量角器:'wait'不适用于"element.all"

我写了Protractor自动化测试并面临一个问题.Wait命令实际上并不等待其中一个数组元素.请参阅下面的示例:我尝试在导航到网页后等待第一个元素.

var category = element.all(by.repeater('category in listCtrl.categories'));
var category2 = $$('.category-name.custom-tooltip-link.ng-binding');
var EC = protractor.ExpectedConditions;

describe('wait for the first category', function() {

    it('wait', function() {
        browser.get('http://www.deep.mg/');

        browser.wait(EC.visibilityOf(category.get(0)), 20000);

        browser.wait(EC.visibilityOf(category2.get(0)), 20000);
    });
});

但测试失败,出现以下错误:Failed: Index out of bound. Trying to access element at index: 0, but there are only 0 elements that match locator by.repeater("category in listCtrl.categories").

错误不依赖于定位器类型,因为两者都出现:"by.repeater"和"by.css".选择器没问题,添加'sleep'命令后测试通过:

var category = element.all(by.repeater('category in listCtrl.categories'));
var category2 = $$('.category-name.custom-tooltip-link.ng-binding');
var EC = protractor.ExpectedConditions;

describe('wait for the first category', function() {

    it('wait', function() {
        browser.get('http://www.deep.mg/');

        browser.sleep(15000);

        browser.wait(EC.visibilityOf(category.get(0)), 20000);

        browser.wait(EC.visibilityOf(category2.get(0)), 20000);

        category.count().then(function(count1) {
            console.log(count1);  //count returns 5, which means there are actually elements in array
        });

        category2.count().then(function(count2) {
            console.log(count2);
        });
    });
});

此外,超时参数没有帮助,它只是忽略它并立即失败.

那么问题是如何等待数组的某个元素？我错过了什么吗？谢谢.

创建自定义预期条件以等待数组中元素的数量大于0:

function presenceOfAll(elementArrayFinder) {
    return function () {
        return elementArrayFinder.count(function (count) {
            return count > 0;
        });
    };
}

用法:

browser.wait(presenceOfAll(category), 10000);
browser.wait(presenceOfAll(category2), 10000);

适合我.