coroutines - Dan Lew Codes

coroutines

A collection of 4 posts

Do or do not; there is no tryEmit()

In RxJava, PublishSubject [http://reactivex.io/RxJava/3.x/javadoc/io/reactivex/rxjava3/subjects/PublishSubject.html] (or PublishRelay [https://github.com/JakeWharton/RxRelay] if you’re a cool kid) is a gizmo for manually pumping data into streams like in this contrived example: private val socketSubject = PublishSubject.create<String&

RxJava vs. Coroutines

At Trello Android, we’ve been considering switching from RxJava to coroutines. We’ve already been using coroutines here and there, but it wasn’t something that we could consider replacing RxJava with until recently because of missing functionality. Now, with the addition of StateFlow and SharedFlow [https://blog.jetbrains.

Testing Never-Ending Flows

Suppose we’ve got an RxJava test to verify that a stream never emits anything*: @Test fun verifyNeverEmits() { Observable.never<String>().subscribe { fail() } } How would the equivalent one look like for Flow? Suppose I’m testing a theoretical neverFlow(): @Test fun verifyNeverCollects() = runBlocking { neverFlow().collect { fail() } } There’s

Coroutines and Java Synchronization Don't Mix

Suppose you've got a critical section [https://en.wikipedia.org/wiki/Critical_section] of code, meaning only one process should execute it at a time. In the Java world, one solution is to slap synchronized on the method and call it a day. In Kotlin, we use @Synchronized