nowarn plugin

This is a Scala 2 and 3 compiler plugin to configure custom annotations that expand into @annotation.nowarn annotations before the typer phase.

Install

Add the resolver and compiler plugin dependency to your build.sbt:

resolvers += "bondlink-maven-repo" at "https://raw.githubusercontent.com/mblink/maven-repo/main"
addCompilerPlugin("bondlink" %% "nowarn-plugin" % "1.1.1")

Configure

To configure a new annotation via the plugin, pass additional flags to scalac. The format of a flag is:

-P:nowarn:<annotation-name>:<nowarn-config>

Where nowarn-config is a string to be passed to @annotation.nowarn, e.g. cat=deprecation or msg=never used. You can find more info on configuring the nowarn annotation here.

For example, to create an @unused annotation that expands to @annotation.nowarn("msg=never used") add the following to your build.sbt:

scalacOptions += "-P:nowarn:unused:msg=never used"

You can also put periods in the annotation name to mirror your preferred package path, e.g.

scalacOptions += "-P:nowarn:my.pkg.unused:msg=never used"

Use

Once you've configured an annotation via a scalac option, you can use it in your code just like any other annotation:

def hasUnusedParam(@unused x: Int) = ...
def hasUnusedParam(@my.pkg.unused x: Int) = ...