Hacking your keyboard with karabiner

Update

I’ve since come up with an easier way to maintain my rules. This post talks of some of the cool things you can do with Karabiner. But if you want a more maintainable way of customizing all this, read my other post instead.

tl;dr:

brew install yqrashawn/goku/goku
mkdir -p ~/.config && cd ~/.config
touch karabiner/karabiner.json
touch karabiner.edn
# update your edn file with a sample from here https://github.com/yqrashawn/GokuRakuJoudo/blob/master/tutorial.md
# or mine: https://gist.github.com/kaushikgopal/ff7a92bbc887e59699c804b59074a126
goku

Background #

I’ve been messing with mechanical keyboards recently.¹ There was one in particular which is a 60% layout that I fell in love with.

assertLastValue for RxJava TestObservers

The TestObserver is an RxJava staple for testing.

It allows you to assert values in a stream, in the specific order they were emitted. Here’s a quick code snippet from the movies-usf repository ¹:

@Test
fun onSearchingForMovieBladeRunner_shouldSeeSearchResult() {
    viewModel = MSMainVm(mockApp, mockMovieRepo)
    val viewStateTester = viewModel.viewState.test()

    viewModel.processInput(SearchMovieEvent("blade runner 2049"))

    viewStateTester.assertValueAt(1) {
        assertThat(it.searchedMovieTitle).isEqualTo("Searching Movie...")
        true
    }

    viewStateTester.assertValueAt(2) {
        assertThat(it.searchedMovieTitle).isEqualTo("Blade Runner 2049")
        // ...
        true
    }
}

If you look at the source for the base TestObserver, there are a bunch of these useful methods:

RxJava Tip for the Day - Share, Publish, Refcount and All That Jazz

Ok, so in my previous post I innocuously introduced the .share() operator.

Observable<Object> tapEventEmitter = _rxBus.toObserverable().share();

The .share() operator is basically just a wrapper to the chained call .publish().refcount().

You’ll find the chained combo .publish().refcount() used in quite a few Rx examples on the web. It allows you to “share” the emission of the stream. Considering how powerpacked and frequently used this combo is, RxJava basically introduced the friendlier more useful operator share(). This mechanism is sometimes referred to as “multicasting”.

#2026

#2025

#2024

#2023

#2022

#2020

#2019

#2018

#2015

#2012