Inject an ASDataController class to ASTableView, for testing purposes

- Injection can be done via a new internal initializer. The class will be used by ASTableView to create (and configure) a new data controller.
- ASTableViewTests now injects its own type of ASDataController. This facilitates new ways for testing ASTableView-specific behaviours. The first application is counting the number of times relayoutAllNodes is called on the data controller.

AsyncDisplayKit.xcodeproj/project.pbxproj

@@ -254,6 +254,8 @@
 		AC47D9451B3BB41900AAEE9D /* ASRelativeSize.h in Headers */ = {isa = PBXBuildFile; fileRef = AC47D9431B3BB41900AAEE9D /* ASRelativeSize.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		AC47D9461B3BB41900AAEE9D /* ASRelativeSize.mm in Sources */ = {isa = PBXBuildFile; fileRef = AC47D9441B3BB41900AAEE9D /* ASRelativeSize.mm */; };
 		AC6456091B0A335000CF11B8 /* ASCellNode.m in Sources */ = {isa = PBXBuildFile; fileRef = AC6456071B0A335000CF11B8 /* ASCellNode.m */; };
+		AC7A2C171BDE11DF0093FE1A /* ASTableViewInternal.h in Headers */ = {isa = PBXBuildFile; fileRef = AC7A2C161BDE11DF0093FE1A /* ASTableViewInternal.h */; };
+		AC7A2C181BDE11DF0093FE1A /* ASTableViewInternal.h in Headers */ = {isa = PBXBuildFile; fileRef = AC7A2C161BDE11DF0093FE1A /* ASTableViewInternal.h */; };
 		ACC945A91BA9E7A0005E1FB8 /* ASViewController.h in Headers */ = {isa = PBXBuildFile; fileRef = ACC945A81BA9E7A0005E1FB8 /* ASViewController.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		ACC945AB1BA9E7C1005E1FB8 /* ASViewController.m in Sources */ = {isa = PBXBuildFile; fileRef = ACC945AA1BA9E7C1005E1FB8 /* ASViewController.m */; };
 		ACF6ED1A1B17843500DA7C62 /* ASBackgroundLayoutSpec.h in Headers */ = {isa = PBXBuildFile; fileRef = ACF6ED011B17843500DA7C62 /* ASBackgroundLayoutSpec.h */; settings = {ATTRIBUTES = (Public, ); }; };
@@ -617,6 +619,7 @@
 		AC47D9431B3BB41900AAEE9D /* ASRelativeSize.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = ASRelativeSize.h; path = AsyncDisplayKit/Layout/ASRelativeSize.h; sourceTree = "<group>"; };
 		AC47D9441B3BB41900AAEE9D /* ASRelativeSize.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; name = ASRelativeSize.mm; path = AsyncDisplayKit/Layout/ASRelativeSize.mm; sourceTree = "<group>"; };
 		AC6456071B0A335000CF11B8 /* ASCellNode.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ASCellNode.m; sourceTree = "<group>"; };
+		AC7A2C161BDE11DF0093FE1A /* ASTableViewInternal.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASTableViewInternal.h; sourceTree = "<group>"; };
 		ACC945A81BA9E7A0005E1FB8 /* ASViewController.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASViewController.h; sourceTree = "<group>"; };
 		ACC945AA1BA9E7C1005E1FB8 /* ASViewController.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ASViewController.m; sourceTree = "<group>"; };
 		ACF6ED011B17843500DA7C62 /* ASBackgroundLayoutSpec.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = ASBackgroundLayoutSpec.h; path = AsyncDisplayKit/Layout/ASBackgroundLayoutSpec.h; sourceTree = "<group>"; };
@@ -803,6 +806,7 @@
 				D785F6611A74327E00291744 /* ASScrollNode.m */,
 				055F1A3219ABD3E3004DAFF1 /* ASTableView.h */,
 				055F1A3319ABD3E3004DAFF1 /* ASTableView.mm */,
+				AC7A2C161BDE11DF0093FE1A /* ASTableViewInternal.h */,
 				0574D5E119C110610097DC25 /* ASTableViewProtocols.h */,
 				058D09DF195D050800B7D73C /* ASTextNode.h */,
 				058D09E0195D050800B7D73C /* ASTextNode.mm */,
@@ -1128,6 +1132,7 @@
 				058D0A4C195D05CB00B7D73C /* ASDisplayNode+Subclasses.h in Headers */,
 				058D0A4A195D05CB00B7D73C /* ASDisplayNode.h in Headers */,
 				058D0A84195D060300B7D73C /* ASDisplayNodeExtraIvars.h in Headers */,
+				AC7A2C171BDE11DF0093FE1A /* ASTableViewInternal.h in Headers */,
 				058D0A4D195D05CB00B7D73C /* ASDisplayNodeExtras.h in Headers */,
 				058D0A7B195D05F900B7D73C /* ASDisplayNodeInternal.h in Headers */,
 				0587F9BD1A7309ED00AFF0BA /* ASEditableTextNode.h in Headers */,
@@ -1243,6 +1248,7 @@
 				B350625B1B010F070018CF92 /* ASEqualityHelpers.h in Headers */,
 				B350621B1B010EFD0018CF92 /* ASFlowLayoutController.h in Headers */,
 				B350621D1B010EFD0018CF92 /* ASHighlightOverlayLayer.h in Headers */,
+				AC7A2C181BDE11DF0093FE1A /* ASTableViewInternal.h in Headers */,
 				B35062531B010EFD0018CF92 /* ASImageNode+CGExtras.h in Headers */,
 				B35062021B010EFD0018CF92 /* ASImageNode.h in Headers */,
 				B350621F1B010EFD0018CF92 /* ASImageProtocols.h in Headers */,

