ActivityScenario.launch(TestActivity.class);
启动activity进行测试失败。错误堆栈如下：
java.lang.AssertionError: Activity never becomes requested state "[RESUMED, STARTED, CREATED, DESTROYED]" (last lifecycle transition = "PRE_ON_CREATE")
at androidx.test.core.app.ActivityScenario.waitForActivityToBecomeAnyOf(ActivityScenario.java:301)
at androidx.test.core.app.ActivityScenario.launchInternal(ActivityScenario.java:235)
at androidx.test.core.app.ActivityScenario.launch(ActivityScenario.java:190)
at com.dqs.shangri.testinstrumentation.ExampleInstrumentedTest.launchActivity(ExampleInstrumentedTest.java:46)
at java.lang.reflect.Method.invoke(Native Method)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at androidx.test.internal.runner.junit4.statement.RunBefores.evaluate(RunBefores.java:76)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at androidx.test.ext.junit.runners.AndroidJUnit4.run(AndroidJUnit4.java:104)
at org.junit.runners.Suite.runChild(Suite.java:128)
at org.junit.runners.Suite.runChild(Suite.java:27)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
at androidx.test.internal.runner.TestExecutor.execute(TestExecutor.java:56)
at androidx.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:392)
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:2089)
找了好久，最后才找到。
我的项目是升级到androidX，本以为是升级出错了。结果是我的项目通过反射设置了自己的Instrumentation，导致androidx一直没有拿到activity状态，最终超时报此错误。
看来androidx的是通过Instrumentation做了一些事情，先放在这里，后面会看一下androidx的实现原理。解决疑惑！
来源：CSDN
作者：ShangriDong
链接：https://blog.csdn.net/dongqiushan/article/details/104124585