Question

在我正在编写的测试中，使用以下内部回调再次遇到异步地狱。我评论了不等待的回调。我使用async.series来编写函数，使用async.each来保持内部迭代同步。 Mocha compalins“done（）被多次调用” - 为什么代码不在等待？

describe('Report Generation (R subsystem)', function () {
  before(function (done) {
    //clear test files
    async.series([function (callback) { //1st
        console.log('Delete local test files');
        _.each(output_file_template, function (test_file) {
            if (fs.existsSync(__dirname + '/../reports/' + test_file + user_file_code + '.png')) {
                fs.unlinkSync(__dirname + '/../reports/' + test_file + user_file_code + '.png');
            };
        }); //..._.each
        callback();
    }, function (callback) { //2nd
        console.log('Delete remote test files');
        async.each(output_file_template, function (test_file, cb) {
            console.log(test_file);
            s3.del('reports/' + test_file + user_file_code + '.png', function (err, res) {
                console.log("Delete err", err);
                console.log("Delete result", res);
                cb();

            }, function(err) {callback(err);}); //s3.head

        }); //...async.each

    }], function (err, res) { //3rd
        done(); //this should tell the begin() clause to complete
    }); //...async.series

    }); //...before
    it('should not start this test until before() has finished!', function (done) {
        console.log("1st test here");

    });
});

Answer 1

，我可以看到，你正在使用3个函数的数组async.series，但最后没有控制函数。我假设，it('should not start...中的代码应该在那里。

所以（我认为）你的代码应该是这样的：

describe('My Test 1', function () {
    //clear test files
    async.series([
        function (callback) { //1st
            console.log('Delete local test files');
            ...
            callback();
        },
        function (callback) { //2nd
            console.log('Delete remote test files');

            async.each(
                output_file_template, 
                function (test_file, cb) {
                    console.log(test_file);
                    s3.del('reports/' + test_file + user_file_code + '.png', function (err, res) { //I can't get the following nested callback to wait
                        console.log("Delete err", err);
                        console.log("Delete result", res);
                        cb();
                    });  //...s3.head
                },
                function( err ) {  // this is the control function for async.each, so now it waits after all s3 have finished
                   callback( err );
                }
            ); //...s3.head
        },
        function (callback) { //3rd -> will be called now after the async.each (I don't think, you use it so can be deleted anyway)
            callback();
        }
    ],
    function( err, result ) {
        done();  // whatever this has to do with the last "it" -> here is the point, where the "before" is completely done
    }
});

我没有测试来源，所以也许里面有拼写错误，但我认为它显示了图片。

无法使Mocha before（）嵌套回调子句同步运行

1 个答案: