Purr is an sbt-plugin that helps me add a few libraries to a project I often use, namely:
By adding this plugin, you automatically pull in those libraries with compatible versions.
Add the purr plugin to plugins.sbt:
addSbtPlugin("ch.timo-schmid" % "sbt-purr" % "{ latest version }")In your build.sbt, enable the purr plugin for your webserver project:
lazy val server = (project in file("server")).enablePlugins(PurrPlugin)That's it! Purr will automatically add those libraries in recent versions:
Seq(
"org.typelevel" %% "cats-core" % catsVersion.value,
"org.typelevel" %% "cats-effect" % catsEffectVersion.value,
"org.http4s" %% "http4s-blaze-server" % http4sVersion.value,
"org.http4s" %% "http4s-blaze-client" % http4sVersion.value,
"org.http4s" %% "http4s-circe" % http4sVersion.value,
"org.http4s" %% "http4s-dsl" % http4sVersion.value,
"io.circe" %% "circe-core" % circeVersion.value,
"io.circe" %% "circe-parser" % circeVersion.value,
"io.circe" %% "circe-generic" % circeVersion.value,
"ch.qos.logback" % "logback-classic" % logbackVersion.value,
"io.chrisdavenport" %% "log4cats-core" % log4catsVersion.value,
"io.chrisdavenport" %% "log4cats-log4s" % log4catsVersion.value,
"co.fs2" %% "fs2-core" % fs2Version.value,
"co.fs2" %% "fs2-cats" % fs2CatsVersion.value
)Also, purr will add two plugins:
Seq(
"org.spire-math" %% "kind-projector" % kindProjectorVersion.value asCompilerPlugin,
"com.olegpy" %% "better-monadic-for" % betterMonadicForVersion.value asCompilerPlugin
)You can customize each of the versions by setting the keys in Keys.scala. An example: At the time of writing this, the latest version of http4s used by purr is "0.19.0-M4", but now lets say "0.19.0" is released, and you want to update. You don't have to wait for it to change - just set the http4sVersion setting to "0.19.0" (or whatever version you want).
lazy val server = (project in file("server")).settings(
http4sVersion := "0.19.0"
).enablePlugins(PurrPlugin)Notice there are no compatibility checks in place. If - for example - your version of http4s depends on a newer version of cats than circe, they might not be binary compatible.