IssueTracker

Component used: androidx.media:media

Version used: 1.3.1 and 1.4.3

Devices/Android versions reproduced on: None - JUnit

In v1.3.1 of AndroidX Media, this change was introduced:

https://android.googlesource.com/platform/frameworks/support/+/25f9f769a5b0d47ffce6413a1b9a2311afc2ad4e%5E%21/

This static field was introduced into MediaSessionCompat:

public static final int PENDING_INTENT_FLAG_MUTABLE = Build.VERSION.CODENAME.equals("S") ? 0x02000000 : 0;

For reasons that are not immediately obvious, this has prevented normal mocking of the MediaSessionCompat class.

Frameworks such as Mockito presumably attempt to instantiate an empty version of the class via their bytecode mechanisms, and for JVM-related reasons, this has the consequence of initialising this static property. In the JUnit context, Build.VERSION returns null for all of its fields and therefore this causes a null pointer exception. It also cannot be conventionally set or mocked.

We currently have a workaround available to us, in the form of a test setter that uses reflection:

fun setFinalStaticFieldInTest(field: Field, newValue: Any?) {
    field.setAccessible(true)
    val modifiersField: Field = Field::class.java.getDeclaredField("modifiers")
    modifiersField.setAccessible(true)
    modifiersField.setInt(field, field.getModifiers() and Modifier.FINAL.inv())
    field.set(null, newValue)
}

and

setFinalStaticFieldInTest(Build.VERSION::class.java.getField("CODENAME"), "UNKNOWN")

However, as you might hope, this is flagged by the build process as a warning and ultimately due to be prohibited - therefore not a sustainable solution.

I realise that JUnit-based mocking of Android platform components is potentially fraught with difficulty and that we should not expect all of them to work seamlessly. However this did work and the approach taken here has broken it in a way that could probably be avoided.

Is it possible please to move this code back to an inline position in the constructor, or an instance method?