WIP: An oddity in that it has a .sheet in the mutation , before the l…

…oad event ... what if the load event has already fired in some browsers (or if the mutation event is delayed)

packages/rrweb/src/record/mutation.ts

@@ -669,6 +669,11 @@ export default class MutationBuffer {
             value.toLowerCase() === 'stylesheet' &&
             m.target.tagName === 'LINK'
           ) {
+            if (m.target.sheet) {
+              console.warn(
+                'have we missed the onload event due to delayed mutation?',
+              );
+            }
             this.stylesheetManager.trackLinkElement(
               m.target as HTMLLinkElement,
             );

packages/rrweb/src/record/stylesheet-manager.ts

@@ -70,6 +70,7 @@ export class StylesheetManager {
     // if <link> is already loaded, it will have .sheet available and that
     // will get serialized in the snapshot. The following is for when that doesn't happen
     linkEl.addEventListener('load', () => {
+      console.log('load');
       if (!linkEl.sheet) {
         return;
       }
@@ -80,6 +81,7 @@ export class StylesheetManager {
       }
       let _cssText = stringifyStylesheet(linkEl.sheet);
       if (_cssText) {
+        console.log('load emit');
         _cssText = absoluteToStylesheet(
           _cssText,
           getHref(linkEl.ownerDocument),