从函数中的量角器promise中返回一个值

Question

我正试图从页面获取文本，然后在规范中进一步使用该文本来断言另一个元素。

我已经粘贴了一个非常简单的规范，你可以运行，如果函数的return语句在一个量角器promise promise return txt;你就不能从函数返回一个值return txt; （第24行）......

describe('My Test', function () {
    var tempVariable;

    it('should go get some text from the page', function () {
        browser.get('https://angularjs.org/');
        tempVariable = getTextFromElement();    //it appears javascript immediately sets this variable before waiting for protractor to return the value
    });

    it('should do some random other stuff', function () {
        element.all(by.cssContainingText('a', 'Learn')).get(0).click();
        element.all(by.cssContainingText('a', 'Case Studies')).get(0).click();
        element.all(by.cssContainingText('a', ' Home')).get(0).click();
    });

    it('should be able to use the text from the first page in this test', function () {
        console.log('\ntempVariable: ' + tempVariable);    //this is undefined!
        expect(typeof tempVariable).not.toBe('undefined', 'failed: tempVariable was undefined!');
    });
});

function getTextFromElement() {
    $('a.learn-link').getText().then(function (txt) {
        console.log('\nInitial text:   ' + txt);
        return txt;     //how do we return this so it's available to other 'it' blocks?
    });
}

在@alecxe回答和我的评论之后更新了代码片段。

我试图从页面上的各种文本构造一个对象，并在稍后的页面中将其返回到断言...

function getRandomProductFromList() {
    var Product = function (line, name, subname, units) {
        this.line       = line;
        this.name       = name;
        this.subname    = subname;
        this.units      = units;
    };

    var myProduct = new Product();

    myProduct.line = 'Ford';
    myProduct.units = 235;

    //select a random product on the page and add it to 'myProduct'
    var allProducts = element.all('div.product');
    allProducts.count().then(function (count) {
        var randomIndex = Math.floor(Math.random() * count);
        var productName = allProducts.get(randomIndex);

        productName.getText().then(function (prodName) {
            myProduct.name = prodName;
            productName.click();
        });
    });

    //If a sub-product can be chosen, select it and add it to 'myProduct'
    var subproduct = $('div.subproduct');
    subproduct.isDisplayed().then(function (subProductExists) {
        if (subProductExists) {
            subproduct.getText().then(function (subProductName) {
                myProduct.subname = subProductName;
            });
            subproduct.click();
        }
    }, function (err) {});

    return myProduct;
}

Answer 1

首先，你没有从函数返回任何东西 ：

function getTextFromElement() {
    return $('a.learn-link').getText();
}

现在，此函数将返回您在使用之前需要解决的承诺 ：

it('should be able to use the text from the first page in this test', function () {
    tempVariable.then(function (tempVariableValue) {
        console.log('\ntempVariable: ' + tempVariableValue);    
        expect(typeof tempVariableValue).not.toBe('undefined', 'failed: tempVariable was undefined!');
    });
});

另外，为了确定是否定义了变量，我将使用来自jasmine-matchers toBeDefined() ：

expect(tempVariableValue).toBeDefined();

Answer 2

感谢@alecxe让我从右脚开始。

我发现我现在用相当多的解决方案看完这个 。

通过引用传递对象，您可以动态添加属性并在以后的规范中使用它们。

例：

describe('My Test', function () {
    var tempObject = {};

    it('should go get some text from the page', function () {
        browser.get('https://angularjs.org/');
        getTextFromElement(tempObject);    //pass an object by reference to populate with page text
    });

    it('should do some random other stuff', function () {
        $('div.someDiv').click();
    });

    it('should be able to use the text from the first page in this test', function () {
        console.log(tempObject.textFromFirstPage); //works!
    });
});

function getTextFromElement(tempObject) {
    $('a.some-link').getText().then(function (txt) {
        tempObject.textFromFirstPage = txt;
    });
}

Answer 3

以上都不适合我。 这对我有用：

    var item = element.all(by.xpath("some xpath here"));


    this.methodToGetTheText = function () {
       return Promise.resolve(item.getText().then(function (text) {
           return text;
       }));
    }

Answer 4

你打电话methodToGetTheText().then(从你的规范呢？值内.then()函数应该包含您的实际网页的文本