使用ProGuard + Dagger时，Firebase测试实验室失败

当满足以下条件时，仪器测试确实可以在本地仿真器和物理设备上通过，但在Firebase测试实验室上则失败：

• ProGuard已启用调试版本；
• 同时存在Dagger和Espresso。

FTL显示不同的测试问题：

1）如果使用API​​ 26-28，则显示Instrumentation run failed due to 'java.lang.NoClassDefFoundError'或Instrumentation run failed due to 'Process crashed.'

异常stacktrace看起来像这样，它并不总是显示在Firebase中，而是总是出现在logcat中：

Rejecting re-init on previously-failed class java.lang.Class<androidx.test.espresso.core.internal.deps.dagger.internal.Factory>:
java.lang.NoClassDefFoundError: Failed resolution of: Ljavax/inject/Provider;

FATAL EXCEPTION: Instr: androidx.test.runner.AndroidJUnitRunner
Process: com.example.debug, PID: 11425
java.lang.NoClassDefFoundError: Failed resolution of: Ljavax/inject/Provider;
    at java.lang.Class.classForName(Native Method)
    at java.lang.Class.forName(Class.java:453)
    at androidx.test.internal.runner.TestLoader.doCreateRunner(TestLoader.java:72)
    at androidx.test.internal.runner.TestLoader.getRunnersFor(TestLoader.java:104)
    at androidx.test.internal.runner.TestRequestBuilder.build(TestRequestBuilder.java:789)
    at androidx.test.runner.AndroidJUnitRunner.buildRequest(AndroidJUnitRunner.java:544)
    at androidx.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:387)
    at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:2145)
Caused by: java.lang.ClassNotFoundException: Didn't find class "javax.inject.Provider" on path: DexPathList[[zip file "/system/framework/android.test.runner.jar", zip file "/system/framework/android.test.mock.jar", zip file "/data/app/com.example.debug.test-9kvw--JgNKzmuQurRdDbCQ==/base.apk", zip file "/data/app/com.example.debug-sz-oCUGs05zlEadCzyqsDA==/base.apk"],nativeLibraryDirectories=[/data/app/com.example.debug.test-9kvw--JgNKzmuQurRdDbCQ==/lib/arm64, /data/app/com.example.debug-sz-oCUGs05zlEadCzyqsDA==/lib/arm64, /system/lib64]]
    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:134)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
    ... 8 more

2）我还在API 21上运行了一项测试，该测试在日志中仅包含一个NoClassDefFoundError。但是，API 26-28上也存在此异常，但这是上面显示的异常的一部分。在不同的API级别上进行记录的方式可能只是有些差异。

java.lang.NoClassDefFoundError: androidx.test.espresso.core.internal.deps.dagger.internal.Factory

FATAL EXCEPTION: Instr: androidx.test.runner.AndroidJUnitRunner
Process: com.example.debug, PID: 5691
java.lang.NoClassDefFoundError: androidx.test.espresso.core.internal.deps.dagger.internal.Factory
    at java.lang.Class.classForName(Native Method)
    at java.lang.Class.forName(Class.java:308)
    at androidx.test.internal.runner.TestLoader.doCreateRunner(Unknown Source)
    at androidx.test.internal.runner.TestLoader.getRunnersFor(Unknown Source)
    at androidx.test.internal.runner.TestRequestBuilder.build(Unknown Source)
    at androidx.test.runner.AndroidJUnitRunner.buildRequest(Unknown Source)
    at androidx.test.runner.AndroidJUnitRunner.onStart(Unknown Source)
    at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1837)

来自build.gradle配置的一些相关行：

android {
  defaultConfig {
    testInstrumentationRunner 'androidx.test.runner.AndroidJUnitRunner'
  }

  buildTypes {
    debug {
      minifyEnabled true
      useProguard true
      proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules-debug.pro'
      testProguardFile 'proguard-rules-test.pro'
    }
  }
}

dependencies {
  testImplementation 'junit:junit:4.12'

  androidTestImplementation 'androidx.test:core:1.0.0-beta01'
  androidTestImplementation('androidx.test.espresso:espresso-core:3.1.0-beta01') {
    //  exclude module: 'javax.inject' - Exclusion doesn't help
  }
  // androidTestImplementation 'javax.inject:javax.inject:1' - Inclusion doesn't help either
  androidTestImplementation('androidx.test.ext:junit:1.0.0-beta01') {
    exclude group: "org.junit"
  }
  androidTestImplementation 'androidx.test:runner:1.1.0-beta01'
  androidTestImplementation 'androidx.test:rules:1.1.0-beta01'
  androidTestImplementation 'org.mockito:mockito-android:2.22.0'

  implementation 'com.google.dagger:dagger:2.16'
  kapt 'com.google.dagger:dagger-compiler:2.16'
}

proguard-rules-test.pro：

-ignorewarnings
-dontshrink
-dontoptimize
-dontobfuscate

禁用ProGuard或删除Dagger依赖性后，测试将开始通过FTL。