javascript - Function is returning the undefined value

Question

I have a function defined below. This function downloads files one by one and moves it to the directory named templates. In the end, it should return the length of the directory. The issue is, it returns the undefined value. I believe that I am messing up something. Can someone please help?

this.no_of_templates = function () {
    var num;
    this.download_files.each( async function (elem) {
        wait.waitForElementVisibility(elem);
        js.highlighterElement(elem);
        elem.click();
        browser.driver.wait(function(){
            var filesArray = glob.sync(dirPath + '**/*.+(xlsx|docx|pptx)');
            if(typeof filesArray !== 'undefined' && filesArray.length > 0){
                return filesArray;
            }
        }, 60000).then(function(filesArray){
            var filename = filesArray[0];
            fileSystem.moveFile(filename, process.cwd()+'/templates/');
            if(fileSystem.getAllDirFiles(process.cwd()+'/templates/').length >= 6){
                num = fileSystem.getAllDirFiles(process.cwd()+'/templates/').length;
                return false;
            }

        });
    });

    return num;
}

getAllDirFiles() is defined as

this.getAllDirFiles = function (dirPath, arrayOfFiles) {
    var files = fs.readdirSync(dirPath);

    arrayOfFiles = arrayOfFiles || [];

    files.forEach(function (file) {
        if (fs.statSync(dirPath + "/" + file).isDirectory()) {
            arrayOfFiles = getAllDirFiles(dirPath + "/" + file, arrayOfFiles);
        } else {
            arrayOfFiles.push(file);
        }
    })
    return arrayOfFiles;
}

Function returns undefined value.

it('test if templates are downloadable', () => {
var templates = bt.no_of_templates();
expect(templates).toBe(6);

});

question from:https://stackoverflow.com/questions/65867677/function-is-returning-the-undefined-value

Answer 1

Because you are using async function in each, it won't wait for they finished.

try this:

this.no_of_templates = async function () {
    var num;
    var holdon = this.download_files.map( async function (elem) {
        wait.waitForElementVisibility(elem);
        js.highlighterElement(elem);
        elem.click();
        return browser.driver.wait(function(){
            var filesArray = glob.sync(dirPath + '**/*.+(xlsx|docx|pptx)');
            if(typeof filesArray !== 'undefined' && filesArray.length > 0){
                return filesArray;
            }
        }, 60000).then(function(filesArray){
            var filename = filesArray[0];
            fileSystem.moveFile(filename, process.cwd()+'/templates/');
            if(fileSystem.getAllDirFiles(process.cwd()+'/templates/').length >= 6){
                num = fileSystem.getAllDirFiles(process.cwd()+'/templates/').length;
                return false;
            }

        });
    });
    await Promise.all(holdon)
    return num;
}

test:

bt.no_of_templates().then(num => {
  expect(num).toBe(6);
});

just need to change to match your framework, it seems not pure javascript.

---

And i found some problem in code. why are you count files in every download job?