FindfragmentByTag的单元测试条件

Question

Android Studio 3.2 Canary 2
Build #AI-173.4591728, built on February 8, 2018
JRE: 1.8.0_152-release-1024-b01 amd64
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
Linux 4.14.18-300.fc27.x86_64

我有以下活动，我想单位测试片段已经连接并应返回非编号的情况。并且应该陷入其他条件：

这是我的活动：

public class BillingActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.billing_container);
        if(getSupportFragmentManager().findFragmentByTag(BillingView.TAG) == null) {
            final FragmentTransaction fragmentTransaction =
                    getSupportFragmentManager().beginTransaction();
            fragmentTransaction.add(
                    R.id.billing_view_container,
                    BillingView.newInstance(),
                    BillingView.TAG);
            fragmentTransaction.commit();
        }
        else {
            Timber.d("Fragment already attached");
        }
    }
}

测试类是：我可以编写测试以附加片段，但是我想在片段已经连接并应返回非null时测试条件。

class BillingActivityTest: BaseRobolectricTestRunner() {
    private lateinit var billingActivity: BillingActivity
    @Before
    fun setup() {
        billingActivity = Robolectric.buildActivity(BillingActivity::class.java)
                .create()
                .start()
                .get()
    }
    @Test
    fun testBillingActivityIsNotNullValue() {
        assertThat(billingActivity, `is`(notNullValue()))
    }
    @Test
    fun testBillingFragmentHasStarted() {
        val actualFragment = billingActivity
                .supportFragmentManager
                .findFragmentByTag(BillingView.TAG)
        assertThat(actualFragment.tag, `is`(BillingView.TAG))
    }
    @Test
    fun testBillingFragmentAlreadyAttached() {
        /* how to test */
    }
}

感谢您的任何建议，

Answer 1

您选择的方法(使用recreate()(将起作用，只要它复制您的请求行为即可。我相信这是那里最短的方法。

尽管如此，我不能认为它是纯粹的单元测试，因为实际上您在作弊，因为显然您对活动的recreate()动作不感兴趣(这也可能带有副作用(。

如果您想执行纯单元测试，那么这是这样做的方法。宣布活动后：

    class MainActivity : AppCompatActivity() {
        internal var fragmentManagerRetriever = FragmentManagerRetriever()
        override fun onCreate(savedInstanceState: Bundle?) {
            super.onCreate(savedInstanceState)
            setContentView(R.layout.activity_main)
            val fragmentManager = fragmentManagerRetriever.getFragmentManager(this)
            if (fragmentManager.findFragmentByTag("TAG") == null) {
                val fragmentTransaction = fragmentManager.beginTransaction()
                fragmentTransaction.add(SomeFragment(), "TAG")
                fragmentTransaction.commit()
            }
        }
    }

其中FragmentManagerRetriever与此一样简单：

    class FragmentManagerRetriever {
        public FragmentManager getFragmentManager(FragmentActivity activity) {
            return activity.getSupportFragmentManager();
        }
    }

然后您有一个接缝进行纯单元测试：

    @Test
    fun nullCase() {
        val activityController = Robolectric.buildActivity(MainActivity::class.java)
        val activity = activityController.get()
        val fragmentManagerRetriever = mock(FragmentManagerRetriever::class.java)
        val fragmentManager = mock(FragmentManager::class.java)
        val fragmentTransaction = mock(FragmentTransaction::class.java)
        activity.fragmentManagerRetriever = fragmentManagerRetriever
        `when`(fragmentManagerRetriever.getFragmentManager(activity)).thenReturn(fragmentManager)
        `when`(fragmentManager.findFragmentByTag("TAG")).thenReturn(null)
        `when`(fragmentManager.beginTransaction()).thenReturn(fragmentTransaction)
        activityController.create()
        val inOrder = Mockito.inOrder(fragmentTransaction)
        inOrder.verify(fragmentTransaction).add(ArgumentMatchers.any(SomeFragment::class.java), ArgumentMatchers.eq("TAG"))
        inOrder.verify(fragmentTransaction).commit()
    }

和非挂钩情况的测试：

    @Test
    fun nonNullCase() {
        val activityController = Robolectric.buildActivity(MainActivity::class.java)
        val activity = activityController.get()
        val fragmentManagerRetriever = mock(FragmentManagerRetriever::class.java)
        val fragmentManager = mock(FragmentManager::class.java)
        val fragmentTransaction = mock(FragmentTransaction::class.java)
        activity.fragmentManagerRetriever = fragmentManagerRetriever
        `when`(fragmentManagerRetriever.getFragmentManager(activity)).thenReturn(fragmentManager)
        `when`(fragmentManager.findFragmentByTag("TAG")).thenReturn(mock(Fragment::class.java))
        activityController.create()
        verifyZeroInteractions(fragmentTransaction)
    }

Answer 2

我设法通过称为activity.recreate((

来做到这一点

@Test
fun testBillingFragmentAlreadyAttached() {
     billingActivity.recreate()
     val actualFragment = billingActivity
            .supportFragmentManager
            .findFragmentByTag(BillingView.TAG)
     assertThat(actualFragment.tag, `is`(BillingView.TAG))
}

但是，如果有人有更好的方法。很高兴听到另一个解决方案。