Make Android Gradle display unit test failure messages

By default, Gradle does not show you what happened when a unit test failed:

$ ./gradlew test
...
MyTest > Black_is_white FAILED
    org.junit.ComparisonFailure at MyTest.java:6
    ^^^ WHAT ACTUALLY FAILED????
...

This is insane, and can be fixed (thanks to mrhaki) by editing build.gradle to add:

// NOTE: this is the non-Android solution - add to build.gradle
test {
    testLogging {
        exceptionFormat = 'full'
    }
}

The above doesn’t work with Android, but something similar does:

// Android solution: add this to app/build.gradle
android.testOptions.unitTests.all {
    testLogging {
        exceptionFormat = "full"
    }
}

And sanity prevails:

$ ./gradlew test
...
MyTest > Black_is_white FAILED
    org.junit.ComparisonFailure:
    expected:<[black]> but was:<[white]>
        at org.junit.Assert.assertEquals(Assert.java:115)
        at org.junit.Assert.assertEquals(Assert.java:144)
        at MyTest.Black_is_white(MyTest.java:6)
...

Files for plain Gradle:

$ cat build.gradle
apply plugin: 'java'

repositories {
    mavenCentral()
}
     
dependencies {
    testCompile 'junit:junit:[4,)'
}

test {
    testLogging {
        exceptionFormat = 'full'
    }
}

$ cat src/test/java/MyTest.java
public class MyTest
{
    @org.junit.Test
    public void Black_is_white()
    {
        org.junit.Assert.assertEquals("black", "white");
    }
}

Files for Android+Gradle

$ cat build.gradle
buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.1'
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

$ cat app/src/main/AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="net.artificialworlds.testapp">
</manifest>

$ cat app/src/test/java/MyTest.java
public class MyTest
{
    @org.junit.Test
    public void Black_is_white()
    {
        org.junit.Assert.assertEquals("black", "white");
    }
}

$ cat build.gradle
buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.1'
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

$ cat local.properties
sdk.dir=/home/andy/Android/Sdk

$ cat settings.gradle
include ':app'