Rename -[ASCellNode viewModel] to -[ASCellNode nodeViewModel] to avoid collisions (#499)

* Rename -[ASCellNode viewModel] -> -[ASCellNode nodeViewModel] to avoid breaking existing code

* Update test

* Update the changelog

CHANGELOG.md

@@ -13,6 +13,7 @@
 - Add -[ASDisplayNode detailedLayoutDescription] property to aid debugging. [Adlai Holler](https://github.com/Adlai-Holler) [#476](https://github.com/TextureGroup/Texture/pull/476)
 - Fix an issue that causes calculatedLayoutDidChange being called needlessly. [Huy Nguyen](https://github.com/nguyenhuy) [#490](https://github.com/TextureGroup/Texture/pull/490)
 - Negate iOS 11 automatic estimated table row heights. [Christian Selig](https://github.com/christianselig) [#485](https://github.com/TextureGroup/Texture/pull/485)
+- Rename ASCellNode.viewModel to ASCellNode.nodeViewModel to reduce collisions with subclass properties implemented by clients. [Adlai Holler](https://github.com/Adlai-Holler) [#499](https://github.com/TextureGroup/Texture/pull/499)
 
 ##2.3.5
 - Fix an issue where inserting/deleting sections could lead to inconsistent supplementary element behavior. [Adlai Holler](https://github.com/Adlai-Holler)

Source/ASCellNode.h

@@ -123,7 +123,7 @@ typedef NS_ENUM(NSUInteger, ASCellNodeVisibilityEvent) {
  *
  * This property may be set off the main thread, but this method will never be invoked concurrently on the 
  */
-@property (atomic, nullable) id viewModel;
+@property (atomic, nullable) id nodeViewModel;
 
 /**
  * Asks the node whether it can be updated to the given view model.

Source/ASCellNode.mm

@@ -172,7 +172,7 @@
 
 - (BOOL)canUpdateToViewModel:(id)viewModel
 {
-  return [self.viewModel class] == [viewModel class];
+  return [self.nodeViewModel class] == [viewModel class];
 }
 
 - (NSIndexPath *)indexPath

Source/Details/ASCollectionElement.mm

@@ -64,7 +64,7 @@
     node.owningNode = _owningNode;
     node.collectionElement = self;
     ASTraitCollectionPropagateDown(node, _traitCollection);
-    node.viewModel = _viewModel;
+    node.nodeViewModel = _viewModel;
     _node = node;
   }
   return _node;

Tests/ASCollectionModernDataSourceTests.m

@@ -254,7 +254,7 @@
       id viewModel = viewModels[indexPath.item];
       XCTAssertEqualObjects(viewModel, [collectionNode viewModelForItemAtIndexPath:indexPath]);
       ASCellNode *node = [collectionNode nodeForItemAtIndexPath:indexPath];
-      XCTAssertEqualObjects(node.viewModel, viewModel);
+      XCTAssertEqualObjects(node.nodeViewModel, viewModel);
     }
   }
 }