I'm trying to add some android native unit tests for a capacitor plugin I created.
The problem is that the method expects to get a PluginCall object as a param. In iOS it's pretty straightforward. for example:
func test()
{
let data = "madness? THIS. IS. DATA!!!!! ~Leonidas I, King of Data, around 480 BCE"
let plugin = Plugin()
let call = CAPPluginCall(callbackId: "test", options: [
"data": data
], success: { (result, call) in
let resultValue = result?.data["data"] as? Data
XCTAssert(resultValue != nil)
}, error: { (err) in
XCTFail("Error shouldn't have been called")
})
plugin.doSomethingCool(call!)
}
Pretty simple stuff really.
Trying to do the same thing for android, doesn't work quite well.
To instantiate a new PluginCall object I have to pass to the constructor a MessageHandler object, and to instantiate a MessageHandler object I have to pass a Bridge object, to instantiate a bridge object, I have to pass a PluginManager object that the compiler doesn't even recognise. Apparently an impossible task.
Of course I can always just replace the PluginCall param with the actual data, but I want to have a full test coverage for my plugin and not omit huge parts of it just so I can test it. Trying to search this problem online yielded no results, even the official docs doesn't say anything about it, so I turn to SO. Has anyone done something like this before and can point me in the right direction?
TL;DR
How can I create android native unit tests for a capacitor plugin?
Thanks :)
Related
I'm just trying to get started with Android development and Kotlin using Jetpack Compose. Note that, I'm a Kotlin novice, so I'm trying to learn along the way. I come from JavaScript/TypeScript background, so I'm trying to learn by thinking in JavaScript terms and implement in Kotlin terms by searching online.
I'm trying to list all installed applications on the device. While the app was working as expected up till now, I needed to add a feature to sort the installed app names. I referred to: https://www.bezkoder.com/kotlin-sort-list-objects/#Create_Class_for_handling_sorting. As soon as I added a custom class to sort the List<ApplicationInfo>, my app stopped building.
I have included my repo here: https://github.com/Hrishikesh-K/TryKotlin
If I comment these lines and this line as well, the app builds fine. With the current setup, I get an error:
Functions which invoke #Composable functions must be marked with the #Composable annotation
which points to line 21, character 18, which is the start of the word compare.
I don't understand why Compose would care about a custom class, it's not a Composable function after all. What am I missing?
In the compare method you are using LocalContext.current
override fun compare(o1 : ApplicationInfo, o2 : ApplicationInfo): Int {
return o1.loadLabel(LocalContext.current.packageManager).toString().compareTo(o2.loadLabel(LocalContext.current.packageManager).toString())
}
You can't use a #Composable functions if the method is not marked with the #Composable.
Use something different like:
data class CompareApplicationNames(val context: Context) : Comparator<ApplicationInfo> {
override fun compare(o1 : ApplicationInfo, o2 : ApplicationInfo): Int {
return o1.loadLabel(context.packageManager).toString().compareTo(o2.loadLabel(context.packageManager).toString())
}
}
Then just use:
Log.d("sorted:", listOfApplications.sortedWith(CompareApplicationNames(LocalContext.current)).toString())
I'm trying to learn the Arrow library and improve my functional programming by transitioning some of my Android Kotlin code from more imperative style to functional style. I've been doing a type of MVI programming in the application to make testing simpler.
"Traditional" Method
ViewModel
My view model has a LiveData of the view's state plus a public method to pass user interactions from the view to the viewmodel so the view model can update state in whatever way is appropriate.
class MyViewModel: ViewModel() {
val state = MutableLiveData(MyViewState()) // MyViewState is a data class with relevant data
fun instruct(intent: MyIntent) { // MyIntent is a sealed class of data classes representing user interactions
return when(intent) {
is FirstIntent -> return viewModelScope.launch(Dispatchers.IO) {
val result = myRoomRepository.suspendFunctionManipulatingDatabase(intent.myVal)
updateStateWithResult(result)
}.run { Unit }
is SecondIntent -> return updateStateWithResult(intent.myVal)
}
}
}
Activity
The Activity subscribes to the LiveData and, on changes to state, it runs a render function using the state. The activity also passes user interactions to the view model as intents (not to be confused with Android's Intent class).
class MyActivity: AppCompatActivity() {
private val viewModel = MyViewModel()
override fun onCreateView() {
viewModel.state.observe(this, Observer { render(it) })
myWidget.onClickObserver = {
viewModel.instruct(someIntent)
}
}
private fun render(state: MyViewState) { /* update view with state */ }
}
Arrow.IO Functional Programming
I'm having trouble finding examples that aren't way over my head using Arrow's IO monad to make impure functions with side effects obvious and unit-testable.
