code: function(paths) {
      return (
          gulp
          .src(paths.src.path)
          .pipe($.if(config.sourcemaps, $.sourcemaps.init({ loadMaps: true })))
          .pipe($.concat(paths.changeExtension(paths.output.name, '.js')))
          .pipe($.if(config.production, $.uglify()))
          .pipe($.if(config.sourcemaps, $.sourcemaps.write('.')))
          .pipe(gulp.dest(paths.output.baseDir))
      );
  }
docs: Combine javascript
  
  @param  {GulpPaths} paths
  @return {stream}