Am building an API and using intercept(ApplicationCallPipeline.Call){} to run some logic before each route execution. I need to pass data from the intercept() method to the called route and
am setting data by using call.attributes.put() in the intercept() like this:
val userKey= AttributeKey<User>("userK")
call.attributes.put(userKey, userData)
And retrieve userData with call.attributes[userKey] .
What happens is that call.attributes[userKey] only works in the intercept() method where I have set the attribute. It doesn't work in the route where I need it.
It throws me
java.lang.IllegalStateException: No instance for key AttributeKey: userK
I wonder if am doing things in the right way
Here is the simplest code reproducing what you describe:
class KtorTest {
data class User(val name: String)
private val userKey = AttributeKey<User>("userK")
private val expected = "expected name"
private val module = fun Application.() {
install(Routing) {
intercept(ApplicationCallPipeline.Call) {
println("intercept")
call.attributes.put(userKey, User(expected))
}
get {
println("call")
val user = call.attributes[userKey]
call.respond(user.name)
}
}
}
#Test fun `pass data`() {
withTestApplication(module) {
handleRequest {}.response.content.shouldNotBeNull() shouldBeEqualTo expected
}
}
}
I intercept the call, put the user in the attributes, and finally respond with the user in the get request.
The test passes.
What ktor version are you using and which engine?
Related
I am a complete beginner in terms of Kotlin and I am finding some issues while trying to test out a Ktor based application.
I have a file in my endpoints package localized at org.example.endpoints.hello
this file contains a fun Application.hello that implements an endpoint for my application.
This endpoint acts as a wrapper for another API, so inside that same file I have a
fun callOtherAPI(): ResponseContainer {
// networking stuff
return ResponseContainer(message: "some stuff")
}
This function gets called inside the Application's function routing implementation as such:
routing {
get("/hello") {
call.respond(callOtherAPI())
}
}
Now to the issue:
My test currently looks like this:
#Test
fun testHello() = testApplication {
application {
hello()
}
mockkStatic(::callOtherAPI)
every { callOtherAPI() } returns ResponseContainer("hello")
print(callOtherAPI()) // This actually returns the mocked response, which is what I want
client.get("/hello").apply {
val expected = ResponseContainer("hello")
val response = jacksonObjectMapper().readValue<ResponseContainer>(bodyAsText())
assertEquals(HttpStatusCode.OK, status)
assertEquals(expected.message, response.message) // This assert fails because the internal call to callOtherAPI() is not being mocked.
}
}
So the problem that I am facing is that while the mocked function is being mocked within the context of the test, it is not being mocked when called internally by the routing implementation.
Can someone point me to good documentation to figure this out, I've been at it for the past two hours to no avail :/
Thanks!
You can declare a parameter for the callOtherAPI function in the hello method. For the production and testing environment you will pass different functions in this case. Here is your code rewritten:
#Test
fun testHello() = testApplication {
application {
// hello(::callOtherAPI) this call will be for the production environment
hello { ResponseContainer("hello") }
}
client.get("/hello").apply {
assertEquals(HttpStatusCode.OK, status)
assertEquals("{\"message\":\"hello\"}", bodyAsText())
}
}
data class ResponseContainer(val message: String)
fun Application.hello(callOtherAPI: () -> ResponseContainer) {
install(ContentNegotiation) {
jackson()
}
routing {
get("/hello") {
call.respond(callOtherAPI())
}
}
}
fun callOtherAPI(): ResponseContainer {
// networking stuff
return ResponseContainer("some stuff")
}
just started learning Kotlin. I'm trying to use okhttp to send a simple get request to a URL that contains only text.
I want the output of the request stored in a liveData variable, but when I run it, it crashes. Here's the class:
// gradle dependency added to build.gradle:
// implementation("com.squareup.okhttp3:okhttp:4.5.0")
//
// added this permission to AndroidManifest.xml just above the "application" section
// <uses-permission android:name="android.permission.INTERNET" />
//
import androidx.lifecycle.LiveData
import androidx.lifecycle.MutableLiveData
import okhttp3.OkHttpClient
import okhttp3.Request
import java.io.IOException
class GetExample {
private val client = OkHttpClient()
private val _theResult = MutableLiveData<String?>()
val theResult: LiveData<String?> = _theResult
#Throws(IOException::class)
fun getText(url: String) {
val request = Request.Builder().url(url).build()
try {
client.newCall(request).execute()
.use { response -> _theResult.value = response.body?.string() }
} catch (e: IOException) {
_theResult.value = e.message
}
}
}
And to call this I'm using
val url = "https://raw.github.com/square/okhttp/master/README.md"
GetExample().getText(url)
and accessing the result with
var thisString: String? = GetExample().theResult.value
Help greatly appreciated
Lets break down a little what your code does, shall we?
val url = "https://raw.github.com/square/okhttp/master/README.md"
GetExample().getText(url)
var thisString: String? = GetExample().theResult.value
You first assign the url variable to be a github link. Then, you construct a new GetExample object and call getText on it, with the url parameter.
But now, you are assigning thisString to a new instance of GetExample, which means it doesn't contain the data from the object you called getText on.
To fix this problem, one might write something like this:
val url = "https://raw.github.com/square/okhttp/master/README.md"
val getter = GetExample()
getter.getText(url)
var thisString: String? = getter.theResult.value
What george said is true as well, but I haven't tested that so you need to take a look if that is a problem as well.
You are trying to execute this on the UI thread. That will not work.
Just try to run it on another thread, like the IO Thread,
and use postValue in liveData. Otherwise, you need to set the value on the UI thread.
E.g.,
try {
runBlocking(IO) {
client.newCall(request).execute()
.use { response -> _theResult.postValue(response.body?.string()) }
}
} catch (e: IOException) {
_theResult.value = e.message
}
I try to achieve something similar to this: How to call a lambda callback with mockk
I pass a mocked service to my real object. How can I get the myService.get callback called? This code gets never called and my test stops at this request.
Here is some sample code:
class MyObject(private val myService: MyService){
fun getSomeStuff() {
myService.get(object: MyService.Callback<MyServiceResponse>{
override fun onResponse(response: MyServiceResponse?) {
// check response and do some stuff
// I want to continue my tests here, but this gets never called
}
})
}
How can I create a test that continues inside the callback?
Here is what I trie in my test:
#Test
fun `get some stuff - success`() {
val myService = mockk<MyService>() {
every { get(any()) } answers {
firstArg<() -> MyService.Callback<MyServiceResponse>>().invoke()
}
}
val myObject = MyObject(myService)
myObject.getSomeStuff()
}
You should be able to call onResponse() by using:
every { get(any()) }
answers {
firstArg<MyService.Callback<MyServiceResponse>>().onResponse(aMyServiceResponse)
}
By the way, as you are using a callback, I guess that the implementation is asynchronous, so you'll probably need to use the coEvery / coAnswer variant.
HTH
I create a mock of a class with mockk.
On this mock I now call a method that gets a lambda as a parameter.
This lambda serves as a callback to deliver state changes of the callback to the caller of the method.
class ObjectToMock() {
fun methodToCall(someValue: String?, observer: (State) -> Unit) {
...
}
}
How do I configure the mock to call the passed lambda?
You can use answers:
val otm: ObjectToMock = mockk()
every { otm.methodToCall(any(), any())} answers {
secondArg<(String) -> Unit>().invoke("anything")
}
otm.methodToCall("bla"){
println("invoked with $it") //invoked with anything
}
Within the answers scope you can access firstArg, secondArg etc and get it in the expected type by providing it as a generic argument. Note that I explicitly used invoke here to make it more readable, it may also be omitted.
I had to look for a bit more example for the callback and found some example in Kotlin Test with Mockk. In my case, it's a bit more specific.
I wanted to check and mock the onFailure and onSuccess case of a a custom callback implementation MyCustomCallback implementing the ListenableFutureCallback.
The code would look like that for my ExampleProducer class that would have a send function:
fun send(data: String) {
val responseFuture = kafkaTemplate.send(topic, data)
responseFuture.addCallback(MyCustomCallback())
}
So here who would the test go:
#Test
fun onFailureTest() {
kafkaTemplate: KafkaTemplate<String, String> = mockk()
val captureCallback = slot<ListenableFutureCallback<SendResult<String, String>>>()
every { callback.addCallback(capture(captureCallback)) } answers {
captureCallback.captured.onFailure(Throwable())
}
every { kafkaTemplate.send(any()) } returns callback
val prod: ExampleProducer = ExampleProducer()
prod.send("test")
// Then you can verify behaviour or check your captureCallback.captured
verify { kafkaTemplate.send(any()) }
assertNotNull(captureCallback.captured)
}
Maybe not exactly what you ask about, but you can use the funciton type for the mock:
val observerMock = mockk<(State) -> Unit>()
I come from Java and I'm following a tutorial online regarding using the Volley library to make web requests in Android.
The instructor created the request variable like this:
val registerRequest = object : StringRequest(Method.POST, URL_REGISTER, Response.Listener {
println(it) // will print the response
complete(true)
}, Response.ErrorListener {
Log.d("ERROR", "Could not register user: $it")
complete(false)
}) {
override fun getBodyContentType(): String {
return "application/json; charset=utf-8"
}
override fun getBody(): ByteArray {
return requestBody.toByteArray()
}
}
I understand that he's creating a registerRequest variable of type StringRequest. But what I don't understand is why he prefixed StringRequest with object : here.
Also I understand that StringRequest constructor takes in an Int, String, Lambda, Lambda. After that it becomes confusing to me because the developer was able to declare some override methods after the constructor closes. Why did they do this? From what I can tell, this is similar to subclassing StringRequest, then writing the override methods there? Am I right?
Coming from Java, this way of writing code is quite unusual to me.