Fix signal connection nodiscard warnings (#4818)

src/providers/twitch/TwitchAccountManager.cpp

@@ -20,7 +20,9 @@ TwitchAccountManager::TwitchAccountManager()
         currentUser->loadSeventvUserID();
     });
 
-    this->accounts.itemRemoved.connect([this](const auto &acc) {
+    // We can safely ignore this signal connection since accounts will always be removed
+    // before TwitchAccountManager
+    std::ignore = this->accounts.itemRemoved.connect([this](const auto &acc) {
         this->removeUser(acc.item.get());
     });
 }

src/providers/twitch/TwitchChannel.cpp

@@ -94,25 +94,15 @@ TwitchChannel::TwitchChannel(const QString &name)
         }));
 
     this->refreshPubSub();
-    this->userStateChanged.connect([this] {
+    // We can safely ignore this signal connection since it's a private signal, meaning
+    // it will only ever be invoked by TwitchChannel itself
+    std::ignore = this->userStateChanged.connect([this] {
         this->refreshPubSub();
     });
 
-    // room id loaded -> refresh live status
-    this->roomIdChanged.connect([this]() {
-        this->refreshPubSub();
-        this->refreshBadges();
-        this->refreshCheerEmotes();
-        this->refreshFFZChannelEmotes(false);
-        this->refreshBTTVChannelEmotes(false);
-        this->refreshSevenTVChannelEmotes(false);
-        this->joinBttvChannel();
-        this->listenSevenTVCosmetics();
-        getIApp()->getTwitchLiveController()->add(
-            std::dynamic_pointer_cast<TwitchChannel>(shared_from_this()));
-    });
-
-    this->connected.connect([this]() {
+    // We can safely ignore this signal connection this has no external dependencies - once the signal
+    // is destroyed, it will no longer be able to fire
+    std::ignore = this->connected.connect([this]() {
         if (this->roomId().isEmpty())
         {
             // If we get a reconnected event when the room id is not set, we
@@ -125,18 +115,7 @@ TwitchChannel::TwitchChannel(const QString &name)
         this->loadRecentMessagesReconnect();
     });
 
-    this->messageRemovedFromStart.connect([this](MessagePtr &msg) {
-        if (msg->replyThread)
-        {
-            if (msg->replyThread->liveCount(msg) == 0)
-            {
-                this->threads_.erase(msg->replyThread->rootId());
-            }
-        }
-    });
-
     // timers
-
     QObject::connect(&this->chattersListTimer_, &QTimer::timeout, [this] {
         this->refreshChatters();
     });
@@ -538,6 +517,20 @@ void TwitchChannel::showLoginMessage()
     this->addMessage(builder.release());
 }
 
+void TwitchChannel::roomIdChanged()
+{
+    this->refreshPubSub();
+    this->refreshBadges();
+    this->refreshCheerEmotes();
+    this->refreshFFZChannelEmotes(false);
+    this->refreshBTTVChannelEmotes(false);
+    this->refreshSevenTVChannelEmotes(false);
+    this->joinBttvChannel();
+    this->listenSevenTVCosmetics();
+    getIApp()->getTwitchLiveController()->add(
+        std::dynamic_pointer_cast<TwitchChannel>(shared_from_this()));
+}
+
 QString TwitchChannel::prepareMessage(const QString &message) const
 {
     auto app = getApp();
@@ -729,7 +722,7 @@ void TwitchChannel::setRoomId(const QString &id)
     if (*this->roomID_.accessConst() != id)
     {
         *this->roomID_.access() = id;
-        this->roomIdChanged.invoke();
+        this->roomIdChanged();
         this->loadRecentMessages();
     }
 }
@@ -1063,6 +1056,17 @@ bool TwitchChannel::tryReplaceLastLiveUpdateAddOrRemove(
     return true;
 }
 
+void TwitchChannel::messageRemovedFromStart(const MessagePtr &msg)
+{
+    if (msg->replyThread)
+    {
+        if (msg->replyThread->liveCount(msg) == 0)
+        {
+            this->threads_.erase(msg->replyThread->rootId());
+        }
+    }
+}
+
 const QString &TwitchChannel::subscriptionUrl()
 {
     return this->subscriptionUrl_;

src/providers/twitch/TwitchChannel.hpp

@@ -191,8 +191,7 @@ public:
     const std::unordered_map<QString, std::weak_ptr<MessageThread>> &threads()
         const;
 
-    // Signals
-    pajlada::Signals::NoArgSignal roomIdChanged;
+    // Only TwitchChannel may invoke this signal
     pajlada::Signals::NoArgSignal userStateChanged;
 
     /**
@@ -242,8 +241,6 @@ private:
         QString actualDisplayName;
     } nameOptions;
 
-private:
-    // Methods
     void refreshPubSub();
     void refreshChatters();
     void refreshBadges();
@@ -252,6 +249,11 @@ private:
     void loadRecentMessagesReconnect();
     void cleanUpReplyThreads();
     void showLoginMessage();
+
+    /// roomIdChanged is called whenever this channel's ID has been changed
+    /// This should only happen once per channel, whenever the ID goes from unset to set
+    void roomIdChanged();
+
     /** Joins (subscribes to) a Twitch channel for updates on BTTV. */
     void joinBttvChannel() const;
     /**
@@ -335,6 +337,8 @@ private:
     std::unordered_map<QString, std::weak_ptr<MessageThread>> threads_;
 
 protected:
+    void messageRemovedFromStart(const MessagePtr &msg) override;
+
     Atomic<std::shared_ptr<const EmoteMap>> bttvEmotes_;
     Atomic<std::shared_ptr<const EmoteMap>> ffzEmotes_;
     Atomic<std::shared_ptr<const EmoteMap>> seventvEmotes_;

src/providers/twitch/TwitchIrcServer.cpp

@@ -133,21 +133,24 @@ void TwitchIrcServer::initializeConnection(IrcConnection *connection,
 std::shared_ptr<Channel> TwitchIrcServer::createChannel(
     const QString &channelName)
 {
-    auto channel =
-        std::shared_ptr<TwitchChannel>(new TwitchChannel(channelName));
+    auto channel = std::make_shared<TwitchChannel>(channelName);
     channel->initialize();
 
-    channel->sendMessageSignal.connect(
+    // We can safely ignore these signal connections since the TwitchIrcServer is only
+    // ever destroyed when the full Application state is about to be destroyed, at which point
+    // no Channel's should live
+    // NOTE: CHANNEL_LIFETIME
+    std::ignore = channel->sendMessageSignal.connect(
         [this, channel = channel.get()](auto &chan, auto &msg, bool &sent) {
             this->onMessageSendRequested(channel, msg, sent);
         });
-    channel->sendReplySignal.connect(
+    std::ignore = channel->sendReplySignal.connect(
         [this, channel = channel.get()](auto &chan, auto &msg, auto &replyId,
                                         bool &sent) {
             this->onReplySendRequested(channel, msg, replyId, sent);
         });
 
-    return std::shared_ptr<Channel>(channel);
+    return channel;
 }
 
 void TwitchIrcServer::privateMessageReceived(