SBT How get filename in folder with match? - scala

Question

I need find filename in folder (in build.sbt), and add in artifact list.
//in build.sbt
val myZipTask = taskKey[File]("return the bundle:dist-zip file")
myZipTask := {
val filesArray = new java.io.File("/target/bundle").listFiles()
//here need to find the file name by coincidence and convert to a string
file(fileName)
}; addArtifact( Artifact("bundle", "zip", "zip"), myZipTask)
I tried this option
//in build.sbt
val myZipTask = taskKey[File]("return the bundle:dist-zip file")
myZipTask := {
import java.io.File
def getListOfFiles(dir: String): List[String] = {
val file = new File(dir)
file.listFiles.filter(_.isFile)
.filter(_.getName.startsWith("startName"))
.map(_.getPath).toList
}
getListOfFiles("/target/bundle")
}; addArtifact( Artifact("bundle", "zip", "zip"), myZipTask)
And sbt return me error:
build.sbt: error: type mismatch;
found : List[String]
required: sbt.File
(which expands to) java.io.File
getListOfFiles("/target/bundle")
^

Answer 1

Check the documentation on Path Finders:
val finder: PathFinder = target.value / "bundle"
You can add * "startName*" if you want to filter by prefix. If you call finder.get, it will return you a Seq[File], so this is what you wanted from your getListOfFiles.
But the problem with your code is that you need to return one file, not a list. You could either output an error if the file doesn't exist:
finder.get.headOption.getOrElse {
sys.error("Couldn't find bundle dist-zip file")
}
or change you task type to Option[File], return finder.get.headOption and add the artifact only if the file is there:
myZipTask.value.foreach { zipFile =>
addArtifact(Artifact("bundle", "zip", "zip"), zipFile)
}
This foreach could work even for multiple files if that's an option in your usecase.