在 Robolectric 测试中，UiDevice.getUiAutomation(instrumentation) 返回 null 导致 NPE

如何解决在 Robolectric 测试中，UiDevice.getUiAutomation(instrumentation) 返回 null 导致 NPE

在我的 Roblectric 测试中，我尝试使用 UiDevice

确认权限对话框

@RunWith(RobolectricTestRunner::class)
@Config(sdk = [Build.VERSION_CODES.P])
open class FooTest {

  @Before
  private fun before() {

    var device = UiDevice.getInstance(InstrumentationRegistry.getInstrumentation())

    // Confirm permissions dialog with device object
    // ...
  }

但是这一行抛出了一个 NPE 异常

var device = UiDevice.getInstance(InstrumentationRegistry.getInstrumentation())

带有堆栈跟踪

java.lang.NullPointerException
at androidx.test.uiautomator.QueryController.<init>(QueryController.java:95)
at androidx.test.uiautomator.UiDevice.<init>(UiDevice.java:109)
at androidx.test.uiautomator.UiDevice.getInstance(UiDevice.java:261)

因为 UiDevice.getUiAutomation(instrumentation) 返回 null

public QueryController(Instrumentation instrumentation) {
    mInstrumentation = instrumentation;
    UiDevice.getUiAutomation(instrumentation).setonAccessibilityEventListener(mEventListener);
}