Gulp excludes the use of files

  node.js, question
var gulp = require('gulp');
 var del = require('del');
 var uglify = require('gulp-uglify');
 var gutil = require('gulp-util');
 var colors = require('colors/safe');
 var gulpif = require('gulp-if');
 gulp.task('build', function () {
 Gutil.log( ('start compressing js ...');
 gulp.src(['*.js', '!  gulpfile.js'])
 .pipe(gulpif('!  lang-*.js', uglify()))
 gulp.task('clean', function () {
 Gutil.log( ('start emptying files');

The original intention was to compress the folders under the current directory, but to exclude js files beginning with lang, but I checked the results and found that js files beginning with lang were also compressed. why is this?

Src array parameter! lang-*.js