nextcloud/tests/acceptance/features/core/ElementFinder.php

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<?php
/**
*
* @copyright Copyright (c) 2017, Daniel Calviño Sánchez (danxuliu@gmail.com)
*
* @license GNU AGPL version 3 or any later version
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
/**
* Command object to find Mink elements.
*
* The element locator is relative to its ancestor (either another locator or an
* actual element); if it has no ancestor then the base document element is
* used.
*
* Sometimes an element may not be found simply because it has not appeared yet;
* for those cases ElementFinder supports trying again to find the element
* several times before giving up. The timeout parameter controls how much time
* to wait, at most, to find the element; the timeoutStep parameter controls how
* much time to wait before trying again to find the element. If ancestor
* locators need to be found the timeout is applied individually to each one,
* that is, if the timeout is 10 seconds the method will wait up to 10 seconds
* to find the ancestor of the ancestor and, then, up to 10 seconds to find the
* ancestor and, then, up to 10 seconds to find the element. By default the
* timeout is 0, so the element and its ancestor will be looked for just once;
* the default time to wait before retrying is half a second.
*
* In any case, if the element, or its ancestors, can not be found a
* NoSuchElementException is thrown.
*/
class ElementFinder {
/**
* Finds an element in the given Mink Session.
*
* @see ElementFinder
*/
private static function findInternal(\Behat\Mink\Session $session, Locator $elementLocator, $timeout, $timeoutStep) {
$element = null;
$selector = $elementLocator->getSelector();
$locator = $elementLocator->getLocator();
$ancestorElement = self::findAncestorElement($session, $elementLocator, $timeout, $timeoutStep);
$findCallback = function () use (&$element, $selector, $locator, $ancestorElement) {
$element = $ancestorElement->find($selector, $locator);
return $element !== null;
};
if (!Utils::waitFor($findCallback, $timeout, $timeoutStep)) {
$message = $elementLocator->getDescription() . " could not be found";
if ($timeout > 0) {
$message = $message . " after $timeout seconds";
}
throw new NoSuchElementException($message);
}
return $element;
}
/**
* Returns the ancestor element from which the given locator will be looked
* for.
*
* If the ancestor of the given locator is another locator the element for
* the ancestor locator is found and returned. If the ancestor of the given
* locator is already an element that element is the one returned. If the
* given locator has no ancestor then the base document element is returned.
*
* The timeout is used only when finding the element for the ancestor
* locator; if the timeout expires a NoSuchElementException is thrown.
*
* @param \Behat\Mink\Session $session the Mink Session to get the ancestor
* element from.
* @param Locator $elementLocator the locator for the element to get its
* ancestor.
* @param float $timeout the number of seconds (decimals allowed) to wait at
* most for the ancestor element to appear.
* @param float $timeoutStep the number of seconds (decimals allowed) to
* wait before trying to find the ancestor element again.
* @return \Behat\Mink\Element\Element the ancestor element found.
* @throws NoSuchElementException if the ancestor element can not be found.
*/
private static function findAncestorElement(\Behat\Mink\Session $session, Locator $elementLocator, $timeout, $timeoutStep) {
$ancestorElement = $elementLocator->getAncestor();
if ($ancestorElement instanceof Locator) {
try {
$ancestorElement = self::findInternal($session, $ancestorElement, $timeout, $timeoutStep);
} catch (NoSuchElementException $exception) {
// Little hack to show the stack of ancestor elements that could
// not be found, as Behat only shows the message of the last
// exception in the chain.
$message = $exception->getMessage() . "\n" .
$elementLocator->getDescription() . " could not be found";
if ($timeout > 0) {
$message = $message . " after $timeout seconds";
}
throw new NoSuchElementException($message, $exception);
}
}
if ($ancestorElement === null) {
$ancestorElement = $session->getPage();
}
return $ancestorElement;
}
/**
* @var \Behat\Mink\Session
*/
private $session;
/**
* @param Locator
*/
private $elementLocator;
/**
* @var float
*/
private $timeout;
/**
* @var float
*/
private $timeoutStep;
/**
* Creates a new ElementFinder.
*
* @param \Behat\Mink\Session $session the Mink Session to get the element
* from.
* @param Locator $elementLocator the locator for the element.
* @param float $timeout the number of seconds (decimals allowed) to wait at
* most for the element to appear.
* @param float $timeoutStep the number of seconds (decimals allowed) to
* wait before trying to find the element again.
*/
public function __construct(\Behat\Mink\Session $session, Locator $elementLocator, $timeout, $timeoutStep) {
$this->session = $session;
$this->elementLocator = $elementLocator;
$this->timeout = $timeout;
$this->timeoutStep = $timeoutStep;
}
Add automatic handling of common command failures of Mink elements Commands executed on Mink elements may fail for several reasons. ElementWrapper is introduced to automatically handle some of those situations, like StaleElementReference exceptions and ElementNotVisible exceptions. StaleElementReference exceptions are thrown when the command is executed on an element that is no longer attached to the DOM. When that happens the ElementWrapper finds again the element and executes the command again on the new element. ElementNotVisible exceptions are thrown when the command requires the element to be visible but the element is not. When that happens the ElementWrapper waits for the element to be visible before executing the command again. These changes are totally compatible with the current acceptance tests. They just make the tests more robust, but they do not change their behaviour. In fact, this should minimize some of the sporadic failures in the acceptance tests caused by their concurrent nature with respect to the web browser executing the commands. However, the ElementWrapper is not a silver bullet; it handles the most common situations, but it does not handle every possible scenario. For example, the acceptance tests would still fail sporadically if an element can become staled several times in a row (uncommon) or if it does not become visible before the timeout expires (which could still happen in a loaded system even if the components under test work right, but obviously it is not possible to wait indefinitely for them). Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>
2017-05-05 23:54:20 +03:00
/**
* Returns the description of the element to find.
*
* @return string the description of the element to find.
*/
public function getDescription() {
return $this->elementLocator->getDescription();
}
/**
* Returns the timeout.
*
* @return float the number of seconds (decimals allowed) to wait at most
* for the element to appear.
*/
public function getTimeout() {
return $this->timeout;
}
/**
* Returns the timeout step.
*
* @return float the number of seconds (decimals allowed) to wait before
* trying to find the element again.
*/
public function getTimeoutStep() {
return $this->timeoutStep;
}
/**
* Finds an element using the parameters set in the constructor of this
* ElementFinder.
*
* If the element, or its ancestors, can not be found a
* NoSuchElementException is thrown.
*
* @return \Behat\Mink\Element\Element the element found.
* @throws NoSuchElementException if the element, or its ancestor, can not
* be found.
*/
public function find() {
return self::findInternal($this->session, $this->elementLocator, $this->timeout, $this->timeoutStep);
}
}