1 files changed, 204 insertions, 0 deletions
diff --git a/resources/mediawiki/mediawiki.inspect.js b/resources/mediawiki/mediawiki.inspect.js
new file mode 100644
index 00000000..2f2ca335
--- /dev/null
+++ b/resources/mediawiki/mediawiki.inspect.js
@@ -0,0 +1,204 @@
+/*!
+ * Tools for inspecting page composition and performance.
+ *
+ * @author Ori Livneh
+ * @since 1.22
+ */
+/*jshint devel:true */
+( function ( mw, $ ) {
+
+	function sortByProperty( array, prop, descending ) {
+		var order = descending ? -1 : 1;
+		return array.sort( function ( a, b ) {
+			return a[prop] > b[prop] ? order : a[prop] < b[prop] ? -order : 0;
+		} );
+	}
+
+	/**
+	 * @class mw.inspect
+	 * @singleton
+	 */
+	var inspect = {
+
+		/**
+		 * Calculate the byte size of a ResourceLoader module.
+		 *
+		 * @param {string} moduleName The name of the module
+		 * @return {number|null} Module size in bytes or null
+		 */
+		getModuleSize: function ( moduleName ) {
+			var module = mw.loader.moduleRegistry[ moduleName ],
+				payload = 0;
+
+			if ( mw.loader.getState( moduleName ) !== 'ready' ) {
+				return null;
+			}
+
+			if ( !module.style && !module.script ) {
+				return null;
+			}
+
+			// Tally CSS
+			if ( module.style && $.isArray( module.style.css ) ) {
+				$.each( module.style.css, function ( i, stylesheet ) {
+					payload += $.byteLength( stylesheet );
+				} );
+			}
+
+			// Tally JavaScript
+			if ( $.isFunction( module.script ) ) {
+				payload += $.byteLength( module.script.toString() );
+			}
+
+			return payload;
+		},
+
+		/**
+		 * Given CSS source, count both the total number of selectors it
+		 * contains and the number which match some element in the current
+		 * document.
+		 *
+		 * @param {string} css CSS source
+		 * @return Selector counts
+		 * @return {number} return.selectors Total number of selectors
+		 * @return {number} return.matched Number of matched selectors
+		 */
+		auditSelectors: function ( css ) {
+			var selectors = { total: 0, matched: 0 },
+				style = document.createElement( 'style' ),
+				sheet, rules;
+
+			style.textContent = css;
+			document.body.appendChild( style );
+			// Standards-compliant browsers use .sheet.cssRules, IE8 uses .styleSheet.rules…
+			sheet = style.sheet || style.styleSheet;
+			rules = sheet.cssRules || sheet.rules;
+			$.each( rules, function ( index, rule ) {
+				selectors.total++;
+				if ( document.querySelector( rule.selectorText ) !== null ) {
+					selectors.matched++;
+				}
+			} );
+			document.body.removeChild( style );
+			return selectors;
+		},
+
+		/**
+		 * Get a list of all loaded ResourceLoader modules.
+		 *
+		 * @return {Array} List of module names
+		 */
+		getLoadedModules: function () {
+			return $.grep( mw.loader.getModuleNames(), function ( module ) {
+				return mw.loader.getState( module ) === 'ready';
+			} );
+		},
+
+		/**
+		 * Print tabular data to the console, using console.table, console.log,
+		 * or mw.log (in declining order of preference).
+		 *
+		 * @param {Array} data Tabular data represented as an array of objects
+		 *  with common properties.
+		 */
+		dumpTable: function ( data ) {
+			try {
+				// Bartosz made me put this here.
+				if ( window.opera ) { throw window.opera; }
+				// Use Function.prototype#call to force an exception on Firefox,
+				// which doesn't define console#table but doesn't complain if you
+				// try to invoke it.
+				console.table.call( console, data );
+				return;
+			} catch (e) {}
+			try {
+				console.log( $.toJSON( data, null, 2 ) );
+				return;
+			} catch (e) {}
+			mw.log( data );
+		},
+
+		/**
+		 * Generate and print one more reports. When invoked with no arguments,
+		 * print all reports.
+		 *
+		 * @param {string...} [reports] Report names to run, or unset to print
+		 *  all available reports.
+		 */
+		runReports: function () {
+			var reports = arguments.length > 0 ?
+				Array.prototype.slice.call( arguments ) :
+				$.map( inspect.reports, function ( v, k ) { return k; } );
+
+			$.each( reports, function ( index, name ) {
+				inspect.dumpTable( inspect.reports[name]() );
+			} );
+		},
+
+		/**
+		 * @class mw.inspect.reports
+		 * @singleton
+		 */
+		reports: {
+			/**
+			 * Generate a breakdown of all loaded modules and their size in
+			 * kilobytes. Modules are ordered from largest to smallest.
+			 */
+			size: function () {
+				// Map each module to a descriptor object.
+				var modules = $.map( inspect.getLoadedModules(), function ( module ) {
+					return {
+						name: module,
+						size: inspect.getModuleSize( module )
+					};
+				} );
+
+				// Sort module descriptors by size, largest first.
+				sortByProperty( modules, 'size', true );
+
+				// Convert size to human-readable string.
+				$.each( modules, function ( i, module ) {
+					module.size = module.size > 1024 ?
+						( module.size / 1024 ).toFixed( 2 ) + ' KB' :
+						( module.size !== null ? module.size + ' B' : null );
+				} );
+
+				return modules;
+			},
+
+			/**
+			 * For each module with styles, count the number of selectors, and
+			 * count how many match against some element currently in the DOM.
+			 */
+			css: function () {
+				var modules = [];
+
+				$.each( inspect.getLoadedModules(), function ( index, name ) {
+					var css, stats, module = mw.loader.moduleRegistry[name];
+
+					try {
+						css = module.style.css.join();
+					} catch (e) { return; } // skip
+
+					stats = inspect.auditSelectors( css );
+					modules.push( {
+						module: name,
+						allSelectors: stats.total,
+						matchedSelectors: stats.matched,
+						percentMatched: stats.total !== 0 ?
+							( stats.matched / stats.total * 100 ).toFixed( 2 )  + '%' : null
+					} );
+				} );
+				sortByProperty( modules, 'allSelectors', true );
+				return modules;
+			},
+		}
+	};
+
+	if ( mw.config.get( 'debug' ) ) {
+		mw.log( 'mw.inspect: reports are not available in debug mode.' );
+	}
+
+	mw.inspect = inspect;
+
+}( mediaWiki, jQuery ) );