text: 'use strict';
  
  var util,
  	config = require( './config.json' );
  
  require( './jquery.accessKeyLabel.js' );
  
  /**
   * Encode the string like PHP's rawurlencode
   *
   * @ignore
   * @param {string} str String to be encoded.
   * @return {string} Encoded string
   */
  function rawurlencode( str ) {
  	return encodeURIComponent( String( str ) )
  		.replace( /!/g, '%21' ).replace( /'/g, '%27' ).replace( /\(/g, '%28' )
  		.replace( /\)/g, '%29' ).replace( /\*/g, '%2A' ).replace( /~/g, '%7E' );
  }
  
  /**
   * Private helper function used by util.escapeId*()
   *
   * @ignore
   * @param {string} str String to be encoded
   * @param {string} mode Encoding mode, see documentation for $wgFragmentMode
   *     in DefaultSettings.php
   * @return {string} Encoded string
   */
  function escapeIdInternal( str, mode ) {
  	str = String( str );
  
  	switch ( mode ) {
  		case 'html5':
  			return str.replace( / /g, '_' );
  		case 'legacy':
  			return rawurlencode( str.replace( / /g, '_' ) )
  				.replace( /%3A/g, ':' )
  				.replace( /%/g, '.' );
  		default:
  			throw new Error( 'Unrecognized ID escaping mode ' + mode );
  	}
  }
  
  /**
   * Utility library
   *
   * @class mw.util
   * @singleton
   */
  util = {
  
  	/**
  	 * Encode the string like PHP's rawurlencode
  	 *
  	 * @param {string} str String to be encoded.
  	 * @return {string} Encoded string
  	 */
  	rawurlencode: rawurlencode,
  
  	/**
  	 * Encode a string as CSS id, for use as HTML id attribute value.
  	 *
  	 * Analog to `Sanitizer::escapeIdForAttribute()` in PHP.
  	 *
  	 * @since 1.30
  	 * @param {string} str String to encode
  	 * @return {string} Encoded string
  	 */
  	escapeIdForAttribute: function ( str ) {
  		return escapeIdInternal( str, config.FragmentMode[ 0 ] );
  	},
  
  	/**
  	 * Encode a string as URL fragment, for use as HTML anchor link.
  	 *
  	 * Analog to `Sanitizer::escapeIdForLink()` in PHP.
  	 *
  	 * @since 1.30
  	 * @param {string} str String to encode
  	 * @return {string} Encoded string
  	 */
  	escapeIdForLink: function ( str ) {
  		return escapeIdInternal( str, config.FragmentMode[ 0 ] );
  	},
  
  	/**
  	 * Return a wrapper function that is debounced for the given duration.
  	 *
  	 * When it is first called, a timeout is scheduled. If before the timer
  	 * is reached the wrapper is called again, it gets rescheduled for the
  	 * same duration from now until it stops being called. The original function
  	 * is called from the "tail" of such chain, with the last set of arguments.
  	 *
  	 * @since 1.34
  	 * @param {number} delay Time in milliseconds
  	 * @param {Function} callback
  	 * @return {Function}
  	 */
  	debounce: function ( delay, callback ) {
  		var timeout;
  		return function () {
  			clearTimeout( timeout );
  			timeout = setTimeout( Function.prototype.apply.bind( callback, this, arguments ), delay );
  		};
  	},
  
  	/**
  	 * Encode page titles for use in a URL
  	 *
  	 * We want / and : to be included as literal characters in our title URLs
  	 * as they otherwise fatally break the title.
  	 *
  	 * The others are decoded because we can, it's prettier and matches behaviour
  	 * of `wfUrlencode` in PHP.
  	 *
  	 * @param {string} str String to be encoded.
  	 * @return {string} Encoded string
  	 */
  	wikiUrlencode: function ( str ) {
  		return util.rawurlencode( str )
  			.replace( /%20/g, '_' )
  			// wfUrlencode replacements
  			.replace( /%3B/g, ';' )
  			.replace( /%40/g, '@' )
  			.replace( /%24/g, '$' )
  			.replace( /%21/g, '!' )
  			.replace( /%2A/g, '*' )
  			.replace( /%28/g, '(' )
  			.replace( /%29/g, ')' )
  			.replace( /%2C/g, ',' )
  			.replace( /%2F/g, '/' )
  			.replace( /%7E/g, '~' )
  			.replace( /%3A/g, ':' );
  	},
  
