Enabling spy when checking for hiddenContentSize

lib/tools/phantomas/custom_modules/modules/domHiddenYLT/domHiddenYLT.js

@@ -0,0 +1,50 @@
+/**
+ * Analyzes DOM hidden content
+ */
+/* global document: true, Node: true, window: true */
+
+exports.version = '0.1.a';
+
+exports.module = function(phantomas) {
+    'use strict';
+
+    // total length of HTML of hidden elements (i.e. display: none)
+    phantomas.setMetric('hiddenContentSize'); // @desc the size of content of hidden elements on the page (with CSS display: none) @offenders
+
+    // HTML size
+    phantomas.on('report', function() {
+        phantomas.evaluate(function() {
+            (function(phantomas) {
+                phantomas.spyEnabled(false, 'checking the hiddenContentSize');
+
+                var runner = new phantomas.nodeRunner();
+
+                runner.walk(document.body, function(node, depth) {
+                    switch (node.nodeType) {
+                        case Node.ELEMENT_NODE:
+                            // @see https://developer.mozilla.org/en/DOM%3awindow.getComputedStyle
+                            var styles = window.getComputedStyle(node);
+
+                            if (styles && styles.getPropertyValue('display') === 'none') {
+                                if (typeof node.innerHTML === 'string') {
+                                    var size = node.innerHTML.length;
+                                    phantomas.incrMetric('hiddenContentSize', size);
+
+                                    // log hidden containers bigger than 1 kB
+                                    if (size > 1024) {
+                                        phantomas.addOffender('hiddenContentSize', phantomas.getDOMPath(node) + ' (' + size + ' characters)');
+                                    }
+                                }
+
+                                // don't run for child nodes as they're hidden as well
+                                return false;
+                            }
+                            break;
+                    }
+                });
+
+                phantomas.spyEnabled(true);
+            }(window.__phantomas));
+        });
+    });
+};

lib/tools/phantomas/phantomasWrapper.js

@@ -35,6 +35,7 @@ var PhantomasWrapper = function() {
             'analyze-css': true,
             'skip-modules': [
                 'blockDomains', // not needed
+                'domHiddenContent', // overriden
                 'domMutations', // not compatible with webkit
                 'domQueries', // overriden
                 'eventListeners', // overridden