Kotlin equivalent of Swift Expectations/Promises










1















I am trying to write some UnitTests for my native mobile applications, but have ran into a roadblock in my Android Tests. Specifically, I am struggling to find an example of Kotlin's version of Swift's Expectations/Promises..



I've found examples of Kotlin Promises, but they seem to be way more complicated than needed...



For example, here is a test for the login API function in my iOS project:



func testLogin() 

/// Prepare for login
if CURRENT_USER != nil
logout()


/// Login
let promise = expectation(description: "User is logged in.")

// 1. Given
var isSuccess: Bool = false

// 2. When
User.login(username: maleUsername, password: malePassword, success:
isSuccess = true
promise.fulfill()
) (_, agreeToTerms) in
XCTFail()

wait(for: [promise], timeout: maxTimeOut)

// 3. Then
XCTAssertNotNil(CURRENT_USER)
XCTAssertTrue(isSuccess)

/// Logout
logout()



This is pretty simple to me. I have an asynchronous method login that has two possible completion blocks: success and failure; and I need to wait for one of them to complete before evaluating. To do this, I create a promise before the call, then I fulfill the promise in the two completion blocks, and I wait for the promise to fulfill before running my assertions.



Now in Kotlin, I have a similar test:



private val loginFragment = LoginFragment()

@Test
fun loginTest()

val username = ""
val password = ""

// TODO: Create Promise

loginFragment.loginViewModel
.login(username, password)
.observe(loginFragment, Observer
loginFragment.activity?.onResult(it?.result,

onSuccess =
// TODO: Fill Promise
,
onValidationError =
// TODO: Fail Test
)
)

// TODO: Assertions




But I can't find an equivalent of swift's promises..



Does one exist in Kotlin? If not, how would I implement a version of my Swift's testLogin method in Kotlin?










share|improve this question






















  • This might help: medium.com/@tonyowen/…

    – Mike Taverne
    Nov 14 '18 at 1:48











  • The most straightforward analog of a promise on Kotlin-Android is the plain old CompletableFuture.

    – Marko Topolnik
    Nov 14 '18 at 9:03















1















I am trying to write some UnitTests for my native mobile applications, but have ran into a roadblock in my Android Tests. Specifically, I am struggling to find an example of Kotlin's version of Swift's Expectations/Promises..



I've found examples of Kotlin Promises, but they seem to be way more complicated than needed...



For example, here is a test for the login API function in my iOS project:



func testLogin() 

/// Prepare for login
if CURRENT_USER != nil
logout()


/// Login
let promise = expectation(description: "User is logged in.")

// 1. Given
var isSuccess: Bool = false

// 2. When
User.login(username: maleUsername, password: malePassword, success:
isSuccess = true
promise.fulfill()
) (_, agreeToTerms) in
XCTFail()

wait(for: [promise], timeout: maxTimeOut)

// 3. Then
XCTAssertNotNil(CURRENT_USER)
XCTAssertTrue(isSuccess)

/// Logout
logout()



This is pretty simple to me. I have an asynchronous method login that has two possible completion blocks: success and failure; and I need to wait for one of them to complete before evaluating. To do this, I create a promise before the call, then I fulfill the promise in the two completion blocks, and I wait for the promise to fulfill before running my assertions.



Now in Kotlin, I have a similar test:



private val loginFragment = LoginFragment()

@Test
fun loginTest()

val username = ""
val password = ""

// TODO: Create Promise

loginFragment.loginViewModel
.login(username, password)
.observe(loginFragment, Observer
loginFragment.activity?.onResult(it?.result,

onSuccess =
// TODO: Fill Promise
,
onValidationError =
// TODO: Fail Test
)
)

// TODO: Assertions




But I can't find an equivalent of swift's promises..



Does one exist in Kotlin? If not, how would I implement a version of my Swift's testLogin method in Kotlin?










share|improve this question






















  • This might help: medium.com/@tonyowen/…

    – Mike Taverne
    Nov 14 '18 at 1:48











  • The most straightforward analog of a promise on Kotlin-Android is the plain old CompletableFuture.

