Build stages in Jenkins only when specific files are changed but use a function

Question

I want to update my Jenkins pipeline in way that certain stages are only build when some specific files are changed (git is already integrated in the pipeline). I found a promising solution on this site, which would go like this for my use case (this code run successful):

stage("TEST STAGE 1") {
  when {
    anyOf { changeset "*dir1/*"; changeset "*dir2/*"; changeset "*somefile" }
  }
  steps {
    // Do stuff
  }
}

But I have more stages (TEST STAGE 2 and TEST STAGE 3) which should also be triggered only when these files are changed. To avoid writing the same code over and over (which would be bad practice), I implemented a function (I got the code from here):

def runStage(changeset) {
  return {
    changeset ==~ ("*dir1/*"||"*dir2/*"||"*somefile")
  }
}

I call this function in the TEST stages (also TEST 2 and 3):

stage("TEST STAGE 1") {
  when {
    expression{ runStage(changeset) }
  }
  steps {
    // Do stuff
  }
}

But now my pipeline fails when entering the first TEST stage. I get this error:

hudson.remoting.ProxyException: groovy.lang.MissingPropertyException: No such property: changeset for class: WorkflowScript

Do you have an idea what I am doing wrong?

Answer 1

I found a solution. This is my function:

def runStage() {
   CHANGE_SET = sh (
      script: 'git log -2 --name-only --oneline --pretty="format:"',
      returnStdout: true
   ).trim()
   echo "Current changeset: ${CHANGE_SET}"
   return (CHANGE_SET ==~ "(.*)dir1(.*)|(.*)dir2(.*)|(.*)somefile")
}

I call it in my pipeline stage like this:

stage("TEST STAGE 1") {
   when { 
      expression { runStage() }
   }
   steps {
      //stuff
   }
}

I would have prefered using changeset in the when block instead of git log, but it looks like it can't be done for my case.