Hi) I'm a bit confused about coroutines on Android: Example 1:

launch(IO) {
            val result = repoRepository.getAllRepos()
            withContext(Main) {
                textField.text = result
            }
        }

Example 2:

launch(Main) {
            val result = repoRepository.getAllRepos()
            withContext(Main) {
                textField.text = result
            }
        }

Question is why i'm not getting android.os.NetworkOnMainThreadException in second example?

Does

getAllRepose()

do the actual fetching from the network, or does it just block and waits for an other thread, that does the networking, to return the result.

getAllRepose()

do the actual fetching from the network:

class RepoRepositoryImpl @Inject constructor(
        private val apiService: APIService
) : RepoRepository {

    override suspend fun getAllRepos(orgName: String) : List<RepoDto> {
        return apiService.getAllRepos(orgName).await()
    }

}

But

apiService.getAllRepos()

does all the work, maybe on a different thread.

APIService is just Retrofit Service:

interface APIService {

    @GET("/orgs/kotlin/repos")
    fun getAllReposRx(): Single<List<RepoDto>>

    @GET("/orgs/{org}/repos")
    fun getAllRepos(@Path("org") orgName: String): Deferred<List<RepoDto>>

}

Yep. And retrofit may use its own (IO) Dispatcher.

Under the hood OkHttpClient uses new Thread() for network request - that is for sure

There's no network on the main thread that would block it, there's just a coroutine suspending until some stuff done on another thread/dispatcher/executor completes and resumes it (and that stuff happens to do network I/O)

Parsing doesn’t necessarily involve network communication. It maybe just parsing a string that is in memory

Looks like CoroutineCallAdapterFactory did the trick here 🙂

Under the hood OkHttpClient uses new Thread() for network request - that is for sure

This is not exactly correct, OkHttp uses own dispatcher with thread pool

Yeap.