  	/**
  	 * Get the link to a page name (relative to `wgServer`),
  	 *
  	 * @param {string|null} [pageName=wgPageName] Page name
  	 * @param {Object} [params] A mapping of query parameter names to values,
  	 *  e.g. `{ action: 'edit' }`
  	 * @return {string} Url of the page with name of `pageName`
  	 */
  	getUrl: function ( pageName, params ) {
  		var fragmentIdx, url, query, fragment,
  			title = typeof pageName === 'string' ? pageName : mw.config.get( 'wgPageName' );
  
  		// Find any fragment
  		fragmentIdx = title.indexOf( '#' );
  		if ( fragmentIdx !== -1 ) {
  			fragment = title.slice( fragmentIdx + 1 );
  			// Exclude the fragment from the page name
  			title = title.slice( 0, fragmentIdx );
  		}
  
  		// Produce query string
  		if ( params ) {
  			query = $.param( params );
  		}
  		if ( query ) {
  			url = title ?
  				util.wikiScript() + '?title=' + util.wikiUrlencode( title ) + '&' + query :
  				util.wikiScript() + '?' + query;
  		} else {
  			url = mw.config.get( 'wgArticlePath' )
  				.replace( '$1', util.wikiUrlencode( title ).replace( /\$/g, '$$$$' ) );
  		}
  
  		// Append the encoded fragment
  		if ( fragment && fragment.length ) {
  			url += '#' + util.escapeIdForLink( fragment );
  		}
  
  		return url;
  	},
  
  	/**
  	 * Get URL to a MediaWiki entry point.
  	 *
  	 * @since 1.18
  	 * @param {string} [str="index"] Name of MW entry point (e.g. 'index' or 'api')
  	 * @return {string} URL to the script file (e.g. '/w/api.php' )
  	 */
  	wikiScript: function ( str ) {
  		if ( !str || str === 'index' ) {
  			return mw.config.get( 'wgScript' );
  		} else if ( str === 'load' ) {
  			return config.LoadScript;
  		} else {
  			return mw.config.get( 'wgScriptPath' ) + '/' + str + '.php';
  		}
  	},
  
  	/**
  	 * Append a new style block to the head and return the CSSStyleSheet object.
  	 * Use .ownerNode to access the `<style>` element, or use mw.loader#addStyleTag.
  	 * This function returns the styleSheet object for convience (due to cross-browsers
  	 * difference as to where it is located).
  	 *
  	 *     var sheet = util.addCSS( '.foobar { display: none; }' );
  	 *     $( foo ).click( function () {
  	 *         // Toggle the sheet on and off
  	 *         sheet.disabled = !sheet.disabled;
  	 *     } );
  	 *
  	 * @param {string} text CSS to be appended
  	 * @return {CSSStyleSheet} Use .ownerNode to get to the `<style>` element.
  	 */
  	addCSS: function ( text ) {
  		var s = mw.loader.addStyleTag( text );
  		return s.sheet;
  	},
  
  	/**
  	 * Grab the URL parameter value for the given parameter.
  	 * Returns null if not found.
  	 *
  	 * @param {string} param The parameter name.
  	 * @param {string} [url=location.href] URL to search through, defaulting to the current browsing location.
  	 * @return {Mixed} Parameter value or null.
  	 */
  	getParamValue: function ( param, url ) {
  		// Get last match, stop at hash
  		var re = new RegExp( '^[^#]*[&?]' + util.escapeRegExp( param ) + '=([^&#]*)' ),
  			m = re.exec( url !== undefined ? url : location.href );
  
  		if ( m ) {
  			// Beware that decodeURIComponent is not required to understand '+'
  			// by spec, as encodeURIComponent does not produce it.
  			return decodeURIComponent( m[ 1 ].replace( /\+/g, '%20' ) );
  		}
  		return null;
  	},
  
  	/**
  	 * The content wrapper of the skin (e.g. `.mw-body`).
  	 *
  	 * Populated on document ready. To use this property,
  	 * wait for `$.ready` and be sure to have a module dependency on
  	 * `mediawiki.util` which will ensure
  	 * your document ready handler fires after initialization.
  	 *
  	 * Because of the lazy-initialised nature of this property,
  	 * you're discouraged from using it.
  	 *
  	 * If you need just the wikipage content (not any of the
  	 * extra elements output by the skin), use `$( '#mw-content-text' )`
  	 * instead. Or listen to mw.hook#wikipage_content which will
  	 * allow your code to re-run when the page changes (e.g. live preview
  	 * or re-render after ajax save).
  	 *
  	 * @property {jQuery}
  	 */
  	$content: null,
  
