Q.all為非承諾和承諾組合

Question

我在做什么：我先輸入svn網址數組，然后對所有網址執行簽出操作。

問題：當被調用函數未返回承諾時，我無法使Q.all失敗。

注意：使用Q版本2.x

源代碼：

const SvnSpawn = require("svn-spawn");
const Q = require("q");
const validations = require("./validations.js");
const client = new SvnSpawn();

/**
 * Silently checkout the svn content to the specified folder
 * @param {String} svnUrl - URL for the svn checkout
 * @param {String} destPath - Path to the destination folder
 * @returns {void}
 * @private
 */
function checkout(svnUrl, destPath){
    if(validations.isValidString(svnUrl) && validations.isValidString(destPath)){
        const deferred = Q.defer();

        client.cmd(["export", "--force", "--quiet", svnUrl, destPath], (err) => {
            if(err){
                deferred.reject(err);
            }
            else{
                deferred.resolve();
            }
        });
        return deferred.promise;
    }
    else{
        return new Error("SVN: svn url or destination path are not valid");
    }
}

/**
 * Checkout all the svn dependencies
 * @param {String[]} svnDependencies - Collection of SVN dependencies
 * @param {String} workingFolder - Path to the working folder
 * @returns {void}
 * @public
 */
function svnCheckout(svnDependencies, workingFolder){
    const deferred = Q.defer();

    Q.all(svnDependencies.map((svnUrl) =>
            checkout(svnUrl, workingFolder)
        ))
        .then((response) => {
            deferred.resolve();
        })
        .catch((err) => {
            deferred.reject(err);
        });

    return deferred.promise;
}

module.exports.checkout = svnCheckout;

上面的代碼是如何使用的：

const svn = require("./lib/util/svnOperations");

svn.checkout([
    1,
    "http://<url>",
    "http://<url>"
], "./working")
.then(() => {
    console.log("Done");
})
.catch((err) => {
    console.error(err);
})
.done();

預期：上面的代碼應導致錯誤，但會以Done退出。

Answer 1

讓您的代碼在失敗時返回拒絕的承諾，

return Q.reject(new Error("SVN: svn url or destination path are not valid"));