moodle/lib/behat/behat_base.php
David Monllao c1faf86bd1 MDL-42625 behat: Make behat pacient
* When looking for texts inside the page or inside
  other containers we should wait until the elements
  are visible.
* Same when expanding tree nodes.
* Normalizing loops to spin() function using
  behat_base::TIMEOUT and behat_base::EXTENDED_TIMEOUT,
  leaving TIMEOUT for DOM load processes and
  EXTENDED_TIMEOUT for long processes that involves JS
  too.
* Add page load waits between actions that involves
  reloading the page.
2013-12-09 11:08:42 +08:00

624 lines
24 KiB
PHP

<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Base class of all steps definitions.
*
* This script is only called from Behat as part of it's integration
* in Moodle.
*
* @package core
* @category test
* @copyright 2012 David Monllaó
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
// NOTE: no MOODLE_INTERNAL test here, this file may be required by behat before including /config.php.
use Behat\Mink\Exception\ExpectationException as ExpectationException,
Behat\Mink\Exception\ElementNotFoundException as ElementNotFoundException,
Behat\Mink\Element\NodeElement as NodeElement;
/**
* Steps definitions base class.
*
* To extend by the steps definitions of the different Moodle components.
*
* It can not contain steps definitions to avoid duplicates, only utility
* methods shared between steps.
*
* @method NodeElement find_field(string $locator) Finds a form element
* @method NodeElement find_button(string $locator) Finds a form input submit element or a button
* @method NodeElement find_link(string $locator) Finds a link on a page
* @method NodeElement find_file(string $locator) Finds a forum input file element
*
* @package core
* @category test
* @copyright 2012 David Monllaó
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class behat_base extends Behat\MinkExtension\Context\RawMinkContext {
/**
* The timeout for each Behat step (load page, wait for an element to load...).
*/
const TIMEOUT = 3;
/**
* And extended timeout for specific cases.
*/
const EXTENDED_TIMEOUT = 10;
/**
* The JS code to check that the page is ready.
*/
const PAGE_READY_JS = '(M && M.util && M.util.pending_js && !Boolean(M.util.pending_js.length)) && (document.readyState === "complete")';
/**
* Locates url, based on provided path.
* Override to provide custom routing mechanism.
*
* @see Behat\MinkExtension\Context\MinkContext
* @param string $path
* @return string
*/
protected function locate_path($path) {
$starturl = rtrim($this->getMinkParameter('base_url'), '/') . '/';
return 0 !== strpos($path, 'http') ? $starturl . ltrim($path, '/') : $path;
}
/**
* Returns the first matching element.
*
* @link http://mink.behat.org/#traverse-the-page-selectors
* @param string $selector The selector type (css, xpath, named...)
* @param mixed $locator It depends on the $selector, can be the xpath, a name, a css locator...
* @param Exception $exception Otherwise we throw exception with generic info
* @param NodeElement $node Spins around certain DOM node instead of the whole page
* @return NodeElement
*/
protected function find($selector, $locator, $exception = false, $node = false) {
// Returns the first match.
$items = $this->find_all($selector, $locator, $exception, $node);
return count($items) ? reset($items) : null;
}
/**
* Returns all matching elements.
*
* Adapter to Behat\Mink\Element\Element::findAll() using the spin() method.
*
* @link http://mink.behat.org/#traverse-the-page-selectors
* @param string $selector The selector type (css, xpath, named...)
* @param mixed $locator It depends on the $selector, can be the xpath, a name, a css locator...
* @param Exception $exception Otherwise we throw expcetion with generic info
* @param NodeElement $node Spins around certain DOM node instead of the whole page
* @return array NodeElements list
*/
protected function find_all($selector, $locator, $exception = false, $node = false) {
// Generic info.
if (!$exception) {
// With named selectors we can be more specific.
if ($selector == 'named') {
$exceptiontype = $locator[0];
$exceptionlocator = $locator[1];
// If we are in a @javascript session all contents would be displayed as HTML characters.
if ($this->running_javascript()) {
$locator[1] = html_entity_decode($locator[1], ENT_NOQUOTES);
}
} else {
$exceptiontype = $selector;
$exceptionlocator = $locator;
}
$exception = new ElementNotFoundException($this->getSession(), $exceptiontype, null, $exceptionlocator);
}
$params = array('selector' => $selector, 'locator' => $locator);
// Pushing $node if required.
if ($node) {
$params['node'] = $node;
}
// Waits for the node to appear if it exists, otherwise will timeout and throw the provided exception.
return $this->spin(
function($context, $args) {
// If no DOM node provided look in all the page.
if (empty($args['node'])) {
return $context->getSession()->getPage()->findAll($args['selector'], $args['locator']);
}
// For nodes contained in other nodes we can not use the basic named selectors
// as they include unions and they would look for matches in the DOM root.
