Hey Phil! Loving you content, especially the testing series as a lot of job offers qant some experience in TDD and I didn't (or couldn't? haha) find any comprehensive, extensive testing tutorials for Android. Thank you! I just wanted to mention that we can speed up the tests by running them as local unit tests via a simulated device (not emulated) by using Robolectric. ^^ Keep up the good stuff!
Good day, please tell me at 3:13 you said that we add the @RunWith(AndroidJUnit4::class) annotation to indicate to Junit that these tests are instrumented. And then at 3:50 you said that the @SmallTest annotation is needed to show that unit tests are inside. Don't these two annotations contradict each other?
No, a unit test can be instrumented or local. Unit test just means it tests a single instance (class/function) in your code. Local and instrumented just mean it either runs on the jvm or an android device
I believe with suspend functions in your DAO, you don't need "allowMainThreadQueires", since Room will actually do the work on another thread, even if the coroutine from which you're calling it is currently executing on the main thread. Of course, you must be in a coroutine in order to call a suspend function, which is why it's recommended for Room DAO functions that don't return something observable (e.g. LiveData, as you pointed out).
Thanks so much for the content you are sharing. I am moving from React Native Development back to Android Development and your videos have been a great source for me to catch up with the latest technologies available. Also, as I was running the project (that I've downloaded from the GitHub link available on this video description), I faced an issue when trying to run the first test on my Mac M1. There is an incompatibility between the room version on your GitHub project and M1 Macs. This issues has been resolved on later version of room starting at 2.4.0
Also, in my experience, a new instance of your test class (e.g. "ShoppingDaoTest" in your example) is created to run each test case (function/method), and so I've had success just using "by lazy" to initialize things such as the DB, which is a bit simpler than "lateinit var" and an "@Before" method.
Lazy will keep the same reference throughout tests, while @Before creates a new one for each test. You don't want that a test case fails be aus a previous test manipulated a field lime the DB
@@PhilippLackner Thanks for your quick reply. I'm really curious now and would love to debug this with you if you're willing. Lazy will keep the DB around as long as the instance of the test class exists, and if the same instance of the test class were used to run more the one individual test, of course that would be bad because it would break isolation between the test cases. In pratice, however, I always find that Android Studio creates a new instance of the test class for each individual test case, even if I run them all together in one "batch". I've confirmed this by debugging. It's because of this behaviour that Lazy has worked just fine for me in practice. I'm really curious whether you see the same thing, or is it a quirk of my setup? Perhaps this behaviour isn't guaranteed, and perhaps that is the reason behind the best practice of assuming that the test class instance might be reused?
Now and then you learn something so good it just makes your hair stand on end, tingles of numbly in my flesh as I feel the power flow through my fingers... but it is so simple and kinda seemingly stupid, as in no big deal...Don't judge me. CTL + to see our available functions. YES!!! hahahaha Oh the testing is good too ;)
Hi, Philipp! I understand that @SmallTest is for Unit tests, but at the same time we are testing our database (DAO is part of that, right?). In the table at 4:23 it shows Database tests should use @MediumTest, so this got me a bit confused. Could you explain why @SmallTest for DAO interface testing?
We actually are not testing the database, but the Dao code. Database is used to refer to the persistent data storage. In tests we are using "in memory database" - which stores the data only in memory. (RAM). The data is not persisted once the test completes. Integration tests can use actual database if required.
Thank you very much! I am currently enrolled to Udacity Nanodegree and I find you videos more detailed for beginners it is very important! Subscribed :)
Well done brother, awesome video, I have just one question, what about foreign keys, when one entity requiers others entities to be populated. Should I put all code in one test class
Tests are design to check if our code has bugs. * Philipp Testing * Philipp : "Oh. We get an error here... Let's take a look in our test case; something must be wrong here"
bro just loving the series. But i have some queries. There's not even a single video in entire youtube about working with multiple table with room. Please can you create one very simple tutorial about that??
Can you please clarify why we didn't include a test case for observeAllShoppingItems while we did include a test case for observeTotalPrice, both of them returns live data?
This is unit test right? Why are logic and testClasses added to and "androidTest" folder. Shouldn't unit tests be in "android" folder and UI tests in "androidTest" folder.?
