IllegalAccessError 与 CountingIdlingResource

Question

该应用包含一个短暂显示的初始屏幕，并且该活动正在使用 IdlingResource 进行插桩测试，以便测试知道何时关闭初始屏幕。问题在于，在运行 API 19 的设备上进行测试期间，SplashActivity 会抛出看起来与依赖相关的异常：

import android.support.test.espresso.idling.CountingIdlingResource;
...
private CountingIdlingResource espressoTestIdlingResource =
new CountingIdlingResource("Splash_Delay"); // <-- Exception here line 22
...

app/build.gradle：

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
        exclude group: 'com.google.code.findbugs'
        exclude module: 'espresso-idling-resource'
        exclude group: "javax.inject"
    })
    compile 'com.android.support.test.espresso:espresso-idling-resource:2.2.2'

    compile 'com.google.dagger:dagger:2.10'
    annotationProcessor 'com.google.dagger:dagger-compiler:2.10'
    compile 'com.google.dagger:dagger-android:2.10'
    compile 'com.google.dagger:dagger-android-support:2.10'
    annotationProcessor 'com.google.dagger:dagger-android-processor:2.10'

    compile "com.android.support:appcompat-v7:$supportLibraryVersion"
    compile "com.android.support:design:$supportLibraryVersion"
    compile "com.android.support.constraint:constraint-layout:1.0.2"

    compile "com.jakewharton.timber:timber:4.5.1"
    compile "com.squareup.phrase:phrase:1.1.0"
    compile "com.squareup.retrofit2:retrofit:2.2.0"
    compile "com.squareup.retrofit2:converter-gson:2.2.0"
    compile "com.squareup.okhttp3:logging-interceptor:3.7.0"
    compile 'net.danlew:android.joda:2.9.9'

    testCompile 'junit:junit:4.12'
    compile 'com.google.firebase:firebase-crash:10.2.4'
    androidTestCompile 'junit:junit:4.12'
}

例外：

java.lang.IllegalAccessError
java.lang.IllegalAccessError: Class ref in pre-verified class resolved to unexpected implementation
    at com.myapp.android.ui.splash.SplashActivity.<init>(SplashActivity.java:22)
    at java.lang.Class.newInstanceImpl(Native Method)
    at java.lang.Class.newInstance(Class.java:1208)
    at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2101)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
    at android.app.ActivityThread.accessX800(ActivityThread.java:135)
    at android.app.ActivityThreadXH.handleMessage(ActivityThread.java:1196)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:136)
    at android.app.ActivityThread.main(ActivityThread.java:5001)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:515)
    at com.android.internal.os.ZygoteInitXMethodAndArgsCaller.run(ZygoteInit.java:785)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
    at dalvik.system.NativeStart.main(Native Method)

异常发生在 Firebase 测试实验室的 API 级别 19 Nexus 4 物理设备上。它不会出现在我们正在测试的任何其他平台上，包括本地 API 19 模拟 Nexus S。

我理解异常意味着存在模棱两可/重复（传递）依赖项，但我在 gradlew 依赖项中看不到任何依赖项，只有 Espresso Idling Resources v2.2.2。依赖项是“编译”而不是“androidTestCompile”，因为 Activity 中引用了 CountingIdlingResource。

如何确定原因并解决？

更新：Nexus 5 和 Nexus 7 上的 API 19 也会发生异常。以下是与空闲资源库相关的“./gradlew dependencies”输出部分：

_debugApk - ## Internal use, do not manually configure ##
+--- com.android.support.test.espresso:espresso-idling-resource:2.2.2
+--- com.google.dagger:dagger:2.10
...
_debugCompile - ## Internal use, do not manually configure ##
+--- com.android.support.test.espresso:espresso-idling-resource:2.2.2
+--- com.google.dagger:dagger:2.10
...
_releaseApk - ## Internal use, do not manually configure ##
+--- com.android.support.test.espresso:espresso-idling-resource:2.2.2
+--- com.google.dagger:dagger:2.10
...
_releaseCompile - ## Internal use, do not manually configure ##
+--- com.android.support.test.espresso:espresso-idling-resource:2.2.2
+--- com.google.dagger:dagger:2.10
...
compile - Classpath for compiling the main sources.
+--- com.android.support.test.espresso:espresso-idling-resource:2.2.2
+--- com.google.dagger:dagger:2.10

Answer 1

据我了解Google Samples 依赖：

com.android.support.test.espresso:espresso-idling-resource:2.2.2

仅在您实现自定义IdlingResource 时才需要。甚至在IdlingResourceSampleREADME中也有一句话：

考虑使用 espresso-contrib 包中的 CountingIdlingResource 类

据我了解，您正在尝试使用 espresso-contrib 包中的 CountingIdlingResource 代码，因此请尝试按照其他 Google sample 中编写的方式组织您的测试依赖项。