Upgrading from 0.18
Automated upgrading with scalafix
Http4s 0.20 comes with a scalafix that does some of the migration automatically.
Before you upgrade manually, we recommend you run this scalafix.
Make sure your scala version is >=
Add the scalafix plugin to your
project/plugins.sbt or to your global plugins.
addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.9.1")
$ sbt ";scalafixEnable; scalafix github:http4s/http4s/v0_20"
The compiler errors should help you in showing what’s left to upgrade.
For further information about the changes from 0.18, check the changelog