Acceptance testing/Migrating from Behat 2.5 to 3.x in Moodle

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Migrating from Behat 2.5 to 3.x in Moodle

Behat 3 brings a lot of extensibility and modularity for the price of backward compatibility break. This guide describes several issues you might face when updating your plugin acceptance test to the latest Moodle 3.1@dev version.

Config variables

behat_profiles

Most of the configuration for a behat profile can be set in $CFG->behat_profiles. This configuration parameter is available since Moodle 2.9.6, Moodle 3.0.4, and Moodle 3.1.

Here is a quick example that changes the browser from the default firefox to chrome on Linux systems (note that you have to have the Chrome web driver installed in your system path)

$CFG->behat_profiles = [
    'default' => [
        'browser' => 'chrome',
        'extensions' => [
            'Behat\MinkExtension' => [
                'selenium2' => [
                    'browser' => 'chrome',
                ]
            ]
        ]
    ]
];

The settings available here include the browser name, tags, webdriver configuration, and capabilities:

$CFG->behat_profiles = array(
   'phantomjs' => array(
       'browser' => 'phantomjs',
       'tags' => '~@_file_upload&&~@_alert&&~@_bug_phantomjs',
       'wd_host' => 'http://127.0.0.1:4443/wd/hub',
       'capabilities' => array(
           'platform' => 'Linux',
           'version' => 2.1
       )
   )
);

In certain situations more advanced configuration is required - for example specification of a proxy server to use. This configuration must be specified in $CFG->behat_config. Note: If a value is specified in both behat_config, and behat_profiles, the version in behat_profiles will take precedence

behat_config

Structure of $CFG->behat_config has been modified and you should now use

$CFG->behat_config = array(
   'phantomjs' => array(
      'suites' => array (
          'default' => array(
              'filters' => array(
                 'tags' => '~@_file_upload&&~@_alert&&~@_bug_phantomjs'
              ),
           ),
       ),
       'extensions' => array(
            'Behat\MinkExtension' => array(
                  'selenium2' => array(
                      'browser' => 'phantomjs',
                      'wd_host' => "http://127.0.0.1:4443/wd/hub"
                  )
              )
          )
     ),
);

Formats and outputs

html and failed outputs are not maintained by behat. We are planning to include BehatHTMLFormatter plugin maintained by Neal Vanmeert and write our custom failed formatter. Changes required to use formatter and outputs are

Single option per formatter

Multiple formats should be sent as separate options with respective output option

     vendor/bin/behat --config /PATH/FOR/BEHAT_DATAROOT/behatrun/behat/behat.yml --format=moodle_progress --out=/PATH/TO/SAVE/progress.txt --format=moodle_screenshot --out=/PATH/TO/SAVE/SCREENSHOT_DIR

Terminal output is std

For output to terminal use std

      vendor/bin/behat --config /PATH/FOR/BEHAT_DATAROOT/behatrun/behat/behat.yml --format=moodle_progress --out=std

Formatter can be used once

One formatter is supported for each run. Means if you want to output progress to file and terminal then it is not supported. You need to use 2 different formatter like moodle_progress and progress

      vendor/bin/behat --config /PATH/FOR/BEHAT_DATAROOT/behatrun/behat/behat.yml --format=moodle_progress --out=std --format=progress --out=/PATH/TO/SAVE/progress.txt

Custom formatters

Following custom formatter are supported

  1. moodle_progress: Prints Moodle branch information and dots for each step.
  2. moodle_list: List all scenarios.
  3. moodle_stepcount: List all features with total steps in each feature file. Used for parallel run.
  4. moodle_screenshot: Take screenshot and core dump of each step. With following options you can dump either or both.
    1. --format-settings '{"formats": "image"}'**: will dump image only
    2. --format-settings '{"formats": "html"}'**: will dump html only.
    3. --format-settings '{"formats": "html,image"}'**: will dump both.
    4. --format-settings '{"formats": "html", "dir_permissions": "0777"}'**

Running test

Rerun option doesn't accept filepath

Rerun should be used without the filepath, as the failed scenarios are now cached by behat and rerun.

vendor/bin/behat --config /PATH/FOR/BEHAT_DATAROOT/behatrun/behat/behat.yml
exitcode=${PIPESTATUS[0]}
if [ "${exitcode}" -ne 0 ]; then
  vendor/bin/behat --config /PATH/FOR/BEHAT_DATAROOT/behatrun/behat/behat.yml --rerun
fi

Rerun for parallel run

Rerun file is cached with a unique key which is generated using input arguments. As in parallel run they all are same, the rerun file gets overwritten by the last failing run. To avoid this:

  1. Add 3 profiles in your config for each run say: firefox_1, firefox_2, firefox_3 for 3 parallel runs
  2. use --profile="firefox_{runprocess} --replace="{runprocess}" options for run.php
NOTE: Behat issue have been waiting for this to be resolved by including basepath to generate the unique key.

Exit code for parallel run is bitmasked

Exit code is now bitmasked contains pass/fail information of each run in every bit (starting from 0th bit). Example: If you have 3 parallel runs, out of which Run 1 and 3 failed. Then exit code will be 5 (0b0101). This will help to identify which runs need to be executed again for avoiding random failures.

If you want to use specific path where failed scenarios should be saved for rerun then you can set the following config:
$CFG->behat_config = array(
    'default' => array(
        'testers' => array(
            'rerun_cache' => '/home/rajesh/Desktop/rerun'
        ),
    ),
);

Failed output

Failed output is different: Failed output display step and line in file where it failed and not the scenario line number.

Changes required in context file

Custom chained steps support

Chained steps are not supported by Behat 3. We have added support for custom chained step via moodle-behat-extension, but planning to depreciate this in future. To make your context backward compatible you should replace chained steps with the api calls in your context. Example the following chained steps

$steps = array(
            new Given('I click on "' . get_string('login') . '" "link" in the ".logininfo" "css_element"'),		
            new Given('I set the field "' . get_string('username') . '" to "' . $this->escape($username) . '"'),		
            new Given('I set the field "' . get_string('password') . '" to "'. $this->escape($username) . '"'),		
            new Given('I press "' . get_string('login') . '"')		
        );

can be replaced with

// Click on login link.
$this->execute('behat_general::i_click_on_in_the',
    array(get_string('login'), 'link', '.logininfo', 'css_element'));
// Enter username and password.
$this->execute('behat_forms::i_set_the_field_to', array('Username', $this->escape($username)));
$this->execute('behat_forms::i_set_the_field_to', array('Password', $this->escape($username)));
// Press log in button.
$this->execute('behat_forms::press_button', get_string('login'));

TableNode

Table Node class has changed and requires following modifications:

  1. TableNode constructor has changed, and it requires least empty array().
  2. addRow() api is deprecated, if you are modifying rows then save that in an array and create a new TableNode()
$rows = $options->getRows();
$newrows = array();
foreach ($rows as $k => $data) {
    $newrows[$k] = strtr($data, "äåö", "aao");
}
$modifiedtable = = new TableNode($newrows);

Named selectors are depreciated

Named selector is deprecated, you should either use named_exact or named_partial

$this->find('named_partial', array('link', get_string('hide')), $nohideexception, $activitynode);