feat: DeleteMessageReaction and DeleteAllMessageReactions

Admin removal of a sender's reactions: messages.deleteParticipantReaction
(single message) and messages.deleteParticipantReactions (whole chat). sender is
a ChatID resolving to the user or chat whose reactions are removed. Mapping
confirmed against the telegram-bot-api 10.1 reference. Hermetic tests; lint
clean.

Author: ernado

reactions.go

@@ -77,3 +77,53 @@ func (b *Bot) SetMessageReaction(ctx context.Context, chat ChatID, messageID int
 
 	return nil
 }
+
+// DeleteMessageReaction removes all reactions left by the given sender on a
+// single message. The bot must be an administrator with the can_delete_messages
+// right. sender identifies the user or chat whose reactions are removed.
+func (b *Bot) DeleteMessageReaction(ctx context.Context, chat ChatID, messageID int, sender ChatID) error {
+	peer, err := b.resolveInputPeer(ctx, chat)
+	if err != nil {
+		return err
+	}
+
+	participant, err := b.resolveInputPeer(ctx, sender)
+	if err != nil {
+		return err
+	}
+
+	if _, err := b.raw.MessagesDeleteParticipantReaction(ctx, &tg.MessagesDeleteParticipantReactionRequest{
+		Peer:        peer,
+		MsgID:       messageID,
+		Participant: participant,
+	}); err != nil {
+		return asAPIError(err)
+	}
+
+	return nil
+}
+
+// DeleteAllMessageReactions removes all reactions left by the given sender across
+// every message in a chat. The bot must be an administrator with the
+// can_delete_messages right. sender identifies the user or chat whose reactions
+// are removed.
+func (b *Bot) DeleteAllMessageReactions(ctx context.Context, chat, sender ChatID) error {
+	peer, err := b.resolveInputPeer(ctx, chat)
+	if err != nil {
+		return err
+	}
+
+	participant, err := b.resolveInputPeer(ctx, sender)
+	if err != nil {
+		return err
+	}
+
+	if _, err := b.raw.MessagesDeleteParticipantReactions(ctx, &tg.MessagesDeleteParticipantReactionsRequest{
+		Peer:        peer,
+		Participant: participant,
+	}); err != nil {
+		return asAPIError(err)
+	}
+
+	return nil
+}

reactions_test.go

@@ -70,6 +70,44 @@ func TestReactionToTgCustomEmoji(t *testing.T) {
 	}
 }
 
+func TestDeleteMessageReaction(t *testing.T) {
+	inv := newMockInvoker()
+	inv.reply(tg.MessagesDeleteParticipantReactionRequestTypeID, okUpdates())
+
+	if err := newMockBot(inv).DeleteMessageReaction(context.Background(), tdlibChannel(50), 42, userRef(60, 1)); err != nil {
+		t.Fatalf("DeleteMessageReaction: %v", err)
+	}
+
+	var req tg.MessagesDeleteParticipantReactionRequest
+
+	inv.decode(t, tg.MessagesDeleteParticipantReactionRequestTypeID, &req)
+
+	if req.MsgID != 42 {
+		t.Fatalf("msg id = %d", req.MsgID)
+	}
+
+	if _, ok := req.Participant.(*tg.InputPeerUser); !ok {
+		t.Fatalf("participant = %#v, want user", req.Participant)
+	}
+}
+
+func TestDeleteAllMessageReactions(t *testing.T) {
+	inv := newMockInvoker()
+	inv.reply(tg.MessagesDeleteParticipantReactionsRequestTypeID, &tg.BoolTrue{})
+
+	if err := newMockBot(inv).DeleteAllMessageReactions(context.Background(), tdlibChannel(50), userRef(60, 1)); err != nil {
+		t.Fatalf("DeleteAllMessageReactions: %v", err)
+	}
+
+	var req tg.MessagesDeleteParticipantReactionsRequest
+
+	inv.decode(t, tg.MessagesDeleteParticipantReactionsRequestTypeID, &req)
+
+	if _, ok := req.Participant.(*tg.InputPeerUser); !ok {
+		t.Fatalf("participant = %#v, want user", req.Participant)
+	}
+}
+
 func TestChatJoinRequests(t *testing.T) {
 	for _, c := range []struct {
 		name     string