  	/**
  	 * Add a link to a portlet menu on the page, such as:
  	 *
  	 * p-cactions (Content actions), p-personal (Personal tools),
  	 * p-navigation (Navigation), p-tb (Toolbox)
  	 *
  	 * The first three parameters are required, the others are optional and
  	 * may be null. Though providing an id and tooltip is recommended.
  	 *
  	 * By default the new link will be added to the end of the list. To
  	 * add the link before a given existing item, pass the DOM node
  	 * (e.g. `document.getElementById( 'foobar' )`) or a jQuery-selector
  	 * (e.g. `'#foobar'`) for that item.
  	 *
  	 *     util.addPortletLink(
  	 *         'p-tb', 'https://www.mediawiki.org/',
  	 *         'mediawiki.org', 't-mworg', 'Go to mediawiki.org', 'm', '#t-print'
  	 *     );
  	 *
  	 *     var node = util.addPortletLink(
  	 *         'p-tb',
  	 *         new mw.Title( 'Special:Example' ).getUrl(),
  	 *         'Example'
  	 *     );
  	 *     $( node ).on( 'click', function ( e ) {
  	 *         console.log( 'Example' );
  	 *         e.preventDefault();
  	 *     } );
  	 *
  	 * @param {string} portletId ID of the target portlet (e.g. 'p-cactions' or 'p-personal')
  	 * @param {string} href Link URL
  	 * @param {string} text Link text
  	 * @param {string} [id] ID of the list item, should be unique and preferably have
  	 *  the appropriate prefix ('ca-', 'pt-', 'n-' or 't-')
  	 * @param {string} [tooltip] Text to show when hovering over the link, without accesskey suffix
  	 * @param {string} [accesskey] Access key to activate this link. One character only,
  	 *  avoid conflicts with other links. Use `$( '[accesskey=x]' )` in the console to
  	 *  see if 'x' is already used.
  	 * @param {HTMLElement|jQuery|string} [nextnode] Element that the new item should be added before.
  	 *  Must be another item in the same list, it will be ignored otherwise.
  	 *  Can be specified as DOM reference, as jQuery object, or as CSS selector string.
  	 * @return {HTMLElement|null} The added list item, or null if no element was added.
  	 */
  	addPortletLink: function ( portletId, href, text, id, tooltip, accesskey, nextnode ) {
  		var item, link, $portlet, portlet, portletDiv, ul, next;
  
  		if ( !portletId ) {
  			// Avoid confusing id="undefined" lookup
  			return null;
  		}
  
  		portlet = document.getElementById( portletId );
  		if ( !portlet ) {
  			// Invalid portlet ID
  			return null;
  		}
  
  		// Setup the anchor tag and set any the properties
  		link = document.createElement( 'a' );
  		link.href = href;
  		link.textContent = text;
  
  		if ( tooltip ) {
  			link.title = tooltip;
  		}
  		if ( accesskey ) {
  			link.accessKey = accesskey;
  		}
  
  		// Unhide portlet if it was hidden before
  		$portlet = $( portlet );
  		$portlet.removeClass( 'emptyPortlet' );
  
  		item = $( '<li>' ).append( link )[ 0 ];
  
  		if ( id ) {
  			item.id = id;
  		}
  
  		// Select the first (most likely only) unordered list inside the portlet
  		ul = portlet.tagName.toLowerCase() === 'ul' ? portlet : portlet.querySelector( 'ul' );
  		if ( !ul ) {
  			// If it didn't have an unordered list yet, create one
  			ul = document.createElement( 'ul' );
  			portletDiv = portlet.querySelector( 'div' );
  			if ( portletDiv ) {
  				// Support: Legacy skins have a div (such as div.body or div.pBody).
  				// Append the <ul> to that.
  				portletDiv.appendChild( ul );
  			} else {
  				// Append it to the portlet directly
  				portlet.appendChild( ul );
  			}
  		}
  
  		if ( nextnode && ( typeof nextnode === 'string' || nextnode.nodeType || nextnode.jquery ) ) {
  			// eslint-disable-next-line no-jquery/variable-pattern
  			nextnode = $( ul ).find( nextnode );
  			if ( nextnode.length === 1 && nextnode[ 0 ].parentNode === ul ) {
  				// Insertion point: Before nextnode
  				nextnode.before( item );
  				next = true;
  			}
  			// Else: Invalid nextnode value (no match, more than one match, or not a direct child)
  			// Else: Invalid nextnode type
  		}
  
  		if ( !next ) {
  			// Insertion point: End of list (default)
  			ul.appendChild( item );
  		}
  