View Model
So far I have turned my view model into:
class MyViewModel: ViewModel() {
// ...
fun instruct(intent: MyIntent): IO<Unit> {
return when(intent) {
is FirstIntent -> IO.fx {
val (result) = effect { myRoomRepository.suspendFunctionManipulatingDatabase(intent.myVal) }
updateStateWithResult(result)
}
is SecondIntent -> IO { updateStateWithResult(intent.myVal) }
}
}
}
I do not know how I am supposed to make this IO stuff run in Dispatcher.IO like I've been doing with viewModelScope.launch. I can't find an example for how to do this with Arrow. The ones that make API calls all seem to be something other than Android apps, so there is no guidance about Android UI vs IO threads.
View model unit test
Now, because one benefit I'm seeing to this is that when I write my view model's unit tests, I can have a test. If I mock the repository in order to check whether suspendFunctionManipulatingDatabase is called with the expected parameter.
#Test
fun myTest() {
val result: IO<Unit> = viewModel.instruct(someIntent)
result.unsafeRunSync()
// verify suspendFunctionManipulatingDatabase argument was as expected
}
Activity
I do not know how to incorporate the above into my Activity.
class MyActivity: AppCompatActivity() {
private val viewModel = MyViewModel()
override fun onCreateView() {
viewModel.state.observe(this, Observer { render(it) })
myWidget.onClickObserver = {
viewModel.instruct(someIntent).unsafeRunSync() // Is this how I should do it?
}
}
// ...
}
My understanding is anything in an IO block does not run right away (i.e., it's lazy). You have to call attempt() or unsafeRunSync() to get the contents to be evaluated.
Calling viewModel.instruct from Activity means I need to create some scope and invoke in Dispatchers.IO right? Is this Bad(TM)? I was able to confine coroutines completely to the view model using the "traditional" method.
Where do I incorporate Dispatchers.IO to replicate what I did with viewModelScope.launch(Dispatchers.IO)?
Is this the way you're supposed to structure a unit test when using Arrow's IO?
That's a really good post to read indeed. I'd also recommend digging into this sample app I wrote that is using ArrowFx also.
https://github.com/JorgeCastilloPrz/ArrowAndroidSamples
Note how we build the complete program using fx and returning Kind at all levels in our architecture. That makes the code polymorphic to the type F, so you can run it using different runtime data types for F at will, depending on the environment. In this case we end up running it using IO at the edges. That's the activity in this case, but could also be the application class or a fragment. Think about this as what'd be the entry points to your apps. If we were talking about jvm programs the equivalent would be main(). This is just an example of how to write polymorphic programs, but you could use IO.fx instead and return IO everywhere, if you want to stay simpler.
Note how we use continueOn() in the data source inside the fx block to leave and come back to the main thread. Coroutine context changes are explicit in ArrowFx, so the computation jumps to the passed thread right after the continueOn until you deliberately switch again to a different one. That intentionally makes thread changes explicit.
You could inject those dispatchers to use different ones in tests. Hopefully I can provide examples of this soon in the repo, but you can probably imagine how this would look.
For the syntax on how to write tests note that your program will return Kind (if you go polymorphic) or IO, so you would unsafeRunSync it from tests (vs unsafeRunAsync or unsafeRunAsyncCancellable in production code since Android needs it to be asynchronous). That is because we want our test to be synchronous and also blocking (for the latter we need to inject the proper dispatchers).
Current caveats: The solution proposed in the repo still doesn't care of cancellation, lifecycle or surviving config changes. That's something I'd like to address soon. Using ViewModels with a hybrid style might have a chance. This is Android so I'd not fear hybrid styles if that brings better productivity. Another alternative I've got in mind would maybe be something a bit more functional. ViewModels end up retaining themselves using the retain config state existing APIs under the hood by using the ViewModelStore. That ultimately sounds like a simple cache that is definitely a side effect and could be implemented wrapped into IO. I want to give a thought to this.
I would definitely also recommend reading the complete ArrowFx docs for better understanding: https://arrow-kt.io/docs/fx/ I think it would be helpful.
For more thoughts on approaches using Functional Programming and Arrow to Android you can take a look to my blog https://jorgecastillo.dev/ my plan is to write deep content around this starting 2020, since there's a lot of people interested.
In the other hand, you can find me or any other Arrow team maintainers in the Kotlinlang JetBrains Slack, where we could have more detailed conversations or try to resolve any doubts you can have https://kotlinlang.slack.com/
As a final clarification: Functional Programming is just a paradigm that resolves generic concerns like asynchrony, threading, concurrency, dependency injection, error handling, etc. Those problems can be found on any program, regardless of the platform. Even within an Android app. That is why FP is an option as valid for mobile as any other one, but we are still into explorations to provide the best APIs to fulfill the usual Android needs in a more ergonomic way. We are in the process of exploration in this sense, and 2020 is going to be a very promising year.
Hopefully this helped! Your thoughts seem to be well aligned with how things should work in this approach overall.
I have a ViewModel in my android app, that has some logic, and the view needs to be adjusted/perform different things depending on the result of that logic. At first I tried to do it exclusively with observers and reacting to the state of the data in the viewmodel, but it was too complicated.