$elementxpath = $context->getSession()->getSelectorsHandler()->selectorToXpath($args['selector'], $args['locator']);
// Split the xpath in unions and prefix them with the container xpath.
$unions = explode('|', $elementxpath);
foreach ($unions as $key => $union) {
$union = trim($union);
// We are in the container node.
if (strpos($union, '.') === 0) {
$union = substr($union, 1);
} else if (strpos($union, '/') !== 0) {
// Adding the path separator in case it is not there.
$union = '/' . $union;
}
$unions[$key] = $args['node']->getXpath() . $union;
}
// We can not use usual Element::find() as it prefixes with DOM root.
return $context->getSession()->getDriver()->find(implode('|', $unions));
},
$params,
self::TIMEOUT,
$exception
);
}
/**
* Finds DOM nodes in the page using named selectors.
*
* The point of using this method instead of Mink ones is the spin
* method of behat_base::find() that looks for the element until it
* is available or it timeouts, this avoids the false failures received
* when selenium tries to execute commands on elements that are not
* ready to be used.
*
* All steps that requires elements to be available before interact with
* them should use one of the find* methods.
*
* The methods calls requires a {'find_' . $elementtype}($locator)
* format, like find_link($locator), find_select($locator),
* find_button($locator)...
*
* @link http://mink.behat.org/#named-selectors
* @throws coding_exception
* @param string $name The name of the called method
* @param mixed $arguments
* @return NodeElement
*/
public function __call($name, $arguments) {
if (substr($name, 0, 5) !== 'find_') {
throw new coding_exception('The "' . $name . '" method does not exist');
}
// Only the named selector identifier.
$cleanname = substr($name, 5);
// All named selectors shares the interface.
if (count($arguments) !== 1) {
throw new coding_exception('The "' . $cleanname . '" named selector needs the locator as it\'s single argument');
}
// Redirecting execution to the find method with the specified selector.
// It will detect if it's pointing to an unexisting named selector.
return $this->find('named',
array(
$cleanname,
$this->getSession()->getSelectorsHandler()->xpathLiteral($arguments[0])
)
);
}
/**
* Escapes the double quote character.
*
* Double quote is the argument delimiter, it can be escaped
* with a backslash, but we auto-remove this backslashes
* before the step execution, this method is useful when using
* arguments as arguments for other steps.
*
* @param string $string
* @return string
*/
public function escape($string) {
return str_replace('"', '\"', $string);
}
/**
* Executes the passed closure until returns true or time outs.
*
* In most cases the document.readyState === 'complete' will be enough, but sometimes JS
* requires more time to be completely loaded or an element to be visible or whatever is required to
* perform some action on an element; this method receives a closure which should contain the
* required statements to ensure the step definition actions and assertions have all their needs
* satisfied and executes it until they are satisfied or it timeouts. Redirects the return of the
* closure to the caller.
*
* The closures requirements to work well with this spin method are:
* - Must return false, null or '' if something goes wrong
* - Must return something != false if finishes as expected, this will be the (mixed) value
* returned by spin()
*
* The arguments of the closure are mixed, use $args depending on your needs.
*
* You can provide an exception to give more accurate feedback to tests writers, otherwise the
* closure exception will be used, but you must provide an exception if the closure does not throws
* an exception.
*
* @throws Exception If it timeouts without receiving something != false from the closure
* @param Function|array|string $lambda The function to execute or an array passed to call_user_func (maps to a class method)
* @param mixed $args Arguments to pass to the closure
* @param int $timeout Timeout in seconds
* @param Exception $exception The exception to throw in case it time outs.
* @param bool $microsleep If set to true it'll sleep micro seconds rather than seconds.
* @return mixed The value returned by the closure
*/
protected function spin($lambda, $args = false, $timeout = false, $exception = false, $microsleep = false) {
// Using default timeout which is pretty high.
if (!$timeout) {
$timeout = self::TIMEOUT;
}
if ($microsleep) {
// Will sleep 1/10th of a second by default for self::TIMEOUT seconds.
$loops = $timeout * 10;
} else {
// Will sleep for self::TIMEOUT seconds.
