DexIndexOverflowException Only When Running Tests

Question

I can successfully build and run my Android app in my debug and release variants with no problem. Yet, when I try to run my new unit tests (I never had them before), I get t

Answer 1

the error occurs maybe because of too many functions in your projects and library. You can:
- Enable multiple dex as @Intellij Amiya's answer
- Check libraries: specifying only the specific Google Play services APIs your app uses, instead of all of them.

compile 'com.google.android.gms:play-services-ads:7.5.0'

Find and exclude duplicated dependencies: open your terminal and run:

gradle -q dependencies

It will show a list as below example:

+--- com.android.support:appcompat-v7:23.0.1
|    \--- com.android.support:support-v4:23.0.1
|         \--- com.android.support:support-annotations:23.0.1
+--- :dputility_library-1.1.2:
+--- com.google.android.gms:play-services-ads:7.5.0
|    +--- com.google.android.gms:play-services-base:7.5.0
|    |    \--- com.android.support:support-v4:22.0.0 -> 23.0.1 (*)
|    \--- com.google.android.gms:play-services-analytics:7.5.0
|         \--- com.google.android.gms:play-services-base:7.5.0 (*)
+--- com.jakewharton:butterknife:7.0.1
+--- com.afollestad:material-dialogs:0.7.6.0
|    +--- com.android.support:support-v4:22.2.0 -> 23.0.1 (*)
|    +--- com.android.support:appcompat-v7:22.2.0 -> 23.0.1 (*)
|    +--- com.android.support:recyclerview-v7:22.2.0
|    |    +--- com.android.support:support-annotations:22.2.0 -> 23.0.1
|    |    \--- com.android.support:support-v4:22.2.0 -> 23.0.1 (*)
|    \--- com.android.support:support-annotations:22.2.0 -> 23.0.1

You can see some dependencies with (*), you can exclude it from your gradle dependences:

compile('com.google.android.gms:play-services-ads:7.5.0')
{
    exclude module: 'support-v4'
    exclude module: 'play-services-base'
}

Actually, for me, the excluding method works (multiple dex does not). Hope it helps.