864296 - Marionette webelement.find_element(locator) returns values even if the webelement is no longer present on the page

Status: RESOLVED FIXED

(Remote Protocol :: Marionette, defect)

Description

[Florin Strugariu [:Bebe]]

Attachment: Test for the bug

This is a little complicated.

1. Store a webelement in a variable
2. delete the webelement from the page
3. call the stored webelement from the var and check it's properties 

Espected:
3. calling properties for a webelement that doesn’t exist should return a exception NoSuchElementException or something similar

Actual:
3. calling the webelement returns false positive data


Here is the code:

        #store a web element in a var
        element = self.marionette.find_element(*self._favorite_list_locator)


        # check some basic properties
        print element.is_displayed()
        print element.text
        print element.find_element(*self._remove_locator).is_displayed()
        self.assertTrue(element.find_element(*self._remove_locator))
        
        print "======================"
        print "delete the element"

        #delete the web element
        self.marionette.tap(element.find_element(*self._remove_locator))
        time.sleep(2)

        print "element is deleted"
        print "====================="

        # call the same properties. This methods should return exceptions
        print element.is_displayed() 
        print element.text
        print element.find_element(*self._remove_locator).is_displayed()
        self.assertTrue(element.find_element(*self._remove_locator))

        #searching for the same element again returns a error
        self.marionette.find_element(*self._favorite_list_locator)


I have added in the attachment the full test

Comment 1

[Florin Strugariu [:Bebe]]

Webdriver returns a StaleElementReferenceException

selenium.common.exceptions.StaleElementReferenceException: Message: u'Element is no longer attached to the DOM'

selenium test: https://gist.github.com/bebef1987/5434882

Comment 2

[Malini Das [:mdas] - Away, not checking bugmail]

http://hg.mozilla.org/mozilla-central/file/ea3ffdbddc53/testing/marionette/marionette-elements.js#l108

We check if the element is no longer a part of the document, but I suppose if GC hasn't run yet, perhaps it still is part of the document. The way the element is being removed is :

https://github.com/mozilla-b2g/gaia/blob/master/apps/fm/js/fm.js#L588

that is, we should be checking its parentNode to see if it is not null.

Comment 3

[Jonathan Griffin (:jgriffin)]

Attachment: Check for detached elements,

Comment 4

[Jonathan Griffin (:jgriffin)]

try: https://tbpl.mozilla.org/?tree=Try&rev=abd143557b62

Comment 5

[Malini Das [:mdas] - Away, not checking bugmail]

Comment on attachment 743956 [details] [diff] [review]
Check for detached elements,

Review of attachment 743956 [details] [diff] [review]:
-----------------------------------------------------------------

Ah, cool, this should do it

Comment 6

[Jonathan Griffin (:jgriffin)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/d846f95bc761

Comment 7

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/d846f95bc761

Comment 8

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-b2g18/rev/7877c7c2cbee

Comment 9

[Jonathan Griffin (:jgriffin)]

https://hg.mozilla.org/releases/mozilla-b2g18_v1_0_1/rev/dd13a6ae0117