$loops = $timeout;
}
for ($i = 0; $i < $loops; $i++) {
// We catch the exception thrown by the step definition to execute it again.
try {
// We don't check with !== because most of the time closures will return
// direct Behat methods returns and we are not sure it will be always (bool)false
// if it just runs the behat method without returning anything $return == null.
if ($return = call_user_func($lambda, $this, $args)) {
return $return;
}
} catch (Exception $e) {
// We would use the first closure exception if no exception has been provided.
if (!$exception) {
$exception = $e;
}
// We wait until no exception is thrown or timeout expires.
continue;
}
if ($microsleep) {
usleep(100000);
} else {
sleep(1);
}
}
// Using coding_exception as is a development issue if no exception has been provided.
if (!$exception) {
$exception = new coding_exception('spin method requires an exception if the callback does not throw an exception');
}
// Throwing exception to the user.
throw $exception;
}
/**
* Gets a NodeElement based on the locator and selector type received as argument from steps definitions.
*
* Use behat_base::get_text_selector_node() for text-based selectors.
*
* @throws ElementNotFoundException Thrown by behat_base::find
* @param string $selectortype
* @param string $element
* @return NodeElement
*/
protected function get_selected_node($selectortype, $element) {
// Getting Mink selector and locator.
list($selector, $locator) = $this->transform_selector($selectortype, $element);
// Returns the NodeElement.
return $this->find($selector, $locator);
}
/**
* Gets a NodeElement based on the locator and selector type received as argument from steps definitions.
*
* @throws ElementNotFoundException Thrown by behat_base::find
* @param string $selectortype
* @param string $element
* @return NodeElement
*/
protected function get_text_selector_node($selectortype, $element) {
// Getting Mink selector and locator.
list($selector, $locator) = $this->transform_text_selector($selectortype, $element);
// Returns the NodeElement.
return $this->find($selector, $locator);
}
/**
* Gets the requested element inside the specified container.
*
* @throws ElementNotFoundException Thrown by behat_base::find
* @param mixed $selectortype The element selector type.
* @param mixed $element The element locator.
* @param mixed $containerselectortype The container selector type.
* @param mixed $containerelement The container locator.
* @return NodeElement
*/
protected function get_node_in_container($selectortype, $element, $containerselectortype, $containerelement) {
// Gets the container, it will always be text based.
$containernode = $this->get_text_selector_node($containerselectortype, $containerelement);
list($selector, $locator) = $this->transform_selector($selectortype, $element);
// Specific exception giving info about where can't we find the element.
$locatorexceptionmsg = $element . '" in the "' . $containerelement. '" "' . $containerselectortype. '"';
$exception = new ElementNotFoundException($this->getSession(), $selectortype, null, $locatorexceptionmsg);
// Looks for the requested node inside the container node.
return $this->find($selector, $locator, $exception, $containernode);
}
/**
* Transforms from step definition's argument style to Mink format.
*
* Mink has 3 different selectors css, xpath and named, where named
* selectors includes link, button, field... to simplify and group multiple
* steps in one we use the same interface, considering all link, buttons...
* at the same level as css selectors and xpath; this method makes the
* conversion from the arguments received by the steps to the selectors and locators
* required to interact with Mink.
*
* @throws ExpectationException
* @param string $selectortype It can be css, xpath or any of the named selectors.
* @param string $element The locator (or string) we are looking for.
* @return array Contains the selector and the locator expected by Mink.
*/
protected function transform_selector($selectortype, $element) {
// Here we don't know if an allowed text selector is being used.
$selectors = behat_selectors::get_allowed_selectors();
if (!isset($selectors[$selectortype])) {
throw new ExpectationException('The "' . $selectortype . '" selector type does not exist', $this->getSession());
}
return behat_selectors::get_behat_selector($selectortype, $element, $this->getSession());
}
/**
* Transforms from step definition's argument style to Mink format.
*
* Delegates all the process to behat_base::transform_selector() checking
* the provided $selectortype.
*
* @throws ExpectationException
* @param string $selectortype It can be css, xpath or any of the named selectors.
* @param string $element The locator (or string) we are looking for.
* @return array Contains the selector and the locator expected by Mink.
*/
protected function transform_text_selector($selectortype, $element) {
$selectors = behat_selectors::get_allowed_text_selectors();
if (empty($selectors[$selectortype])) {
throw new ExpectationException('The "' . $selectortype . '" selector can not be used to select text nodes', $this->getSession());
}
return $this->transform_selector($selectortype, $element);
}
/**
* Returns whether the scenario is running in a browser that can run Javascript or not.
