android – Dagger Field Injection Testing

我正在使用Dagger 2,并且在为我的类实现测试时,在模块中生成单例提供程序时遇到一些问题.

class SomeContentProvider extends ContentProvider {

    // this should be normal foo if run by application, 
    // or mocked foo if run by tests
    @Inject Foo foo;

    public Provider() {
        Component.getComponent().inject(this);
    }
}

@Module
class ProviderModule {
    @Singleton
    @Provides
    Foo providesFoo() {
        returns new Foo();
    }
}

@Module
class ProviderTestModule {
    @Singleton
    @Provides
    Foo providesFoo() {
        returns Mockito.mock(Foo.class);
    }
}


public class SomeContentProviderTests extends InstrumentationTestCase {

    @Inject Foo foo; // this should be mocked Foo

    @Override
    public void setUp() throws Exception {
        super.setUp();

        MockitoAnnotations.initMocks(this);

        Component.getTestComponent().inject(this);
    }

    public void test1() {
        // needs new instance of Foo when test1 is run from SomeContentProvider
    }

    public void test2() {
        // needs another new instance of Foo when test2 is run from SomeContentProvider
    }
}

所以我有2个问题.

>我无法使用构造函数注入,因为ContentProvider具有默认构造函数. SomeContentProvider如何从测试模块中获取Foo?
>在test1和test2中,如何确保在运行每个测试时创建新的Foo实例?

谢谢!

最佳答案 我发现这篇文章对我特别有用.虽然我遇到的特殊问题更加复杂 – 但我使用相同的想法来模拟模块的提供者.

How do you override a module/dependency in a unit test with Dagger 2.0?

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