[ASTableNode & ASCollectionNode] Keepalive reference for node if thei…

…r view is necessarily alive (has a superview). (#793)

* fix SIMULATE_WEB_RESPONSE not imported #449

* Fix to make rangeMode update in right time

* Keep collection/table node alive if view still in use.

Source/ASCollectionNode.mm

@@ -172,6 +172,13 @@ - (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionVi
   return self;
 }
 
+- (void)dealloc
+{
+  if ([self isNodeLoaded]) {
+    ASDisplayNodeAssert(self.view.superview == nil, @"Node's view should be removed from hierarchy.");
+  }
+}
+
 #pragma mark ASDisplayNode
 
 - (void)didLoad

Source/ASCollectionView.mm

@@ -151,7 +151,12 @@ @interface ASCollectionView () <ASRangeControllerDataSource, ASRangeControllerDe
    * Counter used to keep track of nested batch updates.
    */
   NSInteger _batchUpdateCount;
-
+
+  /**
+   * Keep a strong reference to node till view is ready to release.
+   */
+  ASCollectionNode *_keepalive_node;
+
   struct {
     unsigned int scrollViewDidScroll:1;
     unsigned int scrollViewWillBeginDragging:1;
@@ -2250,6 +2255,20 @@ - (void)didMoveToWindow
   }
 }
 
+- (void)willMoveToSuperview:(UIView *)newSuperview
+{
+  if (self.superview == nil && newSuperview != nil) {
+    _keepalive_node = self.collectionNode;
+  }
+}
+
+- (void)didMoveToSuperview
+{
+  if (self.superview == nil) {
+    _keepalive_node = nil;
+  }
+}
+
 #pragma mark ASCALayerExtendedDelegate
 
 /**

Source/ASTableNode.mm

@@ -104,6 +104,13 @@ - (instancetype)init
   return [self initWithStyle:UITableViewStylePlain];
 }
 
+- (void)dealloc
+{
+  if ([self isNodeLoaded]) {
+    ASDisplayNodeAssert(self.view.superview == nil, @"Node's view should be removed from hierarchy.");
+  }
+}
+
 #pragma mark ASDisplayNode
 
 - (void)didLoad

Source/ASTableView.mm

@@ -216,7 +216,12 @@ @interface ASTableView () <ASRangeControllerDataSource, ASRangeControllerDelegat
    * Counter used to keep track of nested batch updates.
    */
   NSInteger _batchUpdateCount;
-
+
+  /**
+   * Keep a strong reference to node till view is ready to release.
+   */
+  ASTableNode *_keepalive_node;
+
   struct {
     unsigned int scrollViewDidScroll:1;
     unsigned int scrollViewWillBeginDragging:1;
@@ -1913,4 +1918,18 @@ - (void)didMoveToWindow
   }
 }
 
+- (void)willMoveToSuperview:(UIView *)newSuperview
+{
+  if (self.superview == nil && newSuperview != nil) {
+    _keepalive_node = self.tableNode;
+  }
+}
+
+- (void)didMoveToSuperview
+{
+  if (self.superview == nil) {
+    _keepalive_node = nil;
+  }
+}
+
 @end

Tests/ASCollectionViewTests.mm

@@ -1071,6 +1071,7 @@ - (void)testInitialRangeBounds
       for (NSInteger i = 0; i < c; i++) {
         NSIndexPath *ip = [NSIndexPath indexPathForItem:i inSection:s];
         ASCellNode *node = [cn nodeForItemAtIndexPath:ip];
+        [[NSRunLoop mainRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:0.001]];
         if (node.inPreloadState) {
           CGRect frame = [cn.view layoutAttributesForItemAtIndexPath:ip].frame;
           r = CGRectUnion(r, frame);