This compiler plugin enables you to enforce named arguments on on certain methods' invocations.

If you would like to enforce named arguments on all method invocations, then it is better to use scalastyle.

In your build.sbt, add:

resolvers += Resolver.bintrayRepo("givers", "maven")

scalacOptions ++= Seq(
  "-P:named-argument:annotation:framework.ForceNamedArgument"    // Enforce certain method invocations with named arguments
)

addCompilerPlugin("givers.scala.namedargument" %% "scala-named-argument-compiler-plugin" % "0.1.0")

Notice that -P:named-argument:annotation: (in scalacOptions) points the class framework.ForceNamedArgument (You can change this class to your liking).

With the scalacOptions above, please add the below class to your project:

package framework

import scala.annotation.StaticAnnotation

class ForceNamedArgument extends StaticAnnotation

Then, for any method that you would like to enforce named arguments, you can annotate the method with @ForceNamedArgument as shown below:

@framework.ForceNamedArgument
def toJson(showName: Boolean = true, showSecret: Boolean = false): JsValue = { ... }