Scala 3 support

[carlosedp]

Are there plans to support Scala 3?

I tried with:

      <plugin>
        <groupId>io.github.evis</groupId>
        <artifactId>scalafix-maven-plugin_2.13</artifactId>
        <version>0.1.8_0.11.0</version>
        <configuration>
          <commandLineArgs>--scala-version=${scala.version}</commandLineArgs>
        </configuration>
      </plugin>

But still got syntax errors from running on a Scala 3 project using the new syntax like:

[INFO] --- scalafix:0.1.8_0.11.0:scalafix (default-cli) @ scala3-quarkus-quickstart ---
[INFO] Processing[main]: /Users/cdepaula/repos/scala/scala3-quarkus-quickstart/src/main/scala
[INFO] Processing[test]: /Users/cdepaula/repos/scala/scala3-quarkus-quickstart/src/test/scala
info: Processing ( 0/13) /Users/cdepaula/repos/scala/scala3-quarkus-quickstart/src/main/scala/org/acme/GreetingResource.scala
/Users/cdepaula/repos/scala/scala3-quarkus-quickstart/src/main/scala/org/acme/GreetingResource.scala:7:23: error: ; expected but : found
class GreetingResource:
                      ^
info: Processing ( 1/13) /Users/cdepaula/repos/scala/scala3-quarkus-quickstart/src/main/scala/org/acme/kafka/ArticleModels.scala
/Users/cdepaula/repos/scala/scala3-quarkus-quickstart/src/main/scala/org/acme/kafka/ArticleModels.scala:9:4: error: ; expected but : found
  ):

[carlosedp]

Hi @evis .... any tips on how I can override the Scala version used by Scalafix?

Running with debug, I see that it picks the cmdline flag but doesn't use it (on the arguments):

[DEBUG] Loading mojo io.github.evis:scalafix-maven-plugin_2.13:0.1.8_0.11.0:scalafix from plugin realm ClassRealm[plugin>io.github.evis:scalafix-maven-plugin_2.13:0.1.8_0.11.0, parent: java.net.URLClassLoader@255316f2]
[DEBUG] Configuring mojo execution 'io.github.evis:scalafix-maven-plugin_2.13:0.1.8_0.11.0:scalafix:default-cli' with basic configurator -->
[DEBUG]   (f) commandLineArgs = [--scala-version=3.3.3]
[DEBUG]   (f) mainSourceDirectories = []
[DEBUG]   (f) mode = IN_PLACE
[DEBUG]   (f) project = MavenProject: org.acme:scala3-quarkus-quickstart:1.0.0-SNAPSHOT @ /Users/cdepaula/repos/scala/scala3-quarkus-quickstart/pom.xml
[DEBUG]   (f) skip = false
[DEBUG]   (f) skipMain = false
[DEBUG]   (f) skipTest = false
[DEBUG]   (f) testSourceDirectories = []
[DEBUG] -- end configuration --
[INFO] Processing[main]: /Users/cdepaula/repos/scala/scala3-quarkus-quickstart/src/main/scala
[INFO] Processing[test]: /Users/cdepaula/repos/scala/scala3-quarkus-quickstart/src/test/scala
[DEBUG] arguments = Right(ScalafixArgumentsImpl({"rules": [], "files": ["/Users/cdepaula/repos/scala/scala3-quarkus-quickstart/src/main/scala", "/Users/cdepaula/repos/scala/scala3-quarkus-quickstart/src/test/scala"], "config": null, "check": false, "stdout": false, "diff": false, "diffBase": null, "syntactic": false, "triggered": false, "verbose": false, "help": false, "version": false, "classpath": "<classpath>", "sourceroot": null, "semanticdbTargetroots": [], "autoClasspath": false, "autoClasspathRoots": [], "scalacOptions": ["-Wunused:all", "-feature", "-deprecation", "-Ysemanticdb"], "scalaVersion": "2.13.13", "bash": false, "zsh": false, "exclude": [], "toolClasspath": "<classloader>", "charset": "UTF-8", "noSysExit": false, "noStaleSemanticdb": false, "settings": {}, "outFrom": null, "outTo": null, "autoSuppressLinterErrors": false, "cwd": "/Users/cdepaula/repos/scala/scala3-quarkus-quickstart", "nonInteractive": false, "out": "<stdout>", "ls": "find", "callback": "scalafix.internal.interfaces.MainCallbackImpl$$anon$1@7db47323"}))
...

[evis]

@carlosedp could you give me an example of Scala 3 project built with Maven? I wasn't able to quickly create compiling project from scratch.

Sorry for such a long delay in responding :(

[carlosedp]

Hi Evgeny, thanks for your time! I've set a sample project with Scalafix and Scalafmt using Scala 3 at https://github.com/carlosedp/scala3-maven.

A couple of things I've noticed:

• I tried overriding the command line arguments as you can see in the pom.xml but it didn't do anything (tried with -Dscalafix.command.line.args=... as well but got the same results.
• When I try to run the scalafix:scalafix goal, I get error: SemanticDB not found: src/main/scala/org/acme/Hello.scala... I have to do a ./mvnw clean compile test-compile before running that goal (since I have -Ysemanticdb in my scala plugin args). It would be nice if scalafix could override this in some way and compile it with semanticDB before.

[bjaglin]

I haven't run anything as I don't know/use maven, but it looks like

scalafix-maven-plugin/src/main/scala/io/github/evis/scalafix/maven/plugin/params/ProjectDependenciesParam.scala

Line 24 in 0983476

}).withScalaVersion(scalaLibrary.map(_.getVersion))

(which is likely 2.13 since Scala 3 doesn't have its own standard library) takes precedence over your custom CLI args, given

• the order that that wrapper follows to instantiate the Scalafix instance
  

  scalafix-maven-plugin/src/main/scala/io/github/evis/scalafix/maven/plugin/ScalafixArgumentsBuilder.scala

  Lines 67 to 74 in 0983476

  	.withParsedArguments(parsedArguments.asJava)
  	.withPrintStream(printStream)
  	.withClasspath(classpath.asJava)
  	.withSourceroot(sourceroot)
  	.withMainCallback(mainCallback)
  	.withCharset(charset)
  	.withScalaVersion(scalaVersion)
  	.withScalacOptions(scalacOptions.asJava)

• the silent "last wins" semantics of ScalafixArgumentsImpl#withScalaVersion()

[evis]

I'm sick, I'll deal with this issue when I'm healthy.

[carlosedp]

Sure, hope tou get better soon!
Best wishes!

[evis]

@bjaglin thanks for the tip! It helped to fix it :)

@carlosedp I've initiated release 0.1.9_0.12.1 with the fix, it will become available in Maven Central soon. Thanks for your report!

[evis]

Though, semanticdb rules don't work yet... I guess, I should build it for Scala 3 too, gonna work on it.

[evis]

Oh, I forgot to compile sources before running scalafix. semanticdb rules work too, nevermind, closing it again

[bjaglin]

Besides the fix, I would still recommend withParsedArguments() to be invoked last, to allow users to override what the plugin infers if/when needed. That's what sbt-scalafix does.

[carlosedp]

Thanks a lot! Just added it to my project and worked perfectly!