anchor.diff:    return lines.join('\n');
   }
   
  -void compileWebFrontEnd() async {
  +void compileWebFrontEnd({bool devMode = false}) async {
     String sdkBinDir = path.dirname(Platform.resolvedExecutable);
     String dart2jsPath = path.join(sdkBinDir, 'dart2js');
   
  -  const minified = true;
  -
     // dart2js -m -o output source
     Process process = await Process.start(dart2jsPath, [
  -    if (minified) '-m',
  +    devMode ? '-O1' : '-m',
       '--no-frequency-based-minification',
       '-o',
       javascriptOutput.path,
  
positive.code:     fail('Please run this tool from the root of the sdk repo.');
    }
  
    bool verify = args.isNotEmpty && args.first == '--verify';
  
    if (verify) {
      verifyResourcesGDartGenerated();
    } else {
      await compileWebFrontEnd();
  
      print('');
  
  
negative.code: import 'dart:io';
  import 'dart:math' as math;
  
  import 'package:args/args.dart';
  import 'package:crypto/crypto.dart';
  import 'package:path/path.dart' as path;
  
  void main(List<String> args) async {
    var argParser = ArgParser()
      ..addFlag('verify', negatable: false)
      ..addFlag('dev', negatable: false)
      ..addFlag('help', negatable: false);
    var argResults = argParser.parse(args);
    if (argResults['help'] == true) {
      fail('''
  usage: dart pkg/analysis_server/tool/nnbd_migration/generate_resources.dart [--verify]
  
  