function testGetUserIDBy()
 {
     $user_id = $this->factory->user->create(array('user_login' => 'theusername', 'user_email' => '*****@*****.**'));
     $this->assertEquals($user_id, eo_get_user_id_by('id', $user_id));
     $this->assertEquals($user_id, eo_get_user_id_by('slug', 'theusername'));
     $this->assertEquals($user_id, eo_get_user_id_by('email', '*****@*****.**'));
     $this->assertEquals(0, eo_get_user_id_by('slug', 'doesnotexist'));
 }
/**
 * Returns HTML mark-up for the fullCalendar
 *
 * It also (indirectly) triggers the enquing of the necessary scripts and styles. The `$args` array
 * accepts exactly the same arguments as the shortcode, they are
 *
 * * **headerleft** (string) What appears on the left of the calendar header. Default 'title'.
 * * **headercenter** (string) What appears on the left of the calendar header. Default ''.
 * * **headerright** (string) What appears on the left of the calendar header. Default 'prev next today'.
 * * **defaultview** (string) The view the calendar loads on. Default 'month',
 * * **event-category** (string|array) Restrict calendar to specified category(ues) (by slug). Default all categories.
 * * **event-venue** (string|array) Restrict calendar to specified venue(s) (by slug). Default all venues.
 * * **timeformat** (string) Time format for calendar. Default 'G:i'.
 * * **axisformat** (string) Axis time format (for day/week views). WP's time format option.
 * * **key** (bool) Whether to show a category key. Default false.
 * * **tooltip** (bool) Whether to show a tooltips. Default true. Content is filtered by [`eventorganiser_event_tooltip`](http://codex.wp-event-organiser.com/hook-eventorganiser_event_tooltip.html)
 * * **users_events** - (bool) True to show only eents for which the current user is attending
 * * **weekends** (bool) Whether to include weekends in the calendar. Default true.
 * * **mintime** (string) Earliest time to show on week/day views. Default '0',
 * * **maxtime** (string) Latest time to show on week/day views. Default '24',
 * * **alldayslot** (bool) Whether to include an all day slot (week / day views) in the calendar. Default true.
 * * **alldaytext** (string) Text to display in all day slot. Default 'All Day'.
 * * **titleformatmonth** (string) Date format (PHP) for title for month view. Default 'l, M j, Y'
 * * **titleformatweek** (string) Date format (PHP) for title for week view. Default 'M j[ Y]{ '—'[ M] j Y}.
 * * **titleformatday** (string) Date format (PHP) for title for day view. Default 'F Y'
 * * **columnformatmonth** (string) Dateformat for month columns. Default 'D'.
 * * **columnformatweek** (string) Dateformat for month columns. Default 'D n/j'.
 * * **columnformatday** (string) Dateformat for month columns. Default 'l n/j',
 * * **year** The year the calendar should start on (e.g. 2013)
 * * **month** The month the calendar should start on (1=Jan, 12=Dec)
 * * **date** The calendar the date should start on
 *
 * @link http://arshaw.com/fullcalendar/ The fullCalendar (jQuery plug-in)
 * @link http://arshaw.com/fullcalendar/docs/utilities/formatDates/ (Range formats).
 * @link https://github.com/stephenharris/fullcalendar Event Organiser version of fullCalendar
 * @since 1.7
 * @param array $args An array of attributes for the calendar 
 * @return string HTML mark-up.
*/
function eo_get_event_fullcalendar($args = array())
{
    global $wp_locale;
    $defaults = array('headerleft' => 'title', 'headercenter' => '', 'headerright' => 'prev next today', 'defaultview' => 'month', 'event-category' => '', 'event_category' => '', 'event-venue' => '', 'event_venue' => '', 'event-tag' => '', 'author' => false, 'author_name' => false, 'timeformat' => get_option('time_format'), 'axisformat' => get_option('time_format'), 'key' => false, 'tooltip' => true, 'weekends' => true, 'mintime' => '0', 'maxtime' => '24', 'alldayslot' => true, 'alldaytext' => __('All Day', 'eventorganiser'), 'columnformatmonth' => 'D', 'columnformatweek' => 'D n/j', 'columnformatday' => 'l n/j', 'titleformatmonth' => 'F Y', 'titleformatweek' => "M j[ Y]{ '—'[ M] j, Y}", 'titleformatday' => 'l, M j, Y', 'year' => false, 'month' => false, 'date' => false, 'users_events' => false, 'event_occurrence__in' => array(), 'theme' => true, 'isrtl' => $wp_locale->is_rtl());
    $args = shortcode_atts($defaults, $args, 'eo_fullcalendar');
    $key = $args['key'];
    unset($args['key']);
    //Support 'event-category' and 'event-venue'. Backwards compat with 'event_category'/'event_venue'
    $args['event-category'] = empty($args['event_category']) ? $args['event-category'] : $args['event_category'];
    $args['event-venue'] = empty($args['event_venue']) ? $args['event-venue'] : $args['event_venue'];
    //Convert event_category / event_venue to comma-delimitered strings
    $args['event_category'] = is_array($args['event-category']) ? implode(',', $args['event-category']) : $args['event-category'];
    $args['event_venue'] = is_array($args['event-venue']) ? implode(',', $args['event-venue']) : $args['event-venue'];
    $args['event_tag'] = is_array($args['event-tag']) ? implode(',', $args['event-tag']) : $args['event-tag'];
    //Get author ID from author/author_name
    $args['event_organiser'] = $args['author'] ? (int) $args['author'] : eo_get_user_id_by('slug', $args['author_name']);
    //Convert php time format into xDate time format
    $date_attributes = array('timeformat', 'axisformat', 'columnformatday', 'columnformatweek', 'columnformatmonth', 'titleformatmonth', 'titleformatday', 'titleformatweek');
    $args['timeformatphp'] = $args['timeformat'];
    foreach ($date_attributes as $date_attribute) {
        $args[$date_attribute] = str_replace('((', '[', $args[$date_attribute]);
        $args[$date_attribute] = str_replace('))', ']', $args[$date_attribute]);
        $args[$date_attribute . 'php'] = $args[$date_attribute];
        $args[$date_attribute] = eventorganiser_php2xdate($args[$date_attribute]);
    }
    //Month expects 0-11, we ask for 1-12.
    $args['month'] = $args['month'] ? $args['month'] - 1 : false;
    EventOrganiser_Shortcodes::$calendars[] = array_merge($args);
    EventOrganiser_Shortcodes::$add_script = true;
    $id = count(EventOrganiser_Shortcodes::$calendars);
    $html = '<div id="eo_fullcalendar_' . $id . '_loading" style="background:white;position:absolute;z-index:5" >';
    $html .= sprintf('<img src="%1$s" style="vertical-align:middle; padding: 0px 5px 5px 0px;" alt="%2$s" /> %2$s', esc_url(EVENT_ORGANISER_URL . 'css/images/loading-image.gif'), esc_html__('Loading&#8230;', 'eventorganiser'));
    $html .= '</div>';
    $html .= '<div class="eo-fullcalendar eo-fullcalendar-shortcode" id="eo_fullcalendar_' . $id . '"></div>';
    if ($key) {
        $args = array('orderby' => 'name', 'show_count' => 0, 'hide_empty' => 0);
        $html .= eventorganiser_category_key($args, $id);
    }
    return $html;
}