Performance 2022: CWV gaming

dist/performance.js

@@ -84,6 +84,66 @@ function getWebVitalsJS() {
     }).map(har => har.url);
 }
 
+function getGamingMetrics(rawDoc) {
+    let returnObj = {};
+    const regexForCheckChromeLH = new RegExp(/.{1}userAgent.{1,100}(?:Chrome-Lighthouse|Google Lighthouse).{2}/)
+    const regexForCheckGTmetrix = new RegExp(/.{1}userAgent.{1,100}(?:GTmetrix|gtmetrix.com).{2}/)
+    const regexForCheckPageSpeed = new RegExp(/.{1}userAgent.{1,100}(?:PageSpeed).{2}/)
+    let scripts = rawDoc.getElementsByTagName('script');
+    for (let i = 0; i < scripts.length; i++) {
+        if (scripts[i].src) {
+            continue;
+        }
+        let scriptTagCode = scripts[i].innerHTML;
+        if (regexForCheckChromeLH.test(scriptTagCode)){
+            returnObj['detectUA-ChromeLH'] = true;
+        }
+        if(regexForCheckGTmetrix.test(scriptTagCode)){
+            returnObj['detectUA-GTmetrix'] = true;
+        }
+        if(regexForCheckPageSpeed.test(scriptTagCode)){
+            returnObj['detectUA-PageSpeed'] = true;
+        }
+    }
+
+    //https://www.debugbear.com/blog/optimizing-web-vitals-without-improving-performance
+    //catch lcp animation / cls animation & overlay hack
+    const regexForCheckfadeInAnimation = new RegExp(/this.style.animation.{1,10}.fadein.{1,20}.forwards/)
+    let elements = rawDoc.getElementsByTagName('img');
+    for (let i = 0; i < elements.length; i++) {
+        let el = elements[i];
+        let onloadVal = el.getAttribute('onload');
+        if (onloadVal !== null) {
+            if(regexForCheckfadeInAnimation.test(onloadVal)) {
+                returnObj['lcpAnimation'] = true;
+            }
+        }
+        let styleObj = el.style;
+        if (styleObj['pointer-events'] == 'none' &&
+                styleObj['position'] == 'absolute' &&
+                styleObj['width'] == '99vw' &&
+                styleObj['height'] == '99vh') {
+            returnObj['lcpOverlay'] = true;
+        }
+    }
+
+    //add logic for svg & body overlay
+    let svgTags = rawDoc.getElementsByTagName('svg');
+    for (let i = 0; i < svgTags.length; i++) {
+        const svg = svgTags[i];
+        if (svg.clientHeight == 99999 &&
+                svg.clientWidth == 99999 &&
+                svg.clientLeft == 0 &&
+                svg.clientTop == 0) {
+            //additional check required
+            returnObj['lcpSvgOverlay'] = true;
+        }
+    }
+    //fid iframe hack
+
+    return returnObj;
+}
+
 return Promise.all([getLcpElement()]).then(([lcp_elem_stats]) => {
     const lcpUrl = lcp_elem_stats.url;
     const rawDoc = getRawHtmlDocument();
@@ -121,7 +181,8 @@ return Promise.all([getLcpElement()]).then(([lcp_elem_stats]) => {
         lcp_resource: responseObject,
         is_lcp_statically_discoverable: isLcpStaticallyDiscoverable,
         is_lcp_preloaded: isLcpPreloaded,
-        web_vitals_js: getWebVitalsJS()
+        web_vitals_js: getWebVitalsJS(),
+        gamingMetrics: getGamingMetrics(rawDoc)
     };
 }).catch(error => {
     return {error};