User:Niedzielski/global.js

Note: After publishing, you may have to bypass your browser's cache to see the changes.

Firefox / Safari: Hold Shift while clicking Reload, or press either Ctrl-F5 or Ctrl-R (⌘-R on a Mac)
Google Chrome: Press Ctrl-Shift-R (⌘-Shift-R on a Mac)
Internet Explorer / Edge: Hold Ctrl while clicking Refresh, or press Ctrl-F5
Opera: Press Ctrl-F5.

// https://www.mediawiki.org/wiki/Extension:EventLogging/Guide#QA
var $el = $( '<pre style="background: yellow; margin: 0; padding: 8px; position: fixed; top: 0; width: 100%; z-index: 99"></pre>' );
$el.click( function () { $el.empty().detach(); } );
mw.trackSubscribe( 'eventlogging.error', function ( topic, err ) {
    $el.text( function ( idx, text ) {
        return ( text && text + '\n' ) + err;
    } ).appendTo( 'body' );
} );