gistfile1.m

//
//  KVOSampleTests.m
//  KVOSampleTests
//
//  Created by taiki on 2014/02/25.
//
//

#import <XCTest/XCTest.h>

@interface KVOSampleTests : XCTestCase
@property (strong, nonatomic) UIView *observee;
@end

@implementation KVOSampleTests

- (void)setUp
{
    [super setUp];
    _observee = UIView.new;
}

- (void)tearDown
{
    [super tearDown];
    _observee = nil;
}

- (void)testAddObserverManyTimes
{
    [_observee addObserver:self
                forKeyPath:@"frame"
                   options:NSKeyValueObservingOptionOld
                   context:NULL];
    [_observee addObserver:self
                forKeyPath:@"frame"
                   options:NSKeyValueObservingOptionOld
                   context:NULL];
    [_observee removeObserver:self forKeyPath:@"frame" context:NULL];
    [_observee removeObserver:self forKeyPath:@"frame" context:NULL]; // 取るとobserverが残ってるって怒られる
}

@end