PHP Mink/Zombie - handling hanging processes after a fatal exception?

Question

I'm using the PHP script with Mink+Zombie driver (install as on nodejs cannot find module 'zombie' with PHP mink) from here: PHP Mink/Zombie - page visit returns status code 0? ; re-posting for completeness:

<?php
$nodeModPath = "/home/USERNAME/.nvm/versions/node/v4.0.0/lib/node_modules";

# composer autoload:
require_once __DIR__ . '/vendor/autoload.php';

$URL = "https://demo.centreon.com/centreon";
$USERNAME = "admin";
$PASSWORD = "centreon";
$LFID = "useralias";
$PFID = "password";
$BFID = "submitLogin";


$zsrv = new \Behat\Mink\Driver\NodeJS\Server\ZombieServer();
$zsrv->setNodeModulesPath($nodeModPath . "/"); # needs to end with a trailing '/'
$driver = new \Behat\Mink\Driver\ZombieDriver( $zsrv );
$session = new \Behat\Mink\Session($driver);

// start the session
$session->start();
$session->setRequestHeader('User-Agent', 'Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2049.0 Safari/537.36');

$statcode = 0;
while ($statcode != 200) {
  $isleep = rand(2, 7); echo "sleeping $isleep sec...\n";
  sleep($isleep);
  $session->visit($URL);
  // $session->wait(20000, '(0 === jQuery.active)'); # Uncaught exception 'RuntimeException' with message 'Could not establish connection: Connection refused (111)'
  $session->wait(20000, '(browser.statusCode > 0)'); ### THIS makes things work?!
  $statcode = $session->getStatusCode();
  echo "  current URL: " . $session->getCurrentUrl() ."\n";
  echo "  status code: " . $statcode ."\n";
}

$page = $session->getPage();
$el_login = $page->findField($LFID);
$el_password = $page->findField($PFID);
$el_button = $page->find('xpath', '//*[@name="'.$BFID.'"]');//findById($BFID);//findField($BFID);

$el_login->setValue($USERNAME);
$el_password->setValue($PASSWORD);

echo "  pressing/clicking login button\n";
$el_button->click();

echo "Page URL after click: ". $session->getCurrentUrl() . "\n";
$page = $session->getPage();
?>

The problem is, when the script runs, and does a login click, some JavaScript libraries that the page uses cannot be detected by Mink, and an exception is raised:

$ php test_php_mink.php 
sleeping 4 sec...
  current URL: https://demo.centreon.com/centreon/
  status code: 200
  pressing/clicking login button
PHP Fatal error:  Uncaught exception 'Behat\Mink\Exception\DriverException' with message 'Error while processing event 'click': "ReferenceError: Effect is not defined\n    at https://demo.centreon.com/centreon/include/common/javascript/modalbox.js:517:1\n    at Object.exports.runInContext (vm.js:44:17)\n    at window._evaluate (/home/USERNAME/.nvm/versions/node/v4.0.0/lib/node_modules/zombie/lib/document.js:253:75)\n    at Object.DOM.languageProcessors.javascript (/home/USERNAME/.nvm/versions/node/v4.0.0/lib/node_modules/zombie/lib/dom/scripts.js:26:12)\n    at define.proto._eval (/home/USERNAME/.nvm/versions/node/v4.0.0/lib/node_modules/zombie/node_modules/jsdom/lib/jsdom/level2/html.js:1477:47)\n    at /home/USERNAME/.nvm/versions/node/v4.0.0/lib/node_modules/zombie/node_modules/jsdom/lib/jsdom/browser/resource-loader.js:32:22\n    at Object.item.check (/home/USERNAME/.nvm/versions/node/v4.0.0/lib/node_modules/zombie/node_modules/jsdom/lib/jsdom/level2/html.js:188:11)\n    at Object.item.check (/home in /path/to/test_php_mink/vendor/behat/mink-zombie-driver/src/ZombieDriver.php on line 880

The exception is ReferenceError: Effect is not defined, and it is due to the page using this javascript:

<script type="text/javascript" src="./include/common/javascript/scriptaculous/scriptaculous.js?load=effects,dragdrop"></script>
...
    new Effect.toggle('header', 'appear', { afterFinish: function() {

However, the even bigger problem is that after this crash happens, then when I run the script for a second time, it crashes almost immediately, this time with Error: listen EADDRINUSE 127.0.0.1:8124:

