RxJava has been gaining popularity in the past couple of years and today is widely adopted in the Android community. So much in fact that I can’t recall an Android developer interview in the past 3 years that doesn’t mention RxJava.
Here is a short list of the most common interview questions I have asked candidates (or been asked as an interviewee). Answers to all questions can be found further down.
Jacoco is a widely used library to measure test code-coverage in JVM-based projects. Setting it up for Android applications has a few quirks and having multiple flavours, using Kotlin and writing (some) tests in Robolectric makes it even tricker. There are already great tutorials in how to set it up, like THIS and THIS one. In this post however I’ll not only give you a ready solution, but share all details how I got to it – this way you’ll be able to adapt it in the best way for your project.
This is Part 2 of a short series about optimising your build speeds. If you haven’t already, please check out Part 1, which describes the different build caches you can use.
In this post, I’ll explain some other build properties you can tweak. Let’s start with the Gradle ones.
One of my last tasks @ASOS was to investigate the slow build speeds of the Android application. This post is part of a short series about how we approached the problem, what we tried and what we found out. To be clear, don’t expect miracles and ? here, but you’ll get a better understanding of what you can do to optimise your builds.
Ideally automated tests should be predictable, isolated and precise, allowing you to find an issue quickly. If these conditions are met, you’ll never have to change a test unless to accommodate a changed requirement. This sounds great on paper, but in practice we often forget the isolated bit and start testing multiple things in a single test. If abused, we’ll end up with tests that need updating all the time, causing developer frustration and wasting time.
One tool that can help with isolation of tests is using matchers. As the name suggests, matchers allow you to match an object agains certain conditions.
With the exponentially increasing usage of
Kotlin these days, many developers face the issue of how to test the newly created Kotlin classes. As we know all classes and methods are
final be default in Kotlin, unless specifically
Mockito, one of the most popular mocking libraries for Java projects, can’t easily mock
final classes. Since we don’t want to
open up everything just for testing purposes, we need another solution.
Hadi Hariri highlighted in his excellent blog post that Mockito version
2.1.0 and above can perform the magic of mocking
final classes. Since mocking is something used only in tests … and usually it just works, we’ve neglected Mockito and were still using a very outdated version (1.10.19) in our project. There were a few pain-points while updating to the latest one, so hopefully this post will save you some time when going through the same process.