AsyncDisplayKit/ASTableView.mm

@@ -7,6 +7,7 @@
  */
 
 #import "ASTableView.h"
+#import "ASTableViewInternal.h"
 
 #import "ASAssert.h"
 #import "ASChangeSetDataController.h"
@@ -155,7 +156,6 @@ static BOOL _isInterceptedSelector(SEL sel)
   _ASTableViewProxy *_proxyDataSource;
   _ASTableViewProxy *_proxyDelegate;
 
-  ASDataController *_dataController;
   ASFlowLayoutController *_layoutController;
 
   ASRangeController *_rangeController;
@@ -174,6 +174,7 @@ static BOOL _isInterceptedSelector(SEL sel)
 }
 
 @property (atomic, assign) BOOL asyncDataSourceLocked;
+@property (nonatomic, retain, readwrite) ASDataController *dataController;
 
 @end
 
@@ -199,10 +200,15 @@ void ASPerformBlockWithoutAnimation(BOOL withoutAnimation, void (^block)()) {
   }
 }
 
++ (Class)dataControllerClass
+{
+  return [ASChangeSetDataController class];
+}
+
 #pragma mark -
 #pragma mark Lifecycle
 
-- (void)configureWithAsyncDataFetching:(BOOL)asyncDataFetchingEnabled
+- (void)configureWithDataControllerClass:(Class)dataControllerClass asyncDataFetching:(BOOL)asyncDataFetching
 {
   _layoutController = [[ASFlowLayoutController alloc] initWithScrollOption:ASFlowLayoutDirectionVertical];
   
@@ -210,13 +216,13 @@ void ASPerformBlockWithoutAnimation(BOOL withoutAnimation, void (^block)()) {
   _rangeController.layoutController = _layoutController;
   _rangeController.delegate = self;
   
-  _dataController = [[ASChangeSetDataController alloc] initWithAsyncDataFetching:asyncDataFetchingEnabled];
+  _dataController = [[dataControllerClass alloc] initWithAsyncDataFetching:asyncDataFetching];
   _dataController.dataSource = self;
   _dataController.delegate = _rangeController;
   
