我相信你的问题在于这个任务:
grunt.registerTask('prepare-dist', 'Creates folders needed for distribution', function() {
var folders = ['dist/css/images', 'dist/imgs/icons'];
for (var i in folders) {
var done = this.async();
grunt.util.spawn({ cmd: 'mkdir', args: ['-p', folders[i]] }, function(e, result) {
grunt.log.writeln('Folder created');
done();
});
}
});
如果你有多个文件夹,async() 和done() 都会被调用多次。异步被实现为一个简单的标志(true/false),并且意味着被调用一次。第一个 did() 调用允许运行任何后续任务。
有很多方法可以将调用移至 async 并完成循环。快速谷歌搜索类似的内容:nodejs how to callback when a series of async tasks are complete
会给你一些额外的选择。几个快速(且肮脏)的例子:
// Using a stack
(function() {
var work = ['1','2','3','4','5']
function loop(job) {
// Do some work here
setTimeout(function() {
console.log("work done");
work.length ? loop(work.shift()) : done();
}, 500);
}
loop(work.shift());
function done() {
console.log('all done');
}
})();
-- or --
// Using a counter (in an object reference)
(function() {
var counter = { num: 5 }
function loop() {
// Do some work here
setTimeout(function() {
--counter.num;
console.log("work done");
counter.num ? loop() : done();
}, 500);
}
loop();
function done() {
console.log('all done');
}
})();