Initial pass with diffing fixtures

SubspecWorkspaces/ASDKDiffing/ASDKDiffingTests/ASDKDiffingFixtures.m

@@ -0,0 +1,136 @@
+//
+//  ASDKDiffingFixtures.m
+//  ASDKDiffing
+//
+//  Created by Adlai Holler on 6/20/17.
+//
+//
+
+#import "ASDKDiffingFixtures.h"
+#import <AsyncDisplayKit/AsyncDisplayKit.h>
+#import <stdatomic.h>
+
+atomic_uint g_identifier;
+atomic_uint g_val;
+
+void ASTReset() {
+  atomic_store(&g_identifier, 0);
+  atomic_store(&g_val, 0);
+}
+
+NSInteger ASTNextIdentifier() {
+  return atomic_fetch_add(&g_identifier, 1);
+}
+
+NSInteger ASTNextContents() {
+  return atomic_fetch_add(&g_val, 1);
+}
+
+id ASTWithDebugNamesTable(id (NS_NOESCAPE ^block)(NSMapTable<NSNumber *, NSString *> *table)) {
+  static NSMapTable<NSNumber *, NSString *> *table;
+  static NSLock *lock;
+  static dispatch_once_t onceToken;
+  dispatch_once(&onceToken, ^{
+    table = [NSMapTable strongToStrongObjectsMapTable];
+    lock = [NSLock new];
+  });
+  
+  [lock lock];
+  id result = block(table);
+  [lock unlock];
+  return result;
+}
+
+@implementation ASTViewModel
+
+- (instancetype)init
+{
+  if (self = [super init]) {
+    _identifier = ASTNextIdentifier();
+    _contents = ASTNextContents();
+  }
+  return self;
+}
+
+- (instancetype)viewModelByUpdating
+{
+  ASTViewModel *vm = [[self class] alloc]; // No init. We control the values manually.
+  vm->_identifier = _identifier;
+  vm->_contents = ASTNextContents();
+  return vm;
+}
+
+- (NSString *)debugDescription
+{
+  return ASObjectDescriptionMake(self, [self propertiesForDebugDescription]);
+}
+
+- (void)setDebugName:(NSString *)debugName
+{
+  ASTWithDebugNamesTable(^id(NSMapTable<NSNumber *,NSString *> *table) {
+    [table setObject:[debugName copy] forKey:@(self.identifier)];
+    return nil;
+  });
+}
+
+- (NSString *)debugName
+{
+  return ASTWithDebugNamesTable(^id(NSMapTable<NSNumber *,NSString *> *table) {
+    return [table objectForKey:@(self.identifier)];
+  });
+}
+
+- (NSMutableArray<NSDictionary *> *)propertiesForDebugDescription
+{
+  __auto_type array = [NSMutableArray array];
+  NSString *name = self.debugName;
+  if (name.length > 0) {
+    [array addObject:@{ @"name": name }];
+  } else {
+    [array addObject:@{ @"id": @(self.identifier) }];
+  }
+  [array addObject:@{ @"contents": @(self.contents) }];
+  return array;
+}
+
++ (void)reset
+{
+  ASTReset();
+}
+
+#pragma mark - IGListDiffable
+
+- (BOOL)isEqualToDiffableObject:(id<IGListDiffable>)object
+{
+  ASTViewModel *vm = (ASTViewModel *)object;
+  NSParameterAssert([(id)object class] == [self class]);
+  NSParameterAssert(vm.identifier == self.identifier);
+  return vm.contents == self.contents;
+}
+
+- (id<NSObject>)diffIdentifier
+{
+  return @(self.identifier);
+}
+
+@end
+
+@implementation ASTSection
+@end
+
+@implementation ASTItem
+@end
+
+@implementation ASTSectionCtrl
+
+- (ASCellNodeBlock)nodeBlockForItemAtIndex:(NSInteger)index
+{
+  return ^{
+    return [ASTItemNode new];
+  };
+}
+
+@end
+@implementation ASTItemNode
+
+@end