   _layoutController.dataSource = _dataController;
 
-  _asyncDataFetchingEnabled = asyncDataFetchingEnabled;
+  _asyncDataFetchingEnabled = asyncDataFetching;
   _asyncDataSourceLocked = NO;
 
   _leadingScreensForBatching = 1.0;
@@ -236,6 +242,11 @@ void ASPerformBlockWithoutAnimation(BOOL withoutAnimation, void (^block)()) {
 }
 
 - (instancetype)initWithFrame:(CGRect)frame style:(UITableViewStyle)style asyncDataFetching:(BOOL)asyncDataFetchingEnabled
+{
+  return [self initWithFrame:frame style:style dataControllerClass:[self.class dataControllerClass] asyncDataFetching:asyncDataFetchingEnabled];
+}
+
+- (instancetype)initWithFrame:(CGRect)frame style:(UITableViewStyle)style dataControllerClass:(Class)dataControllerClass asyncDataFetching:(BOOL)asyncDataFetchingEnabled
 {
   if (!(self = [super initWithFrame:frame style:style]))
     return nil;
@@ -244,7 +255,7 @@ void ASPerformBlockWithoutAnimation(BOOL withoutAnimation, void (^block)()) {
   // https://github.com/facebook/AsyncDisplayKit/issues/385
   asyncDataFetchingEnabled = NO;
   
-  [self configureWithAsyncDataFetching:asyncDataFetchingEnabled];
+  [self configureWithDataControllerClass:dataControllerClass asyncDataFetching:asyncDataFetchingEnabled];
   
   return self;
 }
@@ -254,7 +265,7 @@ void ASPerformBlockWithoutAnimation(BOOL withoutAnimation, void (^block)()) {
   if (!(self = [super initWithCoder:aDecoder]))
     return nil;
 
-  [self configureWithAsyncDataFetching:NO];
+  [self configureWithDataControllerClass:[self.class dataControllerClass] asyncDataFetching:NO];
 
   return self;
 }

AsyncDisplayKit/ASTableViewInternal.h

@@ -0,0 +1,31 @@
+//
+//  ASTableViewInternal.h
+//  AsyncDisplayKit
+//
+//  Created by Huy Nguyen on 26/10/15.
+//  Copyright (c) 2015 Facebook. All rights reserved.
+//
+
+#import "ASTableView.h"
+
+@class ASDataController;
+
+@interface ASTableView (Internal)
+
+@property (nonatomic, retain, readonly) ASDataController *dataController;
+
+/**
+ * Initializer.
+ *
+ * @param frame A rectangle specifying the initial location and size of the table view in its superview’€™s coordinates.
+ * The frame of the table view changes as table cells are added and deleted.
+ *
+ * @param style A constant that specifies the style of the table view. See UITableViewStyle for descriptions of valid constants.
+ *
+ * @param dataControllerClass A controller class injected to and used to create a data controller for the table view.
+ *
+ * @param asyncDataFetchingEnabled This option is reserved for future use, and currently a no-op.
+ */
+- (instancetype)initWithFrame:(CGRect)frame style:(UITableViewStyle)style dataControllerClass:(Class)dataControllerClass asyncDataFetching:(BOOL)asyncDataFetchingEnabled;
+
+@end

AsyncDisplayKitTests/ASTableViewTests.m

@@ -9,18 +9,44 @@
 #import <XCTest/XCTest.h>
 
 #import "ASTableView.h"
+#import "ASTableViewInternal.h"
 #import "ASDisplayNode+Subclasses.h"
+#import "ASChangeSetDataController.h"
 
 #define NumberOfSections 10
 #define NumberOfRowsPerSection 20
 #define NumberOfReloadIterations 50
 
