How to test Jetpack Compose? - android

I use the new Jetpack Compose, now comes time to test UI. Does anyone know the tools for testing it?
Since Espresso mainly relies on view I don't think that it can help.

Android has a code sample (Jetnews) that includes a couple of UI tests. This may help you to set up some tests or in the future, they may add additional code samples around UI testing.
Edit: Link to Jetnews UI Tests

In goo.gle/compose-testing you'll find the official documentation.
Most of the official code samples have UI tests. Apart from the common UI checks in JetNews, you can find animation+screenshot tests in Rally, Interop tests in Crane, screen recreation and navigation tests in Jetchat, etc.

Related

How to retroactively add tests to a code base?

Suppose you are tasked with adding a testing framework to an existing code base that has very very little unit testing coverage. The code base isn't insanely large yet, however, it does have areas where it's not super clean, or not very OOP or testable.
I've read a couple of good answers:
Adding unit tests to legacy code
How to approach unit testing in a large project
Best Option for Retrospective application of TDD into C# codebase
But the project I'm working on is an Android app, so it's slightly different (given lots more UI components).
I have some questions that all relate to the same issue:
What's the best way to do go back and put a bunch of tests in place?
How do I prioritize which parts to test first?
do I start with areas where it's getting called a lot (and is there a tool for code analysis like this)?
or do I go back and look at classes which in the past have had the most number of bugs?
Should I write integration tests first (given this is an Android app and also integration tests may prevent broken unit tests/refactorings) and then work in the unit tests?
Sorry for all the questions, just really looking for a good approach, more specifically geared towards retrospectively testing an Android app.
P.S. I'm curious if people know of good tools they can use for code analysis that can help bring to attention the areas in a code base in which unit testing would be most helpful.
Usually when starting with unit testing on an existing application you would want to do it iteratively - you probably do not have the time or the man power for a big upfront investment and so you want to add unit tests as part of the required work:
Write unt tests When adding a new feature - or better yet use TDD
When fixing a bug - write unit test(s) that fails de to the bug before fixing it
When refactoring old code wriute unit tests to make sure no regression bus were introduced
Id the whole team follow the three steps above in a matter of weeks you should have good coverage for the code you've been changing - depending on the size of the project.
I don't have an Android-specific answer. I hope someone comes along and adds a good one. Meanwhile: write acceptance (integration) tests for your most important features (from your product owner's point of view, not from some tool's). You'll get the most coverage for your effort, and be the most likely to prevent bugs that customers care about. Don't worry so much about unit tests; those are for details.
[That's the answer given in the third post you cite, but we're still waiting for that Android-savvy answer so let's not call this a duplicate yet.]
Do write acceptance tests and, as necessary, unit tests for new features, and write unit tests when fixing bugs.
Regarding how to find areas of the code that need tests, the first thing to do is measure code coverage. (You can do that in the Android SDK with ant emma debug install test.) Obviously code with no coverage needs tests.

Test Driven Development For Android

Can we use JUnit for test driven development in Android ? If not, is there an alternative similar to JUnit ?
I searched a bit on google and also read a SO post Android Test Driven Development
It looks like Android was never made with TDD in mind. I wanted to be sure before I begin learning TDD and doing Android development at the same time.
I think you can completely rely on Robolectric for running your tests in JVM. You get to use JUnit4 for testing your POJOs and Robolectric provides you the support for testing the Android components.
I am also a beginner in TDD for Android Development. I find Robolectric really useful for test driving my code.
This video will tell you almost everything it provides you for unit testing the Android code.
UPDATE:
With the Android studio support and the new Android ecosystem, now unit testing can be done as a first class practice. Refer http://developer.android.com/training/testing/unit-testing/local-unit-tests.html for more details.
There are couple of good approaches to test drive the android code. The most effective ones I have found so far is using MVVM(model-view-viewmodel) or MVP(model-view-presenter) approach, where the business logic as well as presentation logic is decoupled from the view and can be easily be unit tested.
Yeah we can use JUnit for test driven development. To initiate with you can refer to following
link : http://developer.android.com/tools/testing/testing_android.html#JUnit
Following the documentation we can use the junit.framework to have unit testing done.
Here is a bit of explanation of the problem space: http://www.techwell.com/2013/04/applying-test-driven-development-android-development
The conclusion is you should use Robolectric. Unfortunately Robolectric is slow, and if you follow TDD even on a pragmatic level, you will end up with a couple of hundreds of test, that will run for couple of 10 seconds. And that is not you want to do with TDD. TDD test package should run at most in seconds.
My advise is:
Create wrapper classes around Android classes that simply call the Android class.
Write your app logic in pure Java.
Use Junit (or TestNG or whatever pleases you) to test you model/business logic
Use occasionally Robolectric for the wrapper classes (probably you won't have to use)
(You can write integration tests that use multiple classes, Robolectric, etc. but only run it on a separate Continous Integration server eg. hourly)
With this approach your logic will be more portable as well.

AndroidAnnotations and Unit Testing

I am using AndroidAnnotations(2.5) in a sample project I am currently working on.
Since you can annotate your classes with for example #EActivity,#ViewById,#Click which will all lead to generated compile-time code, I was wondering how one would go about creating unit tests / functional tests for any Android Annotations powered application.
I would love to hear some opinions on this matter.
Cheers,
I responded to a similar post here.
There are a couple of options available to you. You can, of course, test your code pre-generation in, what I claim, is a more unit testing style. This should test the Java code in isolation, preferably without generated code involved.
You can also test the code post-generation. The MyActivity_ classes generated by AA can be instantiated directly after compile time and test them accordingly. I claim this is edging towards an integration testing style.
While, I think it is always better to test than not to test, I think for integration tests, you should test on the hardware in a situation similar to production. This gives you a total picture of how your application will behave in a real world situation. Thus, for integration tests I prefer high level "is everything working well together" tests.
Robolectric and Robotium can help greatly in these two efforts. Robolectric allows you to instantiate you Activities in a unit test, while Robotium allows you to test selenium style directly on a device.
To recap, I prefer to heavily unit test my code without generation then do some light integration testing to make sure everything is working well together.

What is the best and easy tool to unit test Android apps?

I have been developing Android application for a small company and during the development process we need to do repetitive testing of some modules, So i searched tools for doing automation testing (unit testing) of the app. Android has a unit test tool however to write those test cases will itself take more time then to actually test it by hand.
I found some apps which do some great stuff and provide good charts for example Robolectric, robotium, fonemonkey4android, but am confused to what to be used, any one with any experience with the same can help.
I checked for previous questions on the similar terms like below
https://stackoverflow.com/questions/522312/best-practices-for-unit-testing-android-apps
But all the threads are very old and not so informative to decide on which to choose..
I think first you need figure out which part of your code you want to test.
For codes which doesn't related to user interface, you can test them with Robolectric. With Robolectric, the unit test code is the same to those written for java application. But it's not suitable for test ui components.
If you want to test ui, then you can choose robotium. But i always doubt whether it's worth writing tests for ui, they change too often..

How to test a project using instrumentation test in android

I want to test my project using an instrumentation test. I am a beginner at this.
Can anybody provide a basic tutorial for this?
Robotium is a great tool for testing Android app's you should take a look at it and it's very easy to use.
http://code.google.com/p/robotium/
To use ActivityInstrumentationTestCase2 we can create a wrapper over it. In order to do so you can try out example that this blog talks about.
testing Activities in simple way
The idea used is to take out common code in wrapper called BaseActivityTest so that while testing you just need to do minimum steps, and your activity gets tested too.

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