为什么在没有执行'if'的Promise之后阻塞？

Question

我对异步编程相当陌生，并试图理解为什么执行永远不会进入包含“if”的承诺之后链接的“then”块。有人可以帮忙吗？

var uploadResourceToView = function (edit) {
    var promises = [];

    for (var i = 0; i < inputConfig.length; i++) {
        promises.push(new Promise(function (resolve, reject) {
            var name = 'hey';

            new Promise(function (resolve) {
                if (i == 0) {
                    return new pTree().renamePage('Home', name);
                } else {
                    return edit.addPage(name, '3D')
                }
            })
            // subsequent then()s are never executed 
            .then(function () {
                console.log('why am I not been executed ? ');
                return edit.addObject(object)
            })
            .then(function () {
                return edit.addResource('test resource', true);
            })
            .then(resolve, reject);
        });
    }

    return Promise.all(promises);
}

Answer 1

因为你从不打电话给resolve 或reject 来表达你内心的承诺。您传递给Promise 构造函数的执行器函数的返回值被完全忽略。要解决承诺，请调用 new Promise 传递给执行程序的 resolve 或 reject 回调。

---

就实际使整个功能正常工作而言，我猜renamePage 和addPage 会返回承诺。如果是这样，请直接使用它们，无需在该函数中的任何位置使用new Promise：

var uploadResourceToView = function (edit) {
    var promises = [];

    for (var i = 0; i < inputConfig.length; i++) {
        var name = 'hey';
        var inner = i == 0 ? new pTree().renamePage('Home', name) : edit.addPage(name, '3D');
        promises.push(inner
            .then(function () {
                console.log('why am I not been executed ? ');
                return edit.addObject(object)
            })
            .then(function () {
                return edit.addResource('test resource', true);
            })
        });
    }

    return Promise.all(promises);
}

更多：What is the explicit promise construction antipattern and how do I avoid it?