  		// Update tooltip for the access key after inserting into DOM
  		// to get a localized access key label (T69946).
  		if ( accesskey ) {
  			$( link ).updateTooltipAccessKeys();
  		}
  
  		mw.hook( 'util.addPortletLink' ).fire( item, {
  			id: id
  		} );
  		return item;
  	},
  
  	/**
  	 * Validate a string as representing a valid e-mail address
  	 * according to HTML5 specification. Please note the specification
  	 * does not validate a domain with one character.
  	 *
  	 * FIXME: should be moved to or replaced by a validation module.
  	 *
  	 * @param {string} mailtxt E-mail address to be validated.
  	 * @return {boolean|null} Null if `mailtxt` was an empty string, otherwise true/false
  	 * as determined by validation.
  	 */
  	validateEmail: function ( mailtxt ) {
  		var rfc5322Atext, rfc1034LdhStr, html5EmailRegexp;
  
  		if ( mailtxt === '' ) {
  			return null;
  		}
  
  		// HTML5 defines a string as valid e-mail address if it matches
  		// the ABNF:
  		//     1 * ( atext / "." ) "@" ldh-str 1*( "." ldh-str )
  		// With:
  		// - atext   : defined in RFC 5322 section 3.2.3
  		// - ldh-str : defined in RFC 1034 section 3.5
  		//
  		// (see STD 68 / RFC 5234 https://tools.ietf.org/html/std68)
  		// First, define the RFC 5322 'atext' which is pretty easy:
  		// atext = ALPHA / DIGIT / ; Printable US-ASCII
  		//     "!" / "#" /    ; characters not including
  		//     "$" / "%" /    ; specials. Used for atoms.
  		//     "&" / "'" /
  		//     "*" / "+" /
  		//     "-" / "/" /
  		//     "=" / "?" /
  		//     "^" / "_" /
  		//     "`" / "{" /
  		//     "|" / "}" /
  		//     "~"
  		rfc5322Atext = 'a-z0-9!#$%&\'*+\\-/=?^_`{|}~';
  
  		// Next define the RFC 1034 'ldh-str'
  		//     <domain> ::= <subdomain> | " "
  		//     <subdomain> ::= <label> | <subdomain> "." <label>
  		//     <label> ::= <letter> [ [ <ldh-str> ] <let-dig> ]
  		//     <ldh-str> ::= <let-dig-hyp> | <let-dig-hyp> <ldh-str>
  		//     <let-dig-hyp> ::= <let-dig> | "-"
  		//     <let-dig> ::= <letter> | <digit>
  		rfc1034LdhStr = 'a-z0-9\\-';
  
  		html5EmailRegexp = new RegExp(
  			// start of string
  			'^' +
  			// User part which is liberal :p
  			'[' + rfc5322Atext + '\\.]+' +
  			// 'at'
  			'@' +
  			// Domain first part
  			'[' + rfc1034LdhStr + ']+' +
  			// Optional second part and following are separated by a dot
  			'(?:\\.[' + rfc1034LdhStr + ']+)*' +
  			// End of string
  			'$',
  			// RegExp is case insensitive
  			'i'
  		);
  		return ( mailtxt.match( html5EmailRegexp ) !== null );
  	},
  
  	/**
  	 * Note: borrows from \Wikimedia\IPUtils::isIPv4
  	 *
  	 * @param {string} address
  	 * @param {boolean} [allowBlock=false]
  	 * @return {boolean}
  	 */
  	isIPv4Address: function ( address, allowBlock ) {
  		var block,
  			RE_IP_BYTE = '(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|0?[0-9]?[0-9])',
  			RE_IP_ADD = '(?:' + RE_IP_BYTE + '\\.){3}' + RE_IP_BYTE;
  
  		if ( typeof address !== 'string' ) {
  			return false;
  		}
  
  		block = allowBlock ? '(?:\\/(?:3[0-2]|[12]?\\d))?' : '';
  
