fix(engine): Do not stop if StopTrigger is not set

The TriggerableCompositeNode was executing actions only until they succeeded, but according to the standard, it shall never finish if no StopTrigger is defined and also until the StopTrigger is satisfied.

engine/src/nodes/front_end/TriggerableCompositeNode.h

@@ -17,6 +17,7 @@
 
 #include <cassert>
 #include <memory>
+#include "agnostic_behavior_tree/behavior_node.h"
 
 namespace yase
 {
@@ -99,6 +100,8 @@ using StopTriggerPtr = StrongNodePtr<struct StopTriggerTag>;
 ///    └─ StartTrigger - optional
 ///       └─ Child     - mandatory
 ///
+/// @note According to the standard, the node never finishes if no StopTrigger
+///       is defined, but the inner structure will be ticked every time.
 class TriggerableCompositeNode : public CompositeNode
 {
 public:
@@ -194,25 +197,24 @@ private:
   }
 
   ///@brief tick as if no triggers would decorate the child
-  NodeStatus tickWithoutTriggers()
+  void tickWithoutTriggers()
   {
     const auto status = m_child_node->executeTick();
     if (status == NodeStatus::kFailure)
     {
       throw std::runtime_error("Child reported failure");
     }
-    return status;
   }
 
   ///@brief tick as if no stop trigger would decorate the start trigger
-  NodeStatus tickWithStartTrigger()
+  void tickWithStartTrigger()
   {
     if (start_trigger_node_)
     {
       const auto status = start_trigger_node_->executeTick();
       if (status == NodeStatus::kRunning)
       {
-        return status;
+        return;
       }
       if (status == NodeStatus::kFailure)
       {
@@ -221,7 +223,7 @@ private:
     }
 
     // descent to next hierarchy level
-    return tickWithoutTriggers();
+    tickWithoutTriggers();
   }
 
   ///@brief tick the highest level, i.e. starting with the (optional) stop trigger
@@ -241,7 +243,10 @@ private:
     }
 
     // descent to next hierarchy level
-    return tickWithStartTrigger();
+    tickWithStartTrigger();
+
+    // don't consider children on purpose (see class description)
+    return NodeStatus::kRunning;
   }
 
   TransientNode::Ptr stop_trigger_node_{nullptr};