    – Marko Topolnik
    Nov 14 '18 at 9:03













1












1








1


1






I am trying to write some UnitTests for my native mobile applications, but have ran into a roadblock in my Android Tests. Specifically, I am struggling to find an example of Kotlin's version of Swift's Expectations/Promises..



I've found examples of Kotlin Promises, but they seem to be way more complicated than needed...



For example, here is a test for the login API function in my iOS project:



func testLogin() 

/// Prepare for login
if CURRENT_USER != nil
logout()


/// Login
let promise = expectation(description: "User is logged in.")

// 1. Given
var isSuccess: Bool = false

// 2. When
User.login(username: maleUsername, password: malePassword, success:
isSuccess = true
promise.fulfill()
) (_, agreeToTerms) in
XCTFail()

wait(for: [promise], timeout: maxTimeOut)

// 3. Then
XCTAssertNotNil(CURRENT_USER)
XCTAssertTrue(isSuccess)

/// Logout
logout()



This is pretty simple to me. I have an asynchronous method login that has two possible completion blocks: success and failure; and I need to wait for one of them to complete before evaluating. To do this, I create a promise before the call, then I fulfill the promise in the two completion blocks, and I wait for the promise to fulfill before running my assertions.



Now in Kotlin, I have a similar test:



private val loginFragment = LoginFragment()

@Test
fun loginTest()

val username = ""
val password = ""

// TODO: Create Promise

loginFragment.loginViewModel
.login(username, password)
.observe(loginFragment, Observer
loginFragment.activity?.onResult(it?.result,

onSuccess =
// TODO: Fill Promise
,
onValidationError =
// TODO: Fail Test
)
)

// TODO: Assertions




But I can't find an equivalent of swift's promises..



Does one exist in Kotlin? If not, how would I implement a version of my Swift's testLogin method in Kotlin?










share|improve this question














I am trying to write some UnitTests for my native mobile applications, but have ran into a roadblock in my Android Tests. Specifically, I am struggling to find an example of Kotlin's version of Swift's Expectations/Promises..



I've found examples of Kotlin Promises, but they seem to be way more complicated than needed...



For example, here is a test for the login API function in my iOS project:



func testLogin() 

/// Prepare for login
if CURRENT_USER != nil
logout()


/// Login
let promise = expectation(description: "User is logged in.")

// 1. Given
var isSuccess: Bool = false

// 2. When
User.login(username: maleUsername, password: malePassword, success:
isSuccess = true
promise.fulfill()
) (_, agreeToTerms) in
XCTFail()

wait(for: [promise], timeout: maxTimeOut)

// 3. Then
XCTAssertNotNil(CURRENT_USER)
XCTAssertTrue(isSuccess)

/// Logout
logout()



This is pretty simple to me. I have an asynchronous method login that has two possible completion blocks: success and failure; and I need to wait for one of them to complete before evaluating. To do this, I create a promise before the call, then I fulfill the promise in the two completion blocks, and I wait for the promise to fulfill before running my assertions.



Now in Kotlin, I have a similar test:



private val loginFragment = LoginFragment()

@Test
fun loginTest()

val username = ""
val password = ""

// TODO: Create Promise

loginFragment.loginViewModel
.login(username, password)
.observe(loginFragment, Observer
loginFragment.activity?.onResult(it?.result,

onSuccess =
// TODO: Fill Promise
,
onValidationError =
// TODO: Fail Test
)
)

// TODO: Assertions




But I can't find an equivalent of swift's promises..



Does one exist in Kotlin? If not, how would I implement a version of my Swift's testLogin method in Kotlin?







swift unit-testing kotlin promise






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Nov 13 '18 at 23:34









BlondeSwanBlondeSwan

1098




1098












  • This might help: medium.com/@tonyowen/…

    – Mike Taverne
    Nov 14 '18 at 1:48











  • The most straightforward analog of a promise on Kotlin-Android is the plain old CompletableFuture.