*
* @return boolean
*/
protected function running_javascript() {
return get_class($this->getSession()->getDriver()) !== 'Behat\Mink\Driver\GoutteDriver';
}
/**
* Spins around an element until it exists
*
* @throws ExpectationException
* @param string $element
* @param string $selectortype
* @return void
*/
protected function ensure_element_exists($element, $selectortype) {
// Getting the behat selector & locator.
list($selector, $locator) = $this->transform_selector($selectortype, $element);
// Exception if it timesout and the element is still there.
$msg = 'The "' . $element . '" element does not exist and should exist';
$exception = new ExpectationException($msg, $this->getSession());
// It will stop spinning once the find() method returns true.
$this->spin(
function($context, $args) {
// We don't use behat_base::find as it is already spinning.
if ($context->getSession()->getPage()->find($args['selector'], $args['locator'])) {
return true;
}
return false;
},
array('selector' => $selector, 'locator' => $locator),
self::EXTENDED_TIMEOUT,
$exception,
true
);
}
/**
* Spins until the element does not exist
*
* @throws ExpectationException
* @param string $element
* @param string $selectortype
* @return void
*/
protected function ensure_element_does_not_exist($element, $selectortype) {
// Getting the behat selector & locator.
list($selector, $locator) = $this->transform_selector($selectortype, $element);
// Exception if it timesout and the element is still there.
$msg = 'The "' . $element . '" element exists and should not exist';
$exception = new ExpectationException($msg, $this->getSession());
// It will stop spinning once the find() method returns false.
$this->spin(
function($context, $args) {
// We don't use behat_base::find() as we are already spinning.
if (!$context->getSession()->getPage()->find($args['selector'], $args['locator'])) {
return true;
}
return false;
},
array('selector' => $selector, 'locator' => $locator),
self::EXTENDED_TIMEOUT,
$exception,
true
);
}
/**
* Ensures that the provided node is visible and we can interact with it.
*
* @throws ExpectationException
* @param NodeElement $node
* @return void Throws an exception if it times out without the element being visible
*/
protected function ensure_node_is_visible($node) {
if (!$this->running_javascript()) {
return;
}
// Exception if it timesout and the element is still there.
$msg = 'The "' . $node->getXPath() . '" xpath node is not visible and it should be visible';
$exception = new ExpectationException($msg, $this->getSession());
// It will stop spinning once the isVisible() method returns true.
$this->spin(
function($context, $args) {
if ($args->isVisible()) {
return true;
}
return false;
},
$node,
self::EXTENDED_TIMEOUT,
$exception,
true
);
}
/**
* Ensures that the provided element is visible and we can interact with it.
*
* Returns the node in case other actions are interested in using it.
*
* @throws ExpectationException
* @param string $element
* @param string $selectortype
* @return NodeElement Throws an exception if it times out without being visible
*/
protected function ensure_element_is_visible($element, $selectortype) {
if (!$this->running_javascript()) {
return;
}
$node = $this->get_selected_node($selectortype, $element);
$this->ensure_node_is_visible($node);
return $node;
}
/**
* Ensures that all the page's editors are loaded.
*
* This method is expensive as it waits for .mceEditor CSS
* so use with caution and only where there will be editors.
*
* @throws ElementNotFoundException
* @throws ExpectationException
* @return void
*/
protected function ensure_editors_are_loaded() {
if (!$this->running_javascript()) {
return;
}
// If there are no editors we don't need to wait.
try {
$this->find('css', '.mceEditor');
} catch (ElementNotFoundException $e) {
return;
}
// Exception if it timesout and the element is not appearing.
$msg = 'The editors are not completely loaded';
$exception = new ExpectationException($msg, $this->getSession());
// Here we know that there are .mceEditor editors in the page and we will
// probably need to interact with them, if we use tinyMCE JS var before
// it exists it will throw an exception and we want to catch it until all
// the page's editors are ready to interact with them.
$this->spin(
function($context) {
// It may return 0 if tinyMCE is loaded but not the instances, so we just loop again.
$neditors = $context->getSession()->evaluateScript('return tinyMCE.editors.length;');
if ($neditors == 0) {
return false;
}
// It may be there but not ready.
$iframeready = $context->getSession()->evaluateScript('
var readyeditors = new Array;
for (editorid in tinyMCE.editors) {
if (tinyMCE.editors[editorid].getDoc().readyState === "complete") {
readyeditors[editorid] = editorid;
}
}
if (tinyMCE.editors.length === readyeditors.length) {
return "complete";
}
return "";
');
// Now we know that the editors are there.
if ($iframeready) {
return true;
}
// Loop again if it is not ready.
return false;
},
false,
self::EXTENDED_TIMEOUT,
$exception,
true
);
}
}