Remove or Exclude WatchSource in sbt 1.0.x - scala

Question

Overview
After looking around the internet for a while, I have not found a good way to omit certain folders from being watched by sbt 1.0.x in a Play Framework application.
Solutions posted for older versions of sbt:
How to exclude a folder from compilation
How to not watch a file for changes in Play Framework
There are a few more, but all more or less the same.
And the release notes for 1.0.2 show that the += and ++= behavior was maintained, but everything else was dropped.
https://www.scala-sbt.org/1.x/docs/sbt-1.0-Release-Notes.html
Source code verifies: https://www.scala-sbt.org/1.0.4/api/sbt/Watched$.html
Would love to see if anyone using sbt 1.0.x has found a solution or workaround to this issue. Thanks!

Answer 1

Taking the approach of how SBT excludes managedSources from watchSources I was able to omit a custom folder from being watched like so:
watchSources := {
val directoryToExclude = "/Users/mgalic/sandbox/scala/scala-seed-project/src/main/scala/dirToExclude"
val filesToExclude = (new File(directoryToExclude) ** "*.scala").get.toSet
val customSourcesFilter = new FileFilter {
override def accept(pathname: File): Boolean = filesToExclude.contains(pathname)
override def toString = s"CustomSourcesFilter($filesToExclude)"
}
watchSources.value.map { source =>
new Source(
source.base,
source.includeFilter,
source.excludeFilter || customSourcesFilter,
source.recursive
)
}
},
Here we use PathFinder to get all the *.scala sources from directoryToExclude:
val filesToExclude = (new File(directoryToExclude) ** "*.scala").get.toSet
Then we create customSourcesFilter using filesToExclude, which we then add to every current WatchSource:
watchSources.value.map { source =>
new Source(
...
source.excludeFilter || customSourcesFilter,
...
)
}
Note the above solution is just something that worked for me, that is, I do not know what is the recommend approach of solving this problem.