Scala Warnings

Currently Scala 2.x is supported. Scala 3.x isn’t yet supported.

Tell us if you are using Scala 3, so we can prioritize supporting it.

Enable Scala compiler warnings in your build to see them in the pull requests.

In SBT

Enable the compiler flags for which you want to get warnings in the SBT build:

CODE

lazy val scalaExample = (project in file("."))
  .settings(
    name := "scala-sbt-example",
    scalacOptions += "-unchecked",
    scalacOptions += "-feature",
    scalacOptions += "-deprecation",
    scalacOptions += "-Ywarn-numeric-widen",
    scalacOptions += "-Ywarn-value-discard",
    scalacOptions += "-Ywarn-unused",
  )

In Maven

Enable the compiler flags for which you want to get warnings in the Maven build:

CODE

<plugin>
    <groupId>net.alchim31.maven</groupId>
    <artifactId>scala-maven-plugin</artifactId>
    <version>3.2.0</version>
    <executions>
        ...
    </executions>
    <configuration>
        <args>
            <arg>-target:jvm-1.8</arg>
            <arg>-encoding</arg>
            <arg>utf8</arg>
            <!-- Select the warnings you want to see from the Scala compiler -->
            <arg>-unchecked</arg>
            <arg>-deprecation</arg>
            <arg>-feature</arg>
            <arg>-Ywarn-numeric-widen</arg>
            <arg>-Ywarn-value-discard</arg>
            <arg>-Ywarn-dead-code</arg>
            <arg>-Ywarn-unused</arg>
        </args>
    </configuration>
</plugin>