    – Marko Topolnik
    Nov 14 '18 at 9:03

















  • This might help: medium.com/@tonyowen/…

    – Mike Taverne
    Nov 14 '18 at 1:48











  • The most straightforward analog of a promise on Kotlin-Android is the plain old CompletableFuture.

    – Marko Topolnik
    Nov 14 '18 at 9:03
















This might help: medium.com/@tonyowen/…

– Mike Taverne
Nov 14 '18 at 1:48





This might help: medium.com/@tonyowen/…

– Mike Taverne
Nov 14 '18 at 1:48













The most straightforward analog of a promise on Kotlin-Android is the plain old CompletableFuture.

– Marko Topolnik
Nov 14 '18 at 9:03





The most straightforward analog of a promise on Kotlin-Android is the plain old CompletableFuture.

– Marko Topolnik
Nov 14 '18 at 9:03












1 Answer
1






active

oldest

votes


















0














You can use Kotlin coroutines, for example:



@Test
fun loginTest()
val result = runBlocking
val loginResult = login()
loginResult

if (result == "Success")
// do your work when Success
else
// do your work when Error


suspend fun login(): String = suspendCoroutine continuation ->
val username = ""
val password = ""
loginFragment.loginViewModel
.login(username, password)
.observe(loginFragment, Observer
loginFragment.activity?.onResult(it?.result,

onSuccess =
continuation.resume("Success")
,
onValidationError =
continuation.resume("Error") // take a look for other methods, e.g. resumeWithException(exception)

)
)



To use coroutines you need to add next lines to app's build.gradle file dependencies:




final KOTLIN_COROUTINES_VERSION = '1.0.1'
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$KOTLIN_COROUTINES_VERSION"



Hope it will help.






share|improve this answer

























  • Thanks for the information. So if I were to use this, I would essentially have to write a suspend function and a function that runs the suspend function for every test?

    – BlondeSwan
    Nov 14 '18 at 16:09











  • Yes, the code is more clear and readable that way. You can try avoid of creating of login() method by moving suspendCoroutine block inside runBlocking , but there will be some mess in the code.

    – Sergey
    Nov 14 '18 at 16:51











  • Talk about the lesser of two evils... haha.

    – BlondeSwan
    Nov 14 '18 at 16:53











  • I prefer to create a new method with suspendCoroutine block :)

    – Sergey
    Nov 14 '18 at 16:56











  • I'll be doing separate methods. Kotlin is kinda lame in the sense that you have to choose between (A) concise, but complicated, ultra-nested, messy code or (B) expansive, but simple, readable, clean code. Swift seems to be both clean and concise

    – BlondeSwan
    Nov 14 '18 at 17:04










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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









0














You can use Kotlin coroutines, for example:



@Test
fun loginTest()
val result = runBlocking
val loginResult = login()
loginResult

if (result == "Success")
// do your work when Success
else
// do your work when Error


suspend fun login(): String = suspendCoroutine continuation ->
val username = ""
val password = ""
loginFragment.loginViewModel
.login(username, password)
.observe(loginFragment, Observer
loginFragment.activity?.onResult(it?.result,

onSuccess =
continuation.resume("Success")
,
onValidationError =
continuation.resume("Error") // take a look for other methods, e.g. resumeWithException(exception)

)
)



To use coroutines you need to add next lines to app's build.gradle file dependencies:




final KOTLIN_COROUTINES_VERSION = '1.0.1'
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$KOTLIN_COROUTINES_VERSION"



Hope it will help.






share|improve this answer

























  • Thanks for the information. So if I were to use this, I would essentially have to write a suspend function and a function that runs the suspend function for every test?

    – BlondeSwan
    Nov 14 '18 at 16:09











  • Yes, the code is more clear and readable that way. You can try avoid of creating of login() method by moving suspendCoroutine block inside runBlocking , but there will be some mess in the code.

