+		t.Fatalf("result = %#v, want inline result", req.Result)
+	}
+}
+
+func TestAnswerGuestQueryInvalid(t *testing.T) {
+	inv := newMockInvoker()
+
+	if _, err := newMockBot(inv).AnswerGuestQuery(context.Background(), "12345", nil); err == nil {
+		t.Fatal("expected error for nil result")
+	}
+
+	if _, err := newMockBot(inv).AnswerGuestQuery(context.Background(), "notanumber",
+		&InlineQueryResultArticle{ID: "r1", Title: "T", InputMessageContent: &InputTextMessageContent{MessageText: "x"}}); err == nil {
+		t.Fatal("expected error for invalid guest_query_id")
+	}
+}