  		return ( new RegExp( '^' + RE_IP_ADD + block + '$' ).test( address ) );
  	},
  
  	/**
  	 * Note: borrows from \Wikimedia\IPUtils::isIPv6
  	 *
  	 * @param {string} address
  	 * @param {boolean} [allowBlock=false]
  	 * @return {boolean}
  	 */
  	isIPv6Address: function ( address, allowBlock ) {
  		var block, RE_IPV6_ADD;
  
  		if ( typeof address !== 'string' ) {
  			return false;
  		}
  
  		block = allowBlock ? '(?:\\/(?:12[0-8]|1[01][0-9]|[1-9]?\\d))?' : '';
  		RE_IPV6_ADD =
  			'(?:' + // starts with "::" (including "::")
  				':(?::|(?::' +
  					'[0-9A-Fa-f]{1,4}' +
  				'){1,7})' +
  				'|' + // ends with "::" (except "::")
  				'[0-9A-Fa-f]{1,4}' +
  				'(?::' +
  					'[0-9A-Fa-f]{1,4}' +
  				'){0,6}::' +
  				'|' + // contains no "::"
  				'[0-9A-Fa-f]{1,4}' +
  				'(?::' +
  					'[0-9A-Fa-f]{1,4}' +
  				'){7}' +
  			')';
  
  		if ( new RegExp( '^' + RE_IPV6_ADD + block + '$' ).test( address ) ) {
  			return true;
  		}
  
  		// contains one "::" in the middle (single '::' check below)
  		RE_IPV6_ADD =
  			'[0-9A-Fa-f]{1,4}' +
  			'(?:::?' +
  				'[0-9A-Fa-f]{1,4}' +
  			'){1,6}';
  
  		return (
  			new RegExp( '^' + RE_IPV6_ADD + block + '$' ).test( address ) &&
  			/::/.test( address ) &&
  			!/::.*::/.test( address )
  		);
  	},
  
  	/**
  	 * Check whether a string is an IP address
  	 *
  	 * @since 1.25
  	 * @param {string} address String to check
  	 * @param {boolean} [allowBlock=false] If a block of IPs should be allowed
  	 * @return {boolean}
  	 */
  	isIPAddress: function ( address, allowBlock ) {
  		return util.isIPv4Address( address, allowBlock ) ||
  			util.isIPv6Address( address, allowBlock );
  	},
  
  	/**
  	 * Parse the URL of an image uploaded to MediaWiki, or a thumbnail for such an image,
  	 * and return the image name, thumbnail size and a template that can be used to resize
  	 * the image.
  	 *
  	 * @param {string} url URL to parse (URL-encoded)
  	 * @return {Object|null} URL data, or null if the URL is not a valid MediaWiki
  	 *   image/thumbnail URL.
  	 * @return {string} return.name File name (same format as Title.getMainText()).
  	 * @return {number} [return.width] Thumbnail width, in pixels. Null when the file is not
  	 *   a thumbnail.
  	 * @return {function(number):string} [return.resizeUrl] A function that takes a width
  	 *   parameter and returns a thumbnail URL (URL-encoded) with that width. The width
  	 *   parameter must be smaller than the width of the original image (or equal to it; that
  	 *   only works if MediaHandler::mustRender returns true for the file). Null when the
  	 *   file in the original URL is not a thumbnail.
  	 *   On wikis with $wgGenerateThumbnailOnParse set to true, this will fall back to using
  	 *   Special:Redirect which is less efficient. Otherwise, it is a direct thumbnail URL.
  	 */
  	parseImageUrl: function ( url ) {
  		var i, name, decodedName, width, match, strippedUrl,
  			urlTemplate = null,
  			// thumb.php-generated thumbnails
  			// thumb.php?f=<name>&w[idth]=<width>[px]
  			thumbPhpRegex = /thumb\.php/,
  			regexes = [
  				// Thumbnails
  				// /<hash prefix>/<name>/[<options>-]<width>-<name*>[.<ext>]
  				// where <name*> could be the filename, 'thumbnail.<ext>' (for long filenames)
  				// or the base-36 SHA1 of the filename.
  				/\/[\da-f]\/[\da-f]{2}\/([^\s/]+)\/(?:[^\s/]+-)?(\d+)px-(?:\1|thumbnail|[a-z\d]{31})(\.[^\s/]+)?$/,
  
  				// Full size images
  				// /<hash prefix>/<name>
  				/\/[\da-f]\/[\da-f]{2}\/([^\s/]+)$/,
  
