Robolectric / Mockito给出错误'when（）需要一个参数，该参数必须是'模拟的方法调用'，但它是一个模拟物

Question

实际上，问题比标题更奇怪。我有两个测试，但看不到它们之间的区别。在一个我做

when(context.getPackageManager()).thenReturn(packageManager);

并且工作正常。我在另一个地方做同样的事情，但出现错误。
这是成功的测试：
@RunWith(RobolectricTestRunner.class)

@@ LooperMode（LooperMode.Mode.PAUSED）@Config（sdk = Build.VERSION_CODES.P）公共类BtScannerMockTests{@规则公共MockitoRule mockitoRule = MockitoJUnit.rule（）。strictness（Strictness.LENIENT）;
@Mock
BluetoothAdapter bluetoothAdapter;
@Mock
BluetoothLeScanner bluetoothLeScanner;
@Mock
PackageManager packageManager;
@Mock
Context context;

@Before
public void setUp() throws Exception {
    ShadowLog.stream = System.out;
}

private void setUpMocksForAdapter()
{
    BtScanner.testBtleSupport = true;
    AndroidBtManager.setBluetoothAdpater(bluetoothAdapter);
    when(bluetoothAdapter.isEnabled()).thenReturn(true);
    when(bluetoothAdapter.getState()).thenReturn(BluetoothAdapter.STATE_ON);
    when(bluetoothAdapter.getBluetoothLeScanner()).thenReturn(bluetoothLeScanner);
    when(context.getPackageManager()).thenReturn(packageManager);
    when(packageManager.hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)).thenReturn(true);
}

private long startTime = 0;
private long time = 0;
private ScannerCountDownLatch countDownLatch;
private int btDiscoveryTime;
private int btleScanTime;

@Test
public void testBtScannerCycle_BtleScanlength() throws InterruptedException
{
    StatusEventCallback statusEventCallback = new StatusEventCallback()
    {
        @Override
        public void onStatusEvent(StatusEvent statusEvent, PhdInformation phdInformation)
        {
            System.out.println("Status event " + statusEvent.name());
            switch(statusEvent)
            {
                case BTLE_SCAN_STARTED:
                    startTime = System.currentTimeMillis();
                    break;
                case CLASSIC_SCAN_STARTED:
                    time = System.currentTimeMillis() - startTime - btleScanTime;
                    startTime = System.currentTimeMillis();
                    countDownLatch.countDown();
                    break;
            }
        }
    };
    btDiscoveryTime = 1000;
    btleScanTime = 10000;
    Context context = ApplicationProvider.getApplicationContext();
    setUpMocksForAdapter();
    AndroidBtManager.setStatusEventCallback(statusEventCallback);
    BtScanner.setScanTimes(btDiscoveryTime, btleScanTime);
    BtScanner btScanner = new BtScanner(context, bluetoothAdapter);
    startTime  = System.currentTimeMillis();
    countDownLatch = new ScannerCountDownLatch(2);
    btScanner.start();
    shadowOf(Looper.getMainLooper()).idle();
    if(countDownLatch.await(15, TimeUnit.SECONDS)) // Assert length of btle scan time 1
    {
        assertTrue((time > -50 && time < 50));
        countDownLatch = new ScannerCountDownLatch(1);
        if(countDownLatch.await(15, TimeUnit.SECONDS))  // Assert length of btle scan time 2
        {
            assertTrue((time > -50 && time < 50));
        }
        else // Timeout
        {
            fail();
        }
    }
    else  // Timeout
    {
        fail();
    }
    btScanner.terminateScan();
    assertFalse(btScanner.isBtScannerRunning());
}

测试有点复杂，但是重要的是在'setUpMocksForAdapter（）'中。它工作正常。失败的测试更加简单，因为它尚未完成并且还没有断言。
@RunWith(RobolectricTestRunner.class)
@LooperMode(LooperMode.Mode.PAUSED)
@Config(sdk = Build.VERSION_CODES.P)
public class ProprietaryDriverMonitorTests
{
@Rule
public MockitoRule mockitoRule = MockitoJUnit.rule().strictness(Strictness.LENIENT);
@Mock
Intent intent;
@Mock
ResolveInfo resolveInfo1;
@Mock
ResolveInfo resolveInfo2;
@Mock
PackageManager packageManager;
@Mock
Context context;

@Before
public void setUp() throws Exception {
    ShadowLog.stream = System.out;
    context = ApplicationProvider.getApplicationContext();
    ContinuaHandlerThread.isUnitTesting = true;
}

private List<ResolveInfo> matches = new ArrayList<>();

@Test
public void testBasicCycle() throws Exception
{
    setUp();
    matches.clear();
    matches.add(resolveInfo1);
    matches.add(resolveInfo2);
    when(context.getPackageManager()).thenReturn(packageManager);
    when(packageManager.queryIntentServices(intent, 0)).thenReturn(matches);
    //resolveInfo1.serviceInfo.packageName
    AndroidBtManager androidBtManager = new AndroidBtManager(context, false, false, true);
    ProprietaryDriverMonitor proprietaryDriverMonitor =
            new ProprietaryDriverMonitor(androidBtManager, context, 5);
    proprietaryDriverMonitor.start();
    Thread.sleep(20000);
}

[当我执行“（context.getPackageManager（））。thenReturn（packageManager）;时，此测试会给出失败信息我看不到为什么这个测试失败了，而另一个测试没有失败。我在测试2中做错了什么而在测试1中做错了吗？

Answer 1

我想带Robolectric的cks子不是热门话题。无论如何，答案都是该模拟（在这种情况下为Context）被生成该上下文的另一个调用覆盖。该上下文的初始Mock会保留下来，直到覆盖它的调用为止。在一个测试中，覆盖调用是在给定检查之前进行的，而在另一种情况下，则在之后进行。

在复杂的单元测试中很难看到，但是当涉及到蓝牙连接时，很难编写简单的单元测试。我发现无法测试某些功能，因为Android或库会覆盖我在测试过程中需要执行的任何Mock。