Question

我有一个Kiwi spec文件，看起来像这样：

#import "Kiwi.h"
#import "MyCollection.h"

SPEC_BEGIN(CollectionSpec)

describe(@"Collection starting with no objects", ^{
    MyCollection *collection = [MyCollection new];

    context(@"then adding 1 object", ^{
        MyObject *object = [MyObject new];
        [collection addObject:object];
        it(@"has 1 object", ^{
            [collection shouldNotBeNil];
            [collection.objects shouldNotBeNil];
            [[theValue(collection.objects.count) should] equal:theValue(1)]; //failing test
        });

        context(@"then removing 1 object", ^{
            [collection removeObject:object];
            it(@"has 0 objects", ^{
                [[theValue(collection.objects.count) should] equal:theValue(0)]; //passing test
            });
        });
    });
});

SPEC_END

运行规范导致此代码行[[theValue(collection.objects.count) should] equal:theValue(1)];

出现一次失败

这是奇怪的部分 - 如果我从规范中移除整个context(@"then removing 1 object", ^{...})块，则上述测试通过。

这让我相信在失败的测试之前[collection removeObject:object]行正在执行。我有一种感觉，我可能会误解执行块的顺序。

任何建议都将不胜感激！

Answer 1

你是正确的，[collection removeObject:object]在失败的测试之前被执行。将Kiwi测试视为两次通过：

设置：测试文件中的代码从上到下执行以设置测试上下文和期望
执行：每个单元测试运行，基本上每it / specify个语句运行一次，并为每个测试重复正确的设置/拆卸代码

请注意，Kiwi测试文件中的大多数代码都被指定为发送到Kiwi函数的一系列块。任何不遵循Kiwi块模式的代码，例如初始化/修改collection变量的代码，都可能因此在意外时间执行。在这种情况下，所有的集合修改代码都是在设置测试时第一次执行时执行的，然后运行测试。

解决方案

使用collection修饰符声明__block，并使用beforeEach来实例化和修改collection对象：

describe(@"Collection starting with no objects", ^{
    __block MyCollection *collection;
    beforeEach(^{
        collection = [MyCollection new];
    });

    context(@"then adding 1 object", ^{
        beforeEach(^{
            MyObject *object = [MyObject new];
            [collection addObject:object];
        });
        it(@"has 1 object", ^{
            ...
        });

        context(@"then removing 1 object", ^{
            beforeEach(^{
                [collection removeObject:object];
            });
            it(@"has 0 objects", ^{
                ...

beforeEach块告诉Kiwi每单元测试专门运行给定代码一次，并且对于嵌套上下文，块将根据需要按顺序执行。所以Kiwi会做这样的事情：

// run beforeEach "Collection starting with no objects"
collection = [MyCollection new]
// run beforeEach "then adding 1 object"
MyObject *object = [MyObject new]
[collection addObject:object]
// execute test "has 1 object"
[collection shouldNotBeNil]
[collection.objects shouldNotBeNil]
[[theValue(collection.objects.count) should] equal:theValue(1)]

// run beforeEach "Collection starting with no objects"
collection = [MyCollection new]
// run beforeEach "then adding 1 object"
MyObject *object = [MyObject new]
[collection addObject:object]
// run beforeEach "then removing 1 object"
[collection removeObject:object]
// execute test "has 0 objects"
[[theValue(collection.objects.count) should] equal:theValue(0)]

__block修饰符将确保通过所有这些块函数正确保留和修改collection对象引用。

Kiwi iOS上下文块的奇怪排序

1 个答案:

解决方案