Question

我有一个需要序列化和反序列化的小型数据对象。可以说它被称为WeatherDetails，它看起来像这样：

WeatherDetails.h

@interface WeatherDetails : NSObject <NSCoding>
{
@private

@protected
}

#pragma mark - Properties

@property (nonatomic, copy) NSString *weatherCode;
@property (nonatomic, copy) NSString *weatherDescription;

@end

WeatherDetails.m

#import "WeatherDetails.h"

@implementation WeatherDetails

NSString *const WEATHER_DETAILS_WEATHER_CODE_KEY = @"s";
NSString *const WEATHER_DETAILS_WEATHER_DESCRIPTION_KEY = @"sT";

#pragma mark - Initialization, NSCoding and Dealloc

- (instancetype)initWithCoder:(NSCoder *)aDecoder
{
    self = [super init];

    _weatherCode = [aDecoder decodeObjectForKey:@"weatherCode"];
    _weatherDescription = [aDecoder decodeObjectForKey:@"weatherDescription"];

    return self;
}

- (void)encodeWithCoder:(NSCoder *)aCoder
{
    [aCoder encodeObject:_weatherCode forKey:@"weatherCode"];
    [aCoder encodeObject:_weatherDescription forKey:@"weatherDescription"];
}

目前我的测试看起来像这样;

#import <XCTest/XCTest.h>
#import <OCMock/OCMock.h>
#import "WeatherDetails.h"
@interface WeatherDetailsTests : XCTestCase

@end

@implementation WeatherDetailsTests

- (void)testThatWeatherCodeIsEncoded
{
    WeatherDetails *details = [[WeatherDetails alloc] init];
    [details setWeatherCode:@"A"];

    NSData *archive = [NSKeyedArchiver archivedDataWithRootObject:details];

    WeatherDetails *unarchive = [NSKeyedUnarchiver unarchiveObjectWithData:archive];

    XCTAssertEqualObjects(@"A", [unarchive weatherCode]);
}

- (void)testThatWeatherDescriptionIsEncoded
{
    WeatherDetails *details = [[WeatherDetails alloc] init];
    [details setWeatherDescription:@"A"];

    NSData *archive = [NSKeyedArchiver archivedDataWithRootObject:details];

    WeatherDetails *unarchive = [NSKeyedUnarchiver unarchiveObjectWithData:archive];

    XCTAssertEqualObjects(@"A", [unarchive weatherDescription]);
}

我有一种直觉，即如果所有属性都被正确编码，这种测试方法并不是最佳的，因为存在重复，但我无法想到更好的方法。有没有人对我提出改进的建议？

Answer 1

您真正想要测试的是在归档之前和之后对象是相同的。

在isEqual:中实施一种方法来比较对象（或覆盖- (BOOL)isEqualToWeatherDetails:(WeatherDetails *)details { if (![details isKindOfClass:[WeatherDetails class]]) return NO; return [self.weatherCode == details.weatherCode && self.weatherDescription isEqualToString:details.weatherDescription]; }）。

- (void)testNSCoder
{
    WeatherDetails *details = [[WeatherDetails alloc] init];
    [details setWeatherCode:@"A"];
    details.weatherDescription = @"Cloudy";

    NSData *archive = [NSKeyedArchiver archivedDataWithRootObject:details];

    WeatherDetails *unarchive = [NSKeyedUnarchiver unarchiveObjectWithData:archive];

    XCTAssertTrue([details isEqualToWeatherDetails:unarchive]);
}

然后你可以一次完成所有的平等比较：

isEqual:

如果你覆盖XCTAssertEqualObjects(details, unarchive);，那么你可以比较这样做：

isEqualToArray:

Apple倾向于添加其他方法（isEqualToDictionary:，isEqual:）。 Title由NSSet和NSDictionary等集合使用

Answer 2

最后，我通过应用custom assertion;

对其进行了改进

何时使用

只要满足以下任何条件，我们就应该考虑创建自定义断言：


我们发现自己在测试后的测试中编写（或克隆）相同的断言逻辑

我们发现自己在测试的结果验证部分编写了条件测试逻辑。也就是说，我们对Assertion方法的调用嵌入在if语句或循环中。

我们测试的结果验证部分遭受了模糊测试，因为我们在测试中使用了程序而不是声明性结果验证。

当断言失败时，我们发现自己正在进行频繁调试，因为它们没有提供足够的信息。

自定义断言目前看起来像这样：

/*!
 * @define XCTAssertEqualSerialized(value, object, selector)
 * Serializes (\a object), then desirializes it and compares result's property (\a propertyName) to (\a value) with XCTAssertEqualObjects
 * @param value Value to compare.
 * @param object Object to serialize.
 * @param selector Objects property to compare.
 */

#define XCTAssertEqualSerialized(value, object, selector) \
({ \
NSData *archived = [NSKeyedArchiver archivedDataWithRootObject:object]; \
NSObject *unarchived = [NSKeyedUnarchiver unarchiveObjectWithData:archived]; \
XCTAssertEqualObjects(value, [unarchived valueForKeyPath:NSStringFromSelector(selector)]); \
})

/*!
 * @define XCTAssertNotNilSerialized(object, selector)
 * Serializes (\a object), then desirializes it and checks result's property (\a propertyName) is not nil with XCTAssertNotNil
 * @param object Object to serialize.
 * @param selector Objects property to compare.
 */

#define XCTAssertNotNilSerialized(object, selector) \
({ \
NSData *archived = [NSKeyedArchiver archivedDataWithRootObject:object]; \
NSObject *unarchived = [NSKeyedUnarchiver unarchiveObjectWithData:archived]; \
XCTAssertNotNil([unarchived valueForKeyPath:NSStringFromSelector(selector)]); \
})

这导致测试看起来像这样：

- (void)testThatWeatherCodeIsEncoded
{
    WeatherDetails *details = [[WeatherDetails alloc] init];
    [details setWeatherCode:@"A"];

    XCTAssertEqualSerialized(@"A", details, @selector(weatherCode));
}

- (void)testThatWeatherDescriptionIsEncoded
{
    WeatherDetails *details = [[WeatherDetails alloc] init];
    [details setWeatherDescription:@"A"];

    XCTAssertEqualSerialized(@"A", details, @selector(weatherDescription));
}

如何测试实现NSCoding的简单数据对象类？

2 个答案: