I have a requirement to get responses from multiple requests with different models in RxSwift. I want to do this without GCD or Semaphore and only with RxSwift.
I try this code but have some problems with in different responses with different models and counts of results objects.
Observable.zip(service.fetchAlbums(), service.fetchUsers())
.subscribe(onNext: { (albums, users) in
print(albums)
print(users)
})
.disposed(by: self.disposeBag)
The following works fine.
import RxSwift
func example(service: Service, disposeBag: DisposeBag) {
Observable.zip(service.fetchAlbums(), service.fetchUsers())
.subscribe(onNext: { (albums, users) in
print(albums)
print(users)
})
.disposed(by: disposeBag)
}
protocol Service {
func fetchAlbums() -> Observable<[Album]>
func fetchUsers() -> Observable<[User]>
}
struct Album { }
struct User { }
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")
}
Now I'm developing server application with ktor 2(2.0.0-eap-256).
What I want to do is, according to header or other information, Reject or set adequate http status to response and do not let request go into service logic.
Below is What I tried.
val testPlugin = createApplication("testPlugin") {
onCall {
if (call.request.headers["auth"] == null) {
call.respond(HttpStatusCode.BadRequest)
return#onCall
}
}
}
fun Application.testRouting() {
routing {
get("/") { call.respond("hello") }
}
}
fun Application.applyPlugin() {
install(testPlugin)
}
But request goes into service logic defined by routing(with response which has HttpStatusCode.BadRequest). Is there any idea?
And also, I want to ask my understand about onCall/onCallReceive/onCallRespond is right
onCall is invoked first, when request come.
then, onCallReceive is invoked to handle request data such as file, body, etc
after all service logic, onCallRespond is invoked.
Edit
About the last question, it is solved. onCallReceive is called when I invoke call.receive() to get request content
Edit
Add routing code
Edit
So, I edit plugin like this.
val testPlugin = createApplication(
name = "testPlugin",
createConfiguration = { TestPluginConfig() }
) {
pluginConfig.apply {
pipeline!!.intercept(ApplicationCallPipeline.Plugins){
if (call.request.headers["auth"] == null) {
call.respond(HttpStatusCode.BadRequest)
finish()
}
}
}
}
data class TestPluginConfig(
var pipeline: Application? = null // io.ktor.sever.Application
)
fun Application.testRouting() {
routing {
get("/") { call.respond("hello") }
}
}
fun Application.applyPlugin() {
val pipeline = this // io.ktor.sever.Application
install(testPlugin) { pipeline = pipeline }
}
It works just as I wanted
very thanks to Aleksei Tirman
According to Rustam Siniukov on the kotlin slack here it's enough to use call.respond in the plugin.
My tests confirmed this.
I was using restTemplate and this was my method:
fun fetchAvailableCars(): Aggregations? {
val availableCarsUrl = UriComponentsBuilder
.fromHttpUrl(getCatalogUrl())
.query("aggsBy={aggregators}")
.buildAndExpand("brand,model")
.toString()
return restTemplate.getForEntity(availableCarsUrl, Aggregations::class.java).body
}
I'm trying to use Fuel to do basically the same thing (but handling errors), but I couldn't find a simple way to do that.
This is what I have so far:
fun fetchAvailableCarsWithFuel() {
val availableCarsUrl = UriComponentsBuilder
.fromHttpUrl(getCatalogUrl())
.query("aggsBy={aggregators}")
.buildAndExpand("brand,model")
.toString()
Fuel.get(availableCarsUrl)
.responseObject<Aggregations> { _, _, result ->
when (result) {
is Success -> {
result.get()
}
is Failure -> {
// log.error
}
}
}
}
but there's no easy way to return the body from inside the lambda. What are the common ways to do that?
P.S.: I'm using fuel-jackson to deserialize the response
I've wanted to try RxJava with kotlin to make coding easier, so I've produced this:
fun postAnswers() {
disposable = getToken.execute().subscribe({ token ->
questions.forEach { form ->
val answers = form.answers?.filter { it.isChecked }?.map { it.answer_id }
disposable = postAnswer.execute(token?.token!!, SavedAnswer(form.form_id, answers)).subscribe({
//Post live data about success
}, {
//Post live data failure
})
}
}, {
//Post live data failure
})
}
But I have an impression it can be done better, but I do not know how. Basically what I am trying to achieve is getting a Token object from database, that returns Flowable Token? and then use it to call postAnswer in a for cycle, because I need to post each answer separately (That's how the API is designed). After that, postAnswer only returns Completable, but I need to let the Activity know (this is from ViewModel code) how many answers were posted
I've thought about using .flatMap or .concat functions, but I am not sure if it will be helpful in this case. Also, do I need to assign getToken.execute() to disposable?
Thank you for your answers
EDIT:
Here is my questions list:
private var questions: List<Form> = emptyList()
It gets filled by viewModel functions
Try to think with nesting :) This here will probably do: for each saved answer, post a request.
disposable = getToken.execute()
.switchMap { token -> // switchMap because your old token is probably invalidated
val savedAnswers = questions
.map { form->
val formId = form.form_id
form.answers
?.filter { it.isChecked }
?.map { it.answer_id }
?.let { SavedAnswer(formId, answersIds) }
?: SavedAnswer(formId, emptyList() ) // if no checked answer, then return empty list of ids
}
Observable.list(savedAnswers)
.concatMap { savedAnswer -> // concatMap because you want the whole list to be executed once per time, use flatMap if you want it to be in parallel.
postAnswer.execute(token?.token!!, savedAnswer) // FYI: !! is bad practice in Kotlin, try make it less anbiguous
}
.toList()
}
.subscribe({ listOfResultsFromPostings : List<SomeResultHere> ->
//Post live data about success
}, {
//Post live data failure
})
So I wanted to isolate controllers from models in testing so that I could easily figure out stuff if troubles arise. Before, I just hit the endpoints with mock data but it was difficult to troubleshoot because the test runs from the router all the way to the datastore. So I'm thinking maybe I'll just create two versions(MockController vs Controller) for each controller(and model) and use one depending on the value of the mode variable. In a nutshell, this is how I plan to implement it.
const mode string = "test"
// UserModelInterface is the Interface for UserModel
type UserModelInterface interface {
Get()
}
// UserControllerInterface is the Interface for UserController
type UserControllerInterface interface {
Login()
}
// NewUserModel returns a new instance of user model
func NewUserModel() UserModelInterface {
if mode == "test" {
return &MockUserModel{}
} else {
return &UserModel{}
}
}
// NewUserController returns a new instance of user controller
func NewUserController(um UserModelInterface) UserControllerInterface {
if mode == "test" {
return &MockUserController{}
} else {
return &UserController{}
}
}
type (
UserController struct {um UserModelInterface}
UserModel struct {}
// Mocks
MockUserController struct {um UserModelInterface}
MockUserModel struct {}
)
func (uc *UserController) Login() {}
func (um *UserModel) Get() {}
func (uc *MockUserController) Login() {}
func (um *MockUserModel) Get() {}
func main() {
um := NewUserModel()
uc := NewUserController(um)
}
This way I could just skip sql query in the MockUserController.Login() and only validate the payload and return a valid response.
What do you think of this design? Do you have a better implementation in mind?
I would let the code that calls NewUserController() and NewUserModel() decide whether to create a mock or real implementation. If you use that pattern of dependency injection all the way up to the top your code will become clearer and less tightly coupled. E.g. if the user controller is used by a server, it would look something like along the lines of:
Real:
u := NewUserController()
s := NewServer(u)
In tests:
u := NewMockUserController()
s := NewServer(u)
I would try a more slim variant spread over a models and a controllers package, like this:
// inside package controllers
type UserModel interface {
Get() // the methods you need from the user model
}
type User struct {
UserModel
}
// inside package models
type User struct {
// here the User Model
}
// inside package main
import ".....controllers"
import ".....models"
func main() {
c := &controllers.User{&models.User{}}
}
// inside main_test.go
import ".....controllers"
type MockUser struct {
}
func TestX(t *testing.T) {
c := &controllers.User{&MockUser{}}
}
For controller testing consider the ResponseRecorder of httptest package