AndroidSchedulers.mainThread() has Android dependencies in RxAndroid 2.0.0-RC2

[peter-tackage]

I've just started experimenting with RxJava/RxAndroid 2.0.0-RC2 on an Android app and when attempting to write a (JVM) unit test which replaces AndroidSchedulers.mainThread() with a Scheduler defined via RxAndroidPlugins it seems that this is not possible as it requires Android Handler and Looper dependencies.

This is the Exception that is reported when I attempt to execute the unit tests:

java.lang.ExceptionInInitializerError
    at <blah, blah>
Caused by: java.lang.RuntimeException: Method getMainLooper in android.os.Looper not mocked. See http://g.co/androidstudio/not-mocked for details.
    at android.os.Looper.getMainLooper(Looper.java)
    at io.reactivex.android.schedulers.AndroidSchedulers.<clinit>(AndroidSchedulers.java:24)
    ... 32 more

And this is the code in question from AndroidSchedulers in RxAndroid 2.0.0-RC2:

    // snip
    private static final Scheduler MAIN_THREAD = RxAndroidPlugins.initMainThreadScheduler(
        new HandlerScheduler(new Handler(Looper.getMainLooper())));

    /** A {@link Scheduler} which executes actions on the Android main thread. */
    public static Scheduler mainThread() {
        return RxAndroidPlugins.onMainThreadScheduler(MAIN_THREAD);
    }
    //snip 

Looking at the previous AndroidSchedulers definition from Rx 1.x, this was not the case as it would return the plugin's instance without attempting to evaluate the statement with Android dependencies on demand: the RxAndroidPlugins instance would take preference.

So a few questions. Is my evaluation correct or am I missing something? Secondly, is this the intended behavior?

[JakeWharton]

The behavior matches what RxJava 2 does for all of its schedulers which is supplying the original to the plugin functions.

We could change it to Function<Scheduler, Callable<Scheduler>> to lazy init. Wonder if RxJava would be interested in that API change as well.

[JakeWharton]

I've filed an issue on RxJava. We'll see what they say before taking any action here.