anchor.diff:        await context.invoke("runTests", []);
       });
     }
  +
  +  if (tmpDir != null) {
  +    await tmpDir.delete(recursive: true);
  +  }
   }
  
positive.code:   var argz = opts.rest.skip(1).toList();
    context.setVariable("args", argz);
  
    var file = new File(opts.rest[0]);
  
    if (!await file.exists()) {
      print("ERROR: Unable to find script file '${file.path}'");
  
negative.code: import "dart:async";
  import "dart:convert";
  import "dart:io";
  
  import "package:args/args.dart";
  import "package:badger/compiler.dart";
  import "package:badger/eval.dart";
  
  Directory tmpDir;
  
  main(List<String> args) async {
    var argp = new ArgParser();
    argp.addFlag("test", negatable: false, abbr: "t", help: "Runs the script in a testing environment.");
  
    argp.addOption("compile", abbr: "c", allowed: [
      "tiny-ast",
      "ast",
  