[fix]: clean up cdp session event handlers

.changeset/petite-rocks-lead.md

@@ -0,0 +1,5 @@
+---
+"@browserbasehq/stagehand": patch
+---
+
+clean up cdp session event handlers on target detach

packages/core/lib/v3/understudy/cdp.ts

@@ -208,6 +208,40 @@ export class CdpConnection implements CDPSessionLike {
     }
   }
 
+  private clearSessionEventHandlers(sessionId: string): void {
+    const prefix = `${sessionId}:`;
+    for (const key of Array.from(this.eventHandlers.keys())) {
+      if (key.startsWith(prefix)) {
+        this.eventHandlers.delete(key);
+      }
+    }
+  }
+
+  private rejectSessionPendingWork(
+    sessionId: string,
+    targetId: string | null,
+  ): void {
+    for (const [id, entry] of this.inflight.entries()) {
+      if (entry.sessionId === sessionId) {
+        entry.reject(
+          new PageNotFoundError(
+            `target closed before CDP response (sessionId=${sessionId}, targetId=${targetId})`,
+          ),
+        );
+        this.inflight.delete(id);
+      }
+    }
+    for (const waiter of Array.from(this.sessionDispatchWaiters)) {
+      if (waiter.sessionId === sessionId) {
+        waiter.reject(
+          new PageNotFoundError(
+            `target closed before CDP send (sessionId=${sessionId}, targetId=${targetId})`,
+          ),
+        );
+      }
+    }
+  }
+
   getSession(sessionId: string): CdpSession | undefined {
     return this.sessions.get(sessionId);
   }
@@ -334,25 +368,8 @@ export class CdpConnection implements CDPSessionLike {
       } else if (msg.method === "Target.detachedFromTarget") {
         const p = (msg as { params: Protocol.Target.DetachedFromTargetEvent })
           .params;
-        for (const [id, entry] of this.inflight.entries()) {
-          if (entry.sessionId === p.sessionId) {
-            entry.reject(
-              new PageNotFoundError(
-                `target closed before CDP response (sessionId=${p.sessionId}, targetId=${p.targetId})`,
-              ),
-            );
-            this.inflight.delete(id);
-          }
-        }
-        for (const waiter of Array.from(this.sessionDispatchWaiters)) {
-          if (waiter.sessionId === p.sessionId) {
-            waiter.reject(
-              new PageNotFoundError(
-                `target closed before CDP send (sessionId=${p.sessionId}, targetId=${p.targetId})`,
-              ),
-            );
-          }
-        }
+        this.rejectSessionPendingWork(p.sessionId, p.targetId ?? null);
+        this.clearSessionEventHandlers(p.sessionId);
         this.sessions.delete(p.sessionId);
         this.sessionToTarget.delete(p.sessionId);
         this.latestCdpCallEvent.delete(p.sessionId);
@@ -361,9 +378,11 @@ export class CdpConnection implements CDPSessionLike {
         // Remove any session mapping for this target
         for (const [sessionId, targetId] of this.sessionToTarget.entries()) {
           if (targetId === p.targetId) {
+            this.rejectSessionPendingWork(sessionId, p.targetId);
+            this.clearSessionEventHandlers(sessionId);
+            this.sessions.delete(sessionId);
             this.sessionToTarget.delete(sessionId);
             this.latestCdpCallEvent.delete(sessionId);
-            break;
           }
         }
       }