Which package for MultiDexTestRunner? android.support.multidex or com.android.test.runner

Question

The page http://developer.android.com/tools/building/multidex.html#testing advises

   dependencies {
     compile 'com.android.support:multidex:1.0.1'
     androidTestCompile 'com.android.support:multidex-instrumentation:1.0.1'
   }
   android {
     defaultConfig {
        multiDexEnabled true
        testInstrumentationRunner "android.support.multidex.MultiDexTestRunner"
     }
  }

But that produces a ClassNotFoundException when the tests are run.

The API documentation and dexdump show that there is com.android.test.runner.MultiDexTestRunner.

So if I disbelieve the documentation and instead specify

   dependencies {
     compile 'com.android.support:multidex:1.0.1'
     androidTestCompile 'com.android.support:multidex-instrumentation:1.0.1'
   }
  android {
     defaultConfig {
        multiDexEnabled true
        testInstrumentationRunner "com.android.test.runner.MultiDexTestRunner"
     }
   }

Then I get

com/company/myapp/MyApp; had used a different Landroid/support/multidex/MultiDexApplication; during pre-verification 
...
IllegalAccessExceptionIllegalAccessError: Class ref in pre-verified class resolved to unexpected implementation

I suspect that the doc page is wrong and the correct path is com.android.test.runner.MultiDexTestRunner ... plus I have some other issue.

Note the multidex application works fine. Somehow a second MultiDexApplication is included in the test apk.

Questions:
Which is the correct path for MultiDexTestRunner? Why am I getting a second MultiDexApplication in the test apk?

Answer 1

UPDATE: here's the fix. That's a common pattern, when you see such error message had used a different L<package>; during pre-verification, you need to exclude the package when running the test.

build.gradle

android {
    // ...
    defaultConfig {
        // ...
        multiDexEnabled true
        testInstrumentationRunner "com.android.test.runner.MultiDexTestRunner"
    }
}

dependencies {
    // ...
    // Need to exclude this when running test
    androidTestCompile('com.android.support:multidex-instrumentation:1.0.1') {
        exclude group: 'com.android.support', module: 'multidex'
    }
}

Application.java

public class Application extends android.app.Application {
    @Override
    protected void attachBaseContext(Context base) {
        super.attachBaseContext(base);
        MultiDex.install(this);
    }
}

Answer 2

Note: When you write instrumentation tests for multidex apps, no additional configuration is required if you use a MonitoringInstrumentation (or an AndroidJUnitRunner) instrumentation.

Thus, don't use MultiDexTestRunner, which is deprecated; use AndroidJUnitRunner instead. (This applies to multidex support library v1.0.2+)

android {
    // ...
    defaultConfig {
        // ...
        multiDexEnabled true
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
}

Only if you have a custom implementation of the test runner bootstrap with:

public void onCreate(Bundle arguments) {
  MultiDex.install(getTargetContext());
  super.onCreate(arguments);
  ...
}

See: https://developer.android.com/studio/build/multidex.html#testing