Use element by css to check if element exists in Protractor

问题

In a protractor end to end test, I want to check if an element exist using element(by.css(...)), my code:

var myElement = element(by.css('.elementClass'));
expect(myElement).toBeUndefined;

This test fails, it says:

    Expected { locator_ : { using : 'css selector', value : 'div[ng-switch-
    when="resultNav"]' }, parentElementFinder_ : null, opt_actionResult_ :
    undefined, opt_index_ : undefined, click : Function, sendKeys : Function, 
getTagName : Function, getCssValue : Function, getAttribute : Function, getText
 : Function, getSize : Function, getLocation : Function, isEnabled : Function, 
isSelected : Function, submit : Function, clear : Function, isDisplayed : 
Function, getOuterHtml : Function, getInnerHtml : Function, toWireValue : 
Function } to be undefined.

After that I tried to use a promise:

element(by.css('.elementClass')).then( functtion(data) {
    expect(data.getText()).toBeUndefined();
});

This results in an error:

Error: No element found using locator By.CssSelector(...)

Yes, I know that no element will be found, but how can I create a working test using element(by.css(...))?

Does anyone know how to achieve this? or is element(by.css()) not the method to use here?

回答1:

You can test whether the element is present with isPresent. Here are the protractor docs for the isPresent function.

So, your code would be something like:

var myElement = element(by.css('.elementClass'));
expect(myElement.isPresent()).toBeFalsy();

回答2:

You need to test if the element is not present:

expect(element(by.css('.elementClass')).isPresent()).toBe(false);

来源：https://stackoverflow.com/questions/28024342/use-element-by-css-to-check-if-element-exists-in-protractor