Obfuscating going wrong - Not same result always #34

var preprocess = require('gulp-preprocess'),
concat = require('gulp-concat'),
javascriptobfuscator = require('gulp-javascript-obfuscator');


gulp.task('app', function() {
    return gulp.src('./js/app.js')
      .pipe(preprocess({
          context: {
            HOST: host,
            VER: ver
          }
        }))
        .pipe(concat('app.js'))
        .pipe(javascriptobfuscator({
          reservedStrings:['loadScript','loadCss']
        }))
        .pipe( gulp.dest('dist/target/js'));
  });