👀 Views: 0 💬 Answers: 1 📅 Created: 2025-09-20

scala zio http4s

Currently developing a research application that leverages ZIO for handling asynchronous operations while using Http4s for API interactions. I've set up my project with the following dependencies: ```scala libraryDependencies ++= Seq( "org.http4s" %% "http4s-blaze-server" % "0.21.22", "org.http4s" %% "http4s-blaze-client" % "0.21.22", "dev.zio" %% "zio" % "1.0.9", "dev.zio" %% "zio-http4s" % "0.1.4" ) ``` The application needs to communicate with an external REST API to fetch some data, but I've noticed inconsistencies during testing. More specifically, the timeouts seem to vary greatly, and occasionally the calls fail due to `java.util.concurrent.TimeoutException`. I suspect it has something to do with the way I'm setting up my environment or handling the ZIO effects. In an attempt to isolate the problem, I've created a simple test case using `ZIO.test` along with `Http4s` client setup like this: ```scala val program: ZIO[Client, Throwable, Response[IO]] = for { client <- ZIO.service[Client] request = Request[IO](Method.GET, uri"http://example.com/api/data") response <- client.fetch(request) { response => ZIO.succeed(response) } } yield response ``` Running this in isolation sometimes succeeds, but other times it throws an error. I've tried adjusting the client timeout settings by specifying a custom configuration: ```scala val config: BlazeClientConfig = BlazeClientConfig.defaultConfig.copy(requestTimeout = 5.seconds) val clientResource: Resource[IO, Client] = BlazeClientBuilder[IO](ExecutionContext.global) .withConfig(config) .resource ``` Despite these configurations, the timeouts still occur in the tests. Could it be a problem with the ZIO effect not properly managing the resources, or are there specific practices I should consider while combining these two libraries? Any insights or best practices for robust asynchronous testing with ZIO and Http4s would be greatly appreciated.