    – Sergey
    Nov 14 '18 at 16:51











  • Talk about the lesser of two evils... haha.

    – BlondeSwan
    Nov 14 '18 at 16:53











  • I prefer to create a new method with suspendCoroutine block :)

    – Sergey
    Nov 14 '18 at 16:56











  • I'll be doing separate methods. Kotlin is kinda lame in the sense that you have to choose between (A) concise, but complicated, ultra-nested, messy code or (B) expansive, but simple, readable, clean code. Swift seems to be both clean and concise

    – BlondeSwan
    Nov 14 '18 at 17:04















0














You can use Kotlin coroutines, for example:



@Test
fun loginTest()
val result = runBlocking
val loginResult = login()
loginResult

if (result == "Success")
// do your work when Success
else
// do your work when Error


suspend fun login(): String = suspendCoroutine continuation ->
val username = ""
val password = ""
loginFragment.loginViewModel
.login(username, password)
.observe(loginFragment, Observer
loginFragment.activity?.onResult(it?.result,

onSuccess =
continuation.resume("Success")
,
onValidationError =
continuation.resume("Error") // take a look for other methods, e.g. resumeWithException(exception)

)
)



To use coroutines you need to add next lines to app's build.gradle file dependencies:




final KOTLIN_COROUTINES_VERSION = '1.0.1'
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$KOTLIN_COROUTINES_VERSION"



Hope it will help.






share|improve this answer

























  • Thanks for the information. So if I were to use this, I would essentially have to write a suspend function and a function that runs the suspend function for every test?

    – BlondeSwan
    Nov 14 '18 at 16:09











  • Yes, the code is more clear and readable that way. You can try avoid of creating of login() method by moving suspendCoroutine block inside runBlocking , but there will be some mess in the code.

    – Sergey
    Nov 14 '18 at 16:51











  • Talk about the lesser of two evils... haha.

    – BlondeSwan
    Nov 14 '18 at 16:53











  • I prefer to create a new method with suspendCoroutine block :)

    – Sergey
    Nov 14 '18 at 16:56











  • I'll be doing separate methods. Kotlin is kinda lame in the sense that you have to choose between (A) concise, but complicated, ultra-nested, messy code or (B) expansive, but simple, readable, clean code. Swift seems to be both clean and concise

    – BlondeSwan
    Nov 14 '18 at 17:04













0












0








0







You can use Kotlin coroutines, for example:



@Test
fun loginTest()
val result = runBlocking
val loginResult = login()
loginResult

if (result == "Success")
// do your work when Success
else
// do your work when Error


suspend fun login(): String = suspendCoroutine continuation ->
val username = ""
val password = ""
loginFragment.loginViewModel
.login(username, password)
.observe(loginFragment, Observer
loginFragment.activity?.onResult(it?.result,

onSuccess =
continuation.resume("Success")
,
onValidationError =
continuation.resume("Error") // take a look for other methods, e.g. resumeWithException(exception)

)
)



To use coroutines you need to add next lines to app's build.gradle file dependencies:




final KOTLIN_COROUTINES_VERSION = '1.0.1'
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$KOTLIN_COROUTINES_VERSION"



Hope it will help.






share|improve this answer















You can use Kotlin coroutines, for example:



@Test
fun loginTest()
val result = runBlocking
val loginResult = login()
loginResult

if (result == "Success")
// do your work when Success
else
// do your work when Error


suspend fun login(): String = suspendCoroutine continuation ->
val username = ""
val password = ""
loginFragment.loginViewModel
.login(username, password)
.observe(loginFragment, Observer
loginFragment.activity?.onResult(it?.result,

onSuccess =
continuation.resume("Success")
,
onValidationError =
continuation.resume("Error") // take a look for other methods, e.g. resumeWithException(exception)

)
)



To use coroutines you need to add next lines to app's build.gradle file dependencies:




final KOTLIN_COROUTINES_VERSION = '1.0.1'
implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$KOTLIN_COROUTINES_VERSION"



Hope it will help.







share|improve this answer














share|improve this answer



share|improve this answer








edited Nov 15 '18 at 20:33

























answered Nov 14 '18 at 4:46









SergeySergey

2,84821631




2,84821631












  • Thanks for the information. So if I were to use this, I would essentially have to write a suspend function and a function that runs the suspend function for every test?

