add a new "dirty" flag to session

Author: billyvg

packages/replay-internal/src/coreHandlers/handleGlobalEvent.ts

@@ -71,15 +71,16 @@ export function handleGlobalEventListener(replay: ReplayContainer): (event: Even
       }
 
       // If we sampled this error in buffer mode, immediately mark the session as "sampled"
-      // by changing the sampled state from 'buffer' to 'session'. Otherwise, if the application is interrupted before `afterSendEvent` occurs, then the session would remain as "buffer" but we have an error event that is tagged with a replay id. This could end up creating replays w/ excessive durations because of the linked error.
-      if (isErrorEventSampled && replay.recordingMode === 'buffer') {
+      // by changing the sampled state from 'buffer' to 'session'. Otherwise, if the application is interrupte
+      // before `afterSendEvent` occurs, then the session would remain as "buffer" but we have an error event
+      // that is tagged with a replay id. This could end up creating replays w/ excessive durations because
+      // of the linked error.
+      if (isErrorEventSampled && replay.recordingMode === 'buffer' && replay.session?.sampled === 'buffer') {
         const session = replay.session;
-        if (session?.sampled === 'buffer') {
-          session.sampled = 'session';
-          // Save the session if sticky sessions are enabled to persist the state change
-          if (replay.getOptions().stickySession) {
-            saveSession(session);
-          }
+        session.dirty = true;
+        // Save the session if sticky sessions are enabled to persist the state change
+        if (replay.getOptions().stickySession) {
+          saveSession(session);
         }
       }
 

packages/replay-internal/src/types/replay.ts

@@ -383,6 +383,13 @@ export interface Session {
    * Is the session sampled? `false` if not sampled, otherwise, `session` or `buffer`
    */
   sampled: Sampled;
+
+  /**
+   * Session is dirty when its id has been linked to an event (e.g. error event).
+   * This is helpful when a session is mistakenly stuck in "buffer" mode (e.g. network issues preventing it from being converted to "session" mode).
+   * The dirty flag is used to prevent updating the session start time to the earliest event in the buffer so that it can be refreshed if it's been expired.
+   */
+  dirty?: boolean;
 }
 
 export type EventBufferType = 'sync' | 'worker';

packages/replay-internal/src/util/handleRecordingEmit.ts

@@ -72,7 +72,7 @@ export function getHandleRecordingEmit(replay: ReplayContainer): RecordingEmitCa
 
       // When in buffer mode, make sure we adjust the session started date to the current earliest event of the buffer
       // this should usually be the timestamp of the checkout event, but to be safe...
-      if (replay.recordingMode === 'buffer' && session && replay.eventBuffer) {
+      if (replay.recordingMode === 'buffer' && session && replay.eventBuffer && !session.dirty) {
         const earliestEvent = replay.eventBuffer.getEarliestTimestamp();
         if (earliestEvent) {
           DEBUG_BUILD &&