+@interface ASTestDataController : ASChangeSetDataController
+@property (atomic) int numberOfAllNodesRelayouts;
+@end
+
+@implementation ASTestDataController
+
+- (void)relayoutAllNodes
+{
+  _numberOfAllNodesRelayouts++;
+  [super relayoutAllNodes];
+}
+
+@end
+
 @interface ASTestTableView : ASTableView
 @property (atomic, copy) void (^willDeallocBlock)(ASTableView *tableView);
 @end
 
 @implementation ASTestTableView
 
+- (instancetype)initWithFrame:(CGRect)frame style:(UITableViewStyle)style asyncDataFetching:(BOOL)asyncDataFetchingEnabled
+{
+  return [super initWithFrame:frame style:style dataControllerClass:[ASTestDataController class] asyncDataFetching:asyncDataFetchingEnabled];
+}
+
+- (ASTestDataController *)testDataController
+{
+  return (ASTestDataController *)self.dataController;
+}
+
 - (void)dealloc
 {
   if (_willDeallocBlock) {
@@ -219,7 +245,7 @@
   }
 }
 
-- (void)testRelayoutAllRowsWithNonZeroSizeInitially
+- (void)testRelayoutAllNodesWithNonZeroSizeInitially
 {
   // Initial width of the table view is non-zero and all nodes are measured with this size.
   // Any subsequence size change must trigger a relayout.
@@ -234,11 +260,13 @@
   tableView.asyncDelegate = dataSource;
   tableView.asyncDataSource = dataSource;
 
-  [self triggerFirstLayoutMeasurementForTableView:tableView];
+  [tableView layoutIfNeeded];
-  [self triggerSizeChangeAndAssertRelayoutAllRowsForTableView:tableView newSize:tableViewFinalSize];
+  
+  XCTAssertEqual(tableView.testDataController.numberOfAllNodesRelayouts, 0);
+  [self triggerSizeChangeAndAssertRelayoutAllNodesForTableView:tableView newSize:tableViewFinalSize];
 }
 
-- (void)testRelayoutAllRowsWithZeroSizeInitially
+- (void)testRelayoutAllNodesWithZeroSizeInitially
 {
   // Initial width of the table view is 0. The first size change is part of the initial config.
   // Any subsequence size change after that must trigger a relayout.
@@ -256,10 +284,10 @@
   [superview addSubview:tableView];
   // Width and height are swapped so that a later size change will simulate a rotation
   tableView.frame = CGRectMake(0, 0, tableViewFinalSize.height, tableViewFinalSize.width);
-  // Trigger layout measurement on all nodes
   [tableView layoutIfNeeded];
   
-  [self triggerSizeChangeAndAssertRelayoutAllRowsForTableView:tableView newSize:tableViewFinalSize];
+  XCTAssertEqual(tableView.testDataController.numberOfAllNodesRelayouts, 0);
+  [self triggerSizeChangeAndAssertRelayoutAllNodesForTableView:tableView newSize:tableViewFinalSize];
 }
 
 - (void)testRelayoutVisibleRowsWhenEditingModeIsChanged
@@ -407,7 +435,7 @@
   }];
 }
 
-- (void)triggerSizeChangeAndAssertRelayoutAllRowsForTableView:(ASTableView *)tableView newSize:(CGSize)newSize
+- (void)triggerSizeChangeAndAssertRelayoutAllNodesForTableView:(ASTestTableView *)tableView newSize:(CGSize)newSize
 {
   XCTestExpectation *nodesMeasuredUsingNewConstrainedSizeExpectation = [self expectationWithDescription:@"nodesMeasuredUsingNewConstrainedSize"];
   
@@ -419,6 +447,8 @@
   [tableView layoutIfNeeded];
   
   [tableView endUpdatesAnimated:NO completion:^(BOOL completed) {
+    XCTAssertEqual(tableView.testDataController.numberOfAllNodesRelayouts, 1);
+
     for (int section = 0; section < NumberOfSections; section++) {
       for (int row = 0; row < NumberOfRowsPerSection; row++) {
         NSIndexPath *indexPath = [NSIndexPath indexPathForRow:row inSection:section];