bartholomews / fsclient

Http wrapper on top of http4s


CircleCI codecov Maven Central License: Unlicense Cats friendly


🔧 This project is still early stage and very much WIP / experimental 🔧

libraryDependencies += "io.bartholomews" %% "fsclient" % "<VERSION>"

Opinionated http client on top of http4s/fs2

Motivation for this project is to

  • play around with the Typelevel stack
  • set up oAuth handling, logging, codecs patterns for api clients
import cats.effect.{ContextShift, IO}
import io.bartholomews.fsclient.client.FsClientV1
import io.bartholomews.fsclient.codecs.FsJsonResponsePipe
import io.bartholomews.fsclient.config.UserAgent
import io.bartholomews.fsclient.entities._
import io.bartholomews.fsclient.entities.oauth.OAuthVersion.OAuthV1
import io.bartholomews.fsclient.entities.oauth.{ClientCredentials, Signer}
import io.bartholomews.fsclient.requests.{FsSimpleRequest, JsonRequest}
import io.bartholomews.fsclient.utils.HttpTypes.HttpResponse
import io.circe.{Decoder, Json}
import org.http4s.Uri

import scala.concurrent.ExecutionContext

object Example extends App {

  implicit val ec: ExecutionContext =
  implicit val cs: ContextShift[IO] = IO.contextShift(ec)

  // will add header `User-Agent: myapp/0.0.1-SNAPSHOT (+com.github.bartholomews)` to all requests
  val userAgent = UserAgent(
    appName = "myapp",
    appVersion = Some("0.0.1-SNAPSHOT"),
    appUrl = Some("com.github.bartholomews")

  val consumer = org.http4s.client.oauth1.Consumer(
    key = "kasldklSAJSALKDKAsd",
    secret = "asjdoASIDJASOdjasojdoasijd"

  // Sign with consumer key/secret, but without token
  // Otherwise you can use `AuthVersion.V1.OAuthToken`
  val signer: Signer = ClientCredentials(consumer)

  // Define your expected response entity
  case class Todo(userId: Long, id: Long, title: String, completed: Boolean)
  // `FsJsonResponsePipe` is necessary to derive the fs2 Pipe decoder
  object Todo extends FsJsonResponsePipe[Todo] {
    implicit val decoder: Decoder[Todo] = io.circe.generic.semiauto.deriveDecoder

  // You also need this for common codecs like empty body encoder and raw json decoder
  import io.bartholomews.fsclient.implicits._

    `FsSimpleRequest` has three type parameters:
      Body: the request body
      Raw: the raw response content-type
      Res: the decoded response into your own type
    Depending on the types you will be forced to add the request body
    and have the right implicits in scope for the codecs
  val req: FsSimpleRequest[Nothing, Json, Todo] = new JsonRequest.Get[Todo] {
    override val uri: Uri = org.http4s.Uri.unsafeFromString("")

  // Run your `FsSimpleRequest` with the client for your effect
  val res: IO[HttpResponse[Todo]] = req.runWith(FsClientV1[IO, OAuthV1](userAgent, signer))

  val response = res.unsafeRunSync()

    case ErrorBodyString(error) => println(error)
    case ErrorBodyJson(error)   => println(error.spaces2)
  }, todo => println(todo.title))

CircleCI deployment

Verify local configuration

circleci local execute

CI/CD Pipeline

This project is using sbt-ci-release plugin:

  • Every push to master will trigger a snapshot release.

  • In order to trigger a regular release you need to push a tag:

    ./scripts/ v1.0.0
  • If for some reason you need to replace an older version (e.g. the release stage failed):

    git push --delete origin ${TAG} && git tag --delete ${TAG} \
    && ./scripts/ ${TAG}