How to get the changes since the last successful build in jenkins pipeline?

This is what I've used:

def listFilesForBuild(build) {
  def files = []
  currentBuild.changeSets.each {
    it.items.each {
      it.affectedFiles.each {
        files << it.path
      }
    }
  }
  files
}

def filesSinceLastPass() {
  def files = []
  def build = currentBuild
  while(build.result != 'SUCCESS') {
    files += listFilesForBuild(build)
    build = build.getPreviousBuild()
  }
  return files.unique()
}

def files = filesSinceLastPass()

Well I managed to cobble something together. I'm pretty sure you can iterate the arrays better but here's what I've got for now:

node('Android') {
  passedBuilds = []

  lastSuccessfulBuild(passedBuilds, currentBuild);

  def changeLog = getChangeLog(passedBuilds)
  echo "changeLog ${changeLog}"
}

def lastSuccessfulBuild(passedBuilds, build) {
  if ((build != null) && (build.result != 'SUCCESS')) {
      passedBuilds.add(build)
      lastSuccessfulBuild(passedBuilds, build.getPreviousBuild())
   }
}

@NonCPS
def getChangeLog(passedBuilds) {
    def log = ""
    for (int x = 0; x < passedBuilds.size(); x++) {
        def currentBuild = passedBuilds[x];
        def changeLogSets = currentBuild.rawBuild.changeSets
        for (int i = 0; i < changeLogSets.size(); i++) {
            def entries = changeLogSets[i].items
            for (int j = 0; j < entries.length; j++) {
                def entry = entries[j]
                log += "* ${entry.msg} by ${entry.author} \n"
            }
        }
    }
    return log;
  }

Based on the answer from CaptRespect i came up with the following script for use in the declarative pipeline:

def changes = "Changes:\n"
build = currentBuild
while(build != null && build.result != 'SUCCESS') {
    changes += "In ${build.id}:\n"
    for (changeLog in build.changeSets) {
        for(entry in changeLog.items) {
            for(file in entry.affectedFiles) {
                changes += "* ${file.path}\n"
            }
        }
    }
    build = build.previousBuild
}
echo changes

This is quite useful in stage->when->expression parts to run a stage only when certain files were changed. I haven't gotten to that part yet though, I'd love to create a shared library from this and make it possible to pass it some globbing patterns to check for.

EDIT: Check the docs btw, in case you want to delve a little deeper. You should be able to convert all the object.getSomeProperty() calls into just entry.someProperty.