    – BlondeSwan
    Nov 14 '18 at 16:09











  • Yes, the code is more clear and readable that way. You can try avoid of creating of login() method by moving suspendCoroutine block inside runBlocking , but there will be some mess in the code.

    – Sergey
    Nov 14 '18 at 16:51











  • Talk about the lesser of two evils... haha.

    – BlondeSwan
    Nov 14 '18 at 16:53











  • I prefer to create a new method with suspendCoroutine block :)

    – Sergey
    Nov 14 '18 at 16:56











  • I'll be doing separate methods. Kotlin is kinda lame in the sense that you have to choose between (A) concise, but complicated, ultra-nested, messy code or (B) expansive, but simple, readable, clean code. Swift seems to be both clean and concise

    – BlondeSwan
    Nov 14 '18 at 17:04

















  • Thanks for the information. So if I were to use this, I would essentially have to write a suspend function and a function that runs the suspend function for every test?

    – BlondeSwan
    Nov 14 '18 at 16:09











  • Yes, the code is more clear and readable that way. You can try avoid of creating of login() method by moving suspendCoroutine block inside runBlocking , but there will be some mess in the code.

    – Sergey
    Nov 14 '18 at 16:51











  • Talk about the lesser of two evils... haha.

    – BlondeSwan
    Nov 14 '18 at 16:53











  • I prefer to create a new method with suspendCoroutine block :)

    – Sergey
    Nov 14 '18 at 16:56











  • I'll be doing separate methods. Kotlin is kinda lame in the sense that you have to choose between (A) concise, but complicated, ultra-nested, messy code or (B) expansive, but simple, readable, clean code. Swift seems to be both clean and concise

    – BlondeSwan
    Nov 14 '18 at 17:04
















Thanks for the information. So if I were to use this, I would essentially have to write a suspend function and a function that runs the suspend function for every test?

– BlondeSwan
Nov 14 '18 at 16:09





Thanks for the information. So if I were to use this, I would essentially have to write a suspend function and a function that runs the suspend function for every test?

– BlondeSwan
Nov 14 '18 at 16:09













Yes, the code is more clear and readable that way. You can try avoid of creating of login() method by moving suspendCoroutine block inside runBlocking , but there will be some mess in the code.

– Sergey
Nov 14 '18 at 16:51





Yes, the code is more clear and readable that way. You can try avoid of creating of login() method by moving suspendCoroutine block inside runBlocking , but there will be some mess in the code.

– Sergey
Nov 14 '18 at 16:51













Talk about the lesser of two evils... haha.

– BlondeSwan
Nov 14 '18 at 16:53





Talk about the lesser of two evils... haha.

– BlondeSwan
Nov 14 '18 at 16:53













I prefer to create a new method with suspendCoroutine block :)

– Sergey
Nov 14 '18 at 16:56





I prefer to create a new method with suspendCoroutine block :)

– Sergey
Nov 14 '18 at 16:56













I'll be doing separate methods. Kotlin is kinda lame in the sense that you have to choose between (A) concise, but complicated, ultra-nested, messy code or (B) expansive, but simple, readable, clean code. Swift seems to be both clean and concise

– BlondeSwan
Nov 14 '18 at 17:04





I'll be doing separate methods. Kotlin is kinda lame in the sense that you have to choose between (A) concise, but complicated, ultra-nested, messy code or (B) expansive, but simple, readable, clean code. Swift seems to be both clean and concise

– BlondeSwan
Nov 14 '18 at 17:04

















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