Function to remove specific lines from a file (and return an ArrayList)

In combination with listToMD5(), I wrote a Groovy utils function to remove specific lines from a file and return an ArrayList:

  // Function to filter certain lines from a file and return an ArrayList
  // Remember that the index starts at 0 in Groovy
  public static ArrayList excludeLines(String inFilePath, linesToExclude) {
      def inputLines = new File(inFilePath).readLines()
      if (linesToExclude.size() >= 0){
          Set<Integer> setOfLines = (0..inputLines.size()-1) as Set
          def newSetOfLines = setOfLines.minus(linesToExclude)
          return inputLines.getAt(newSetOfLines)
      }
      else {
          return inputLines
      }
  }

Test usage:

{ assert listToMD5(UTILS.excludeLines("$outputDir/foo.txt", [1,3,7,8,9,11,12,13,14,15,20,21])) == listToMD5(UTILS.excludeLines("some/other/local.txt", [1,3,7,8,9,11,12,13,14,15,20,21])) },
# or to compare 
{ assert snapshot(
    listToMD5(UTILS.excludeLines("$outputDir/foo.txt", [1,3,7,8,9,11,12,13,14,15,20,21]))
  ).match() }

The Groovy code could probably be improved, still, it might be useful this as an nft-utils function.

Start by locating the existing nft-utils entry points, especially the UTILS function collection and listToMD5(). Add an excludeLines utility based on the described usage, returning the remaining file lines; verify the two example comparisons produce matching results.