Prevent Adding View-Backed Nodes to Layer-Backed Hierarchies (#3062)

* Prevent adding view-backed nodes to layer-backed nodes

* Do that in a different diff

* Fix the message

* Update tests

* Fix the fix

Author: Adlai Holler

AsyncDisplayKit/ASDisplayNode.mm

@@ -2543,6 +2543,11 @@ - (void)_insertSubnode:(ASDisplayNode *)subnode atSubnodeIndex:(NSInteger)subnod
     return;
   }
 
+  if (self.layerBacked && !subnode.layerBacked) {
+    ASDisplayNodeFailAssert(@"Cannot add a view-backed node as a subnode of a layer-backed node. Supernode: %@, subnode: %@", self, subnode);
+    return;
+  }
+
   __instanceLock__.lock();
     NSUInteger subnodesCount = _subnodes.count;
   __instanceLock__.unlock();
@@ -3169,7 +3174,7 @@ - (void)setHierarchyState:(ASHierarchyState)newState
     ASDisplayNodeAssert(_flags.synchronous == NO, @"Node created using -initWithViewBlock:/-initWithLayerBlock: cannot be added to subtree of node with shouldRasterizeDescendants=YES. Node: %@", self);
   }
 
-  // Entered or exited contents rendering state.
+  // Entered or exited range managed state.
   if ((newState & ASHierarchyStateRangeManaged) != (oldState & ASHierarchyStateRangeManaged)) {
     if (newState & ASHierarchyStateRangeManaged) {
       [self enterInterfaceState:self.supernode.interfaceState];

AsyncDisplayKitTests/ASDisplayNodeTests.mm

@@ -1098,33 +1098,34 @@ - (void)testSubnodes
 
 - (void)testReplaceSubnodeNoView
 {
-  [self checkReplaceSubnodeWithView:NO layerBacked:NO];
+  [self checkReplaceSubnodeLoaded:NO layerBacked:NO];
 }
 
 - (void)testReplaceSubnodeNoLayer
 {
-  [self checkReplaceSubnodeWithView:NO layerBacked:YES];
+  [self checkReplaceSubnodeLoaded:NO layerBacked:YES];
 }
 
 - (void)testReplaceSubnodeView
 {
-  [self checkReplaceSubnodeWithView:YES layerBacked:NO];
+  [self checkReplaceSubnodeLoaded:YES layerBacked:NO];
 }
 
 - (void)testReplaceSubnodeLayer
 {
-  [self checkReplaceSubnodeWithView:YES layerBacked:YES];
+  [self checkReplaceSubnodeLoaded:YES layerBacked:YES];
 }
 
 
-- (void)checkReplaceSubnodeWithView:(BOOL)loaded layerBacked:(BOOL)isLayerBacked
+- (void)checkReplaceSubnodeLoaded:(BOOL)loaded layerBacked:(BOOL)isLayerBacked
 {
   DeclareNodeNamed(parent);
   DeclareNodeNamed(a);
   DeclareNodeNamed(b);
   DeclareNodeNamed(c);
+  DeclareNodeNamed(d);
 
-  for (ASDisplayNode *n in @[parent, a, b, c]) {
+  for (ASDisplayNode *n in @[parent, a, b, c, d]) {
     n.layerBacked = isLayerBacked;
   }
 
@@ -1136,7 +1137,6 @@ - (void)checkReplaceSubnodeWithView:(BOOL)loaded layerBacked:(BOOL)isLayerBacked
     [parent layer];
   }
 
-  DeclareNodeNamed(d);
   if (loaded) {
     XCTAssertFalse(d.nodeLoaded, @"Should not yet be loaded");
   }

examples/ASDKgram/Sample/CommentsNode.m

@@ -96,6 +96,7 @@ - (void)createCommentLabels
   for (NSUInteger i = 0; i < numLabelsToAdd; i++) {
 
     ASTextNode *commentLabel   = [[ASTextNode alloc] init];
+    commentLabel.layerBacked = YES;
     commentLabel.maximumNumberOfLines = 3;
 
     [_commentNodes addObject:commentLabel];