gulp watch 执行出错（watchtaskisnot啊fucntion）

Question

var gulp=require("gulp");

var uglify=require("gulp-uglify");

gulp.task("uglify",function(){

gulp.src("js/*.js").pipe(uglify()).pipe(gulp.dest("js-uglify"));

})

gulp.task('auto1',function(){

    gulp.watch("js/*.js",['uglify']);

})

运行结果