chore: Add more Stateful Component tests (#12438) 13be041786

Adds several more real world tests for Stateful Components. Tests also uncovered 2 bugs which are fixed in this PR.
- Fixes cross file copy/pasting stateful artboards to make sure any VM instances that are copied are correctly reparented when pasted.
- We missed the VM artboard property bound to NestedArtboard's artboard case. Fixed, so now we always setup/cleanup new stateful VM instances when artboards are swapped via databinding.

Co-authored-by: Philip Chung <philterdesign@gmail.com>

Author: philter

.rive_head

@@ -1 +1 @@
-ee268b5467f8f4bf67ad634d31a5b8e3e9ff6c71
+13be041786e7811cffc3d5a7a474357619625536

src/nested_artboard.cpp

@@ -139,6 +139,7 @@ void NestedArtboard::updateArtboard(
             m_referencedArtboard = nullptr;
         }
         m_Instance = nullptr;
+        m_statefulViewModelInstance = nullptr;
         return;
     }
 
@@ -159,6 +160,33 @@ void NestedArtboard::updateArtboard(
                 nestedStateMachine)); // take ownership
         }
         referencedArtboard(artboardInstance.release());
+
+        if (artboard->isStateful())
+        {
+            const bool cacheStale =
+                m_statefulViewModelInstance == nullptr ||
+                m_statefulViewModelInstance->viewModelId() !=
+                    artboard->viewModelId();
+            if (cacheStale)
+            {
+                auto vm = m_file != nullptr
+                              ? m_file->viewModel(artboard->viewModelId())
+                              : nullptr;
+                m_statefulViewModelInstance =
+                    vm != nullptr ? m_file->createDefaultViewModelInstance(vm)
+                                  : nullptr;
+                if (m_statefulViewModelInstance != nullptr)
+                {
+                    m_file->completeViewModelProperties(
+                        m_statefulViewModelInstance.get());
+                }
+            }
+        }
+        else
+        {
+            m_statefulViewModelInstance = nullptr;
+        }
+
         if (viewModelInstanceArtboard->boundViewModelInstance())
         {
             bindViewModelInstance(