🐛 notify deferred resource events synchronously after delay

The deferred setTimeout path used handleResource which routes through the
task queue's requestIdleCallback. That callback can fire after the click
action's PAGE_ACTIVITY_END_DELAY window closes, leaving the resource
uncounted by its parent action. Notify the lifecycle synchronously once
the matching delay elapses so the resource is attributed correctly.

Author: thomas-lebeau

packages/rum-core/src/domain/resource/resourceCollection.ts

@@ -62,12 +62,19 @@ export function startResourceCollection(lifeCycle: LifeCycle, configuration: Rum
         // (notably on Firefox), so the matching REQUEST_COMPLETED isn't in the registry yet.
         // Defer the lookup to give the request time to land before we look it up.
         //
+        // Publish synchronously after the delay rather than via the task queue: the queue's
+        // requestIdleCallback can fire after the click action's PAGE_ACTIVITY_END_DELAY window
+        // (notably on newer Chromium scheduling), leaving the request uncounted by its parent
+        // action.
+        //
         // Note: we could clear the timeout on stop(), but this requires a bit of bookkeeping that
         // is not necessary right now. We could reevaluate in the future.
-        setTimeout(
-          () => handleResource(() => assembleResource(entry, requestRegistry.getMatchingRequest(entry), configuration)),
-          REQUEST_MATCHING_DELAY
-        )
+        setTimeout(() => {
+          const rawEvent = assembleResource(entry, requestRegistry.getMatchingRequest(entry), configuration)
+          if (rawEvent) {
+            lifeCycle.notify(LifeCycleEventType.RAW_RUM_EVENT_COLLECTED, rawEvent)
+          }
+        }, REQUEST_MATCHING_DELAY)
       } else {
         handleResource(() => assembleResource(entry, undefined, configuration))
       }