Then I found the concept of commands using the SingleLiveEvent class, and I found it good because it reminds me the same pattern when using Xamarin and the microsoft's mvvvm. One of the (few) good things that working with xamarin has ;)
Well, the problem in my case is that when I have more than one command that needs to be send to the view, the view is receiving only one command. Sometimes the last one, sometimes the first one. For example, a couple of commands that order the view to perform complicated things:
sealed class CustomCommands{
class CustomCommand1 : CustomCommands()
class CustomCommand2() : CustomCommands()
class CustomCommand3() : CustomCommands()
class CustomCommand4() : CustomCommands()
class CustomCommand5() : CustomCommands()
}
Then in my viewModel, I have the commands SingleLiveEvent object:
class CustomViewModel...{
val commands: SingleLiveEvent<CustomCommands> = SingleLiveEvent()
private fun doComplicatedThingsOnTheUI() {
GlobalScope.launch(Dispatchers.IO) {
if (someConditionsInvolvingRestRequestsAndDatabaseOperations()){
commands.postValue(CustomCommands.CustomCommand1())
commands.postValue(CustomCommands.CustomCommand2())
} else {
commands.postValue(CustomCommands.CustomCommand3())
commands.postValue(CustomCommands.CustomCommand4())
}
commands.postValue(CustomCommands.CustomCommand5())
}
}
}
And in the Activity/Fragment, I have the observer for the commands, that should react for each command and does the work:
class MainActivity...{
viewModel.commands.observe(this, Observer { command ->
Rlog.d("SingleLiveEvent", "Observer received event: " + command.javaClass.simpleName)
when (command) {
Command1->doSomething1()
Command2->doSomething2()
}
}
Well, the problem is that the view is normally receiving only the last command (Command5). But the behaviour depends on the api level of the Android SDK. By api 16, the view receives the last command. By Api 28, the view receives normally the first and the last command (for example, Command1 and Command5, but not Command2).
Maybe I'm understanding the capabilities of the SingleLiveEvent class wrong, or the whole Command thing wrong, but I need a way to allow the viewmodel to order the view to do somethings depending on the state of many objects and variables. The code above is only a sample, the reality es more complicated than that.
I don't want to use callbacks between the viewmodel and the view, because I read somewhere that that breaks the whole MVVM pattern.
Maybe someone has an advice for me. Any help would be welcome.
Thank you in advance.
I think I found a workaround, that seems to work (I have tested it only a couple of hours).
The thing is that I'm using "command.postValue(XXX)", because that piece of code is running inside a couroutine, that is, in other thread. Because of that I can not use command.value directly.
But the fact is that using command.value=Command1(), it works. I mean, the view receives all the commands sent, and very important too, with the same order as they were sent. Because of that I wrote a little funcion to send the commands to the UI switching the thread.
I'm not sure if this is correct, I'm a new to Kotlin coroutines and I have to admit that I don't understand them very well yet:
private suspend fun sendCommandToView(vararg icommands: CustomCommands) = withContext(Dispatchers.Main) {
icommands.forEach {
commands.value = it
}
}
And then I send the commands
sendCommandToView(CustomCommand1(),CustomCommand2(),CustomCommand5())
This seems to work. Thougt that the "post" method would work in a similar way, but it does not.
Regards.
I am trying to develop a nativescript plugin to perform some functionality with the Azure SDK. The docs for the SDK show below:
So I have added the following function to my plugin:
MobileServiceUser.newUser = function (userId, client) {
var userObject = com.microsoft.windowsazure.mobileservices.authentication.MobileServiceUser(userId); // causing the error
client.setCurrentUser(userObject);
};
UserId is a string.
However, the top line throws the error:
JS: Error: Trying to link invalid 'this' to a Java object
I have a full repo showing the minimal implimentation to create this issue on Github.
I would be really grateful of any suggestions how to fix this.
This answer is a little late but I recently ran into this issue myself. Hopefully this answer helps someone in the future!
The error is a bit plain but if you take a look at the code source, you'll see that it's actually telling you that you cannot link a variable to the Object/Class itself as a reference:
MobileServiceUser.newUser = function (userId, client) {
var userObject = com.microsoft.windowsazure.mobileservices.authentication.MobileServiceUser(userId);
};
When you want to instantiate a class, you need to use the keyword new to signify this action. Without new listed before the class constructor call, the program just sees that you're making a direct link between userObject and the class itself. This should fix your problem:
var userObject = new com.microsoft.windowsazure.mobileservices.authentication.MobileServiceUser(userId);
Cheers
~Px
I wrote a native module in Android that needs to send data to my React Native JS code.
However, the data I wish to send is a complex model and isn't one of basic types (int, double, array, etc.).
Here is method in the native module:
#ReactMethod
public void getDeviceInfo(final Callback successCallback, final Callback errorCallback) {
successCallback.invoke(new SomeComplexModel());
}
The application crashes (can't find any log) when trying to invoke the success method (same goes when trying to use Promises).
One way to tackle this problem is mapping the complex model into WriteableMap or something like that, but I'd prefer not to.
Do I have another choice?
I followed this tutorial: https://facebook.github.io/react-native/docs/native-modules-android.html