Temporary fix for relative lazyloadable images src

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

@@ -0,0 +1,78 @@
+/**
+ * Analyzes images and detects which one can be lazy-loaded (are below the fold)
+ *
+ * @see https://github.com/macbre/phantomas/issues/494
+ */
+/* global document: true, window: true */
+'use strict';
+
+exports.version = '1.0.a';
+
+exports.module = function(phantomas) {
+    phantomas.setMetric('lazyLoadableImagesBelowTheFold'); // @desc number of images displayed below the fold that can be lazy-loaded
+
+    phantomas.on('report', function() {
+        phantomas.log('lazyLoadableImages: analyzing which images can be lazy-loaded...');
+
+        phantomas.evaluate(function() {
+            (function(phantomas) {
+                phantomas.spyEnabled(false, 'analyzing which images can be lazy-loaded');
+
+                var images = document.body.getElementsByTagName('img'),
+                    i,
+                    len = images.length,
+                    offset,
+                    path,
+                    processedImages = {},
+                    src,
+                    viewportHeight = window.innerHeight;
+
+                phantomas.log('lazyLoadableImages: %d image(s) found, assuming %dpx offset to be the fold', len, viewportHeight);
+
+                for (i = 0; i < len; i++) {
+                    // @see https://developer.mozilla.org/en-US/docs/Web/API/Element/getBoundingClientRect
+                    offset = images[i].getBoundingClientRect().top;
+                    src = images[i].src;
+
+                    // ignore base64-encoded images
+                    if (src === '' || /^data:/.test(src)) {
+                        continue;
+                    }
+
+                    path = phantomas.getDOMPath(images[i]);
+
+                    // get the most top position for a given image (deduplicate by src)
+                    if (typeof processedImages[src] === 'undefined') {
+                        processedImages[src] = {
+                            offset: offset,
+                            path: path
+                        };
+                    }
+
+                    // maybe there's the same image loaded above the fold?
+                    if (offset < processedImages[src].offset) {
+                        processedImages[src] = {
+                            offset: offset,
+                            path: path
+                        };
+                    }
+                }
+
+                phantomas.log('lazyLoadableImages: checking %d unique image(s)', Object.keys(processedImages).length);
+
+                Object.keys(processedImages).forEach(function(src) {
+                    var img = processedImages[src];
+
+                    if (img.offset > viewportHeight) {
+                        phantomas.log('lazyLoadableImages: <%s> image (%s) is below the fold (at %dpx)', src, img.path, img.offset);
+
+                        phantomas.incrMetric('lazyLoadableImagesBelowTheFold');
+                        phantomas.addOffender('lazyLoadableImagesBelowTheFold', src);
+                    }
+                });
+
+                phantomas.spyEnabled(true);
+            })(window.__phantomas);
+        });
+    });
+};

lib/tools/phantomas/phantomasWrapper.js

@@ -46,6 +46,7 @@ var PhantomasWrapper = function() {
                 'javaScriptBottlenecks', // needs to be launched after custom module scopeYLT
                 'jQuery', // overridden
                 'jserrors', // overridden
+                'lazyLoadableImages', //overriden
                 'pageSource', // not needed
                 'windowPerformance' // overriden
             ].join(','),