Hello. Thanks for this grate tutorial. Just there is one question for me: We shouldn't test every single code indivigualy? for find out easier witch part of code causing the error? Thanks in advance
When testing the insert function, what if the query function doesn't work as expected and so the test case fails. is there a way not to depend the test case of a function (insert function) on another function that we have written ourselves (query function)? This part seemed a bit strange to me.
I have a question, are those tests independent? We are testing our Insert function but we are calling observeAll function in the test, We are testing our Delete function, but we are calling insert and delete functions inside the test, etc. ?
In this simple example it probably doesn't make that much sense, but imagine you have complex sql queries and you want to test if your queries are correct and also if they still work as expected after changing them
@@PhilippLackner that makes much more sense. If you have custom queries - they have to be tested, because once you have to update the SQL - you can break something. Thanks!
Hi Philip, thanks for this course. But I have a question: what is the purpose of these tests you are writing in this specific video? I mean, what are you really testing? The functions you are testing are not even our functions, they are abstract and are implemented by Room, so what is exactly testing? The only thing I can suppose is that you are testing the query you wrote as annotations on top of dao functions, because maybe sometimes we can have complex queries, am I right? EDIT: just to be more clear, for example you are testing that insert a product insert really a product, but how is possible this cannot happens? In the end, this is done by Room, so of course it will be inserted...I hope you understand where is my doubt :D
Sure, this example here is super easy and wouldn't make sense in an actual more complex app. The point is just to show how it would work. For more complex queries and database flows it definitely makes sense to test that. It's not about testing if Room behaves right, but if you actually wrote your queries correctly.
I have a question. Why do we need to test database as it would be much simpler to open app inspection and see whats going on in the data base as we add or remote entity from mobile?
the run annotation indicates it is an integrated test and small test annotation indicates that it is a unit test. What kind of test is it? is it both at the same time?
I'm having an error while following the tutorial in my project. the difference I have is that I have an autoGenerated primary key field in my Entity. the error I'm getting is that the database does not contain the object that I put in it. the reason is that it generates the primary key than put it in the database. is there a way to make sure the objects are the same? thank you in advance.
@@SerhiiOr yes, but then you need sqlite installed on your pc. You shouldn't do that as I said because then you're using another sqlite version than on your android device
great vid. What exactly does 'get' before Rule annotation do ? Ok, i supposes its getting the rule :) but why is has to be there and not in others annotations?
i think to declare that instead of executing functions that performs asynchroniously ..use that rule object(to store the details of tasks who are running asynchroniously )to specify that functions should run in sequence because we are testing it in mainthread ..like write/update data then other methods like read and all that
16:51 how much is the RAM on your System ? my laptop has 4 GB and i don't think it will work for me since running an android emulator slows it down a lot. Can a physical device also work for these test cases ? ( My laptop does have Intel I5 - 10th gen with 1 TB HDD and 256 GB of SSD, still i think the 4 GB ram is costing me the emulator, your opinion on this please? )
In this simple case for demonstration it doesn't make much sense, but if you have complex queries, it makes sense to test if these are working as expected
Thanks for the example. But wouldn't testing a repository make more sense? Testing a DAO doesn't really seem necessary to me, it mainly tests room, and maybe your skill to write basic SQL queries xD.
Lmao, I saw this channel name and was about to inform you that someone was using your videos. Then I remembered how you made an entire video about changing your channel name.
Hi, does anyone have the LiveDataUtil class but in java ? I am kind of struggling with converting it. Yes I do java it is a requirement dont bite my head off for it :D
@@PhilippLackner I see, thanks! And thank you for the great content! (The reason to use Java is that I'm a beginner and have already tried to learn way too many languages this year... and btw, I think your pronunciation of kuh-routine is hilarious xD)
Thank you so much for this wonderful tutorial I have a problem with this episode I wrote the code and got this Error: java.lang.RuntimeException: cannot find implementation for com.application.unittest.data.local.ShoppingItemDatabase. ShoppingItemDatabase_Impl does not exist at androidx.room.Room.getGeneratedImplementation(Room.java:100) at androidx.room.RoomDatabase$Builder.build(RoomDatabase.java:1486) at com.application.unittest.data.local.ShoppingDaoTest.setup(ShoppingDaoTest.kt:38) I checked stackoverflow but those solutions didn't work for, so what should I do?