$ php test_php_mink.php 
PHP Fatal error:  Uncaught exception 'RuntimeException' with message 'Server process has been terminated: (1) [events.js:141
      throw er; // Unhandled 'error' event
      ^

Error: listen EADDRINUSE 127.0.0.1:8124
    at Object.exports._errnoException (util.js:837:11)
    at exports._exceptionWithHostPort (util.js:860:20)
    at Server._listen2 (net.js:1231:14)
    at listen (net.js:1267:10)
    at net.js:1376:9
    at doNTCallback3 (node.js:440:9)
    at process._tickCallback (node.js:346:17)
    at Function.Module.runMain (module.js:473:11)
    at startup (node.js:117:18)
    at node.js:951:3
]' in /path/to/test_php_mink/vendor/behat/mink-zombie-driver/src/NodeJS/Server.php:413
Stack trace:
#0 /path/to/test_php_mink/vendor/behat/mink-zombie-driver/src/NodeJS/Server.php(306): Behat\Mink\Driver\NodeJS\Server->checkAvailability()
#1 /path/to/test_php_mink/vendor/behat/mink-zombie-driver/src/ZombieDriver. in /path/to/test_php_mink/vendor/behat/mink-zombie-driver/src/NodeJS/Server.php on line 413

It seems that after the first crash, there are still mink processes hanging around - and indeed, there are:

$ pgrep -fl mink
7659 sh
7660 node

$ ps axf | grep mink
 7687 pts/0    S+     0:00  |       \_ grep --color=tty mink
 7659 pts/0    S      0:00 sh -c 'node' '/path/to/test_php_mink/vendor/behat/mink-zombie-driver/bin/mink-zombie-server.js'
 7660 pts/0    Sl     0:03  \_ node /path/to/test_php_mink/vendor/behat/mink-zombie-driver/bin/mink-zombie-server.js

At this point, if I kill these processes - say, with pkill -f mink - then they disappear from the process tree, and then I can run the script again, with the same results as the first call in the OP (and then I have to kill processes again, etc).

What would be the best/recommended way to handle this, so I don't have to manually kill processes, each time the script reaches a fatal exception? Is there something in the Mink library that would allow for this?

Faretheewell

Note, I tested this with zombie v4.2.1 with nodejs versions iojs-v3.3.1, 4.0.0, 4.4.5, 6.2.0 - and they all fail with this script in the exactly same way. – Faretheewell

Answer 1

First thing to do in order to avoid fatal exceptions is to implement/use methods with proper error handling. You can create a method to check if the element is not null and if it is to throw a custom exception.

For example in your case findField method will return null if the element is not found, in this case setValue will e used on a non-object resulting in a fatal error.

Ragi

Thanks for that, @Ragi - I'm still not clear on exactly how to implement a method with proper error handling, but I'll look it up... Cheers! – Faretheewell

OK, I did a bit more testing, and I did echo "Check: el_l: " . gettype($el_login) . " el_p: " . gettype($el_password) . " el_b " . gettype($el_button) . "\n"; after the findField commands, and none of the objects is null: Check: el_l: object el_p: object el_b object. So, the exception does not happen because setValue() or click() is called on a non-object - as stated in the OP, the exception happens somewhere inside the click method, due to an exter JS class not being found. So, the question is still open... – Faretheewell

How do you set $BFID? Do you need to click or you have a slider or something like that? If this is a special case and click action is working in other cases have you tried to use executeScript for this case? – Ragi

It is possible that the element would not receive the click? Can you post the html code with element you are trying to click?, it would be helpful. – Ragi

$BFID is set at top of the OP script: $BFID = "submitLogin"; - it's just a string. Btw, the entire PHP file is self-contained, if you have installed mink/zombie - you can just copy paste into a file and run it with php fromk php-cli. And as the script says, the page loaded is $URL = "https://demo.centreon.com/centreon";. – Faretheewell

Sorry i missed that. I see the button is clicked if execute the following javascript in the browser: document.querySelector("[name*='submitLogin']").click(); – Ragi

Answer 2

An example of exception handling is:

public function fillWith($locator, $text){
        $element = $this->getSession()->getPage()->find("xpath", $locator);

        if($element === null){
            throw new Exception("Element $locator not found");
        }else{
            $element->setValue($text);
        }
    }

Ragi

Thanks @Ragi - you should have edited your old answer to put this information in; but it still doesn't change the fact that non-object exception handling is not the problem here... – Faretheewell