  				// Thumbnails in non-hashed upload directories
  				// /<name>/[<options>-]<width>-<name*>[.<ext>]
  				/\/([^\s/]+)\/(?:[^\s/]+-)?(\d+)px-(?:\1|thumbnail|[a-z\d]{31})[^\s/]*$/,
  
  				// Full-size images in non-hashed upload directories
  				// /<name>
  				/\/([^\s/]+)$/
  			];
  
  		if ( thumbPhpRegex.test( url ) ) {
  			decodedName = mw.util.getParamValue( 'f', url );
  			name = encodeURIComponent( decodedName );
  			width = mw.util.getParamValue( 'width', url ) || mw.util.getParamValue( 'w', url );
  			urlTemplate = url.replace( /([&?])w(?:idth)?=[^&]+/g, '' ) + '&width={width}';
  		} else {
  			for ( i = 0; i < regexes.length; i++ ) {
  				match = url.match( regexes[ i ] );
  				if ( match ) {
  					name = match[ 1 ];
  					decodedName = decodeURIComponent( name );
  					width = match[ 2 ] || null;
  					break;
  				}
  			}
  		}
  
  		if ( name ) {
  			if ( width !== null ) {
  				width = parseInt( width, 10 ) || null;
  			}
  			if ( config.GenerateThumbnailOnParse ) {
  				// The wiki cannot generate thumbnails on demand. Use a special page - this means
  				// an extra redirect and PHP request, but it will generate the thumbnail if it does
  				// not exist.
  				urlTemplate = mw.util.getUrl( 'Special:Redirect/file/' + decodedName, { width: '{width}' } )
  					// getUrl urlencodes the template variable, fix that
  					.replace( '%7Bwidth%7D', '{width}' );
  			} else if ( width && !urlTemplate ) {
  				// Javascript does not expose regexp capturing group indexes, and the width
  				// part could in theory also occur in the filename so hide that first.
  				strippedUrl = url.replace( name, '{name}' )
  					.replace( name, '{name}' )
  					.replace( width + 'px-', '{width}px-' );
  				urlTemplate = strippedUrl.replace( /\{name\}/g, name );
  			}
  			return {
  				name: decodedName.replace( /_/g, ' ' ),
  				width: width,
  				resizeUrl: urlTemplate ? function ( w ) {
  					return urlTemplate.replace( '{width}', w );
  				} : null
  			};
  		}
  		return null;
  	},
  
  	/**
  	 * Escape string for safe inclusion in regular expression
  	 *
  	 * The following characters are escaped:
  	 *
  	 *     \ { } ( ) | . ? * + - ^ $ [ ]
  	 *
  	 * @since 1.26; moved to mw.util in 1.34
  	 * @param {string} str String to escape
  	 * @return {string} Escaped string
  	 */
  	escapeRegExp: function ( str ) {
  		// eslint-disable-next-line no-useless-escape
  		return str.replace( /([\\{}()|.?*+\-^$\[\]])/g, '\\$1' );
  	}
  };
  
  /**
   * Initialisation of mw.util.$content
   *
   * @ignore
   */
  function init() {
  	// The preferred standard is class "mw-body".
  	// You may also use class "mw-body mw-body-primary" if you use
  	// mw-body in multiple locations. Or class "mw-body-primary" if
  	// you use mw-body deeper in the DOM.
  	var content = document.querySelector( '.mw-body-primary' ) ||
  		document.querySelector( '.mw-body' ) ||
  		// If the skin has no such class, fall back to the parser output
  		document.querySelector( '#mw-content-text' ) ||
  		// Should never happen..., except if the skin is still in development.
  		document.body;
  
  	util.$content = $( content );
  }
  
  // Backwards-compatible alias for mediawiki.RegExp module.
  // @deprecated since 1.34
  mw.RegExp = {};
  mw.log.deprecate( mw.RegExp, 'escape', util.escapeRegExp, 'Use mw.util.escapeRegExp() instead.', 'mw.RegExp.escape' );
  
  if ( window.QUnit ) {
  	// Not allowed outside unit tests
  	util.setOptionsForTest = function ( opts ) {
  		var oldConfig = config;
  		config = $.extend( {}, config, opts );
  		return oldConfig;
  	};
  	util.init = init;
  } else {
  	$( init );
  }
  
  mw.util = util;
  module.exports = util;
  