---
phase: 22-session-screen-fixes
verified: 2026-02-08T17:30:00Z
status: passed
score: 3/3 must-haves verified
---

# Phase 22: Session Screen Fixes Verification Report

**Phase Goal:** Fix identified session screen useEffect and polling cleanup issues
**Verified:** 2026-02-08T17:30:00Z
**Status:** passed
**Re-verification:** No - initial verification

## Goal Achievement

### Observable Truths

| # | Truth | Status | Evidence |
|---|-------|--------|----------|
| 1 | Session screen cleanup runs on component unmount regardless of leave handler execution | VERIFIED | useEffect cleanup at line 940-957 calls `unregisterMessageCallbacks()` which uses `registeredCallbacksRef.current` |
| 2 | Callback registration uses refs to ensure cleanup always has access to current callbacks | VERIFIED | `registeredCallbacksRef` declared at line 294, used in `unregisterMessageCallbacks` at line 299 |
| 3 | Session can be exited via any path (leave button, navigation, browser close) without leaking callbacks | VERIFIED | Three exit paths covered: (1) Leave button calls `unregisterMessageCallbacks()` at line 899, (2) Navigation/unmount triggers cleanup useEffect return at line 941-943, (3) Browser close handled by server-side connection cleanup |

**Score:** 3/3 truths verified

### Required Artifacts

| Artifact | Expected | Status | Details |
|----------|----------|--------|---------|
| `jam-ui/src/components/client/JKSessionScreen.js` | Improved callback cleanup with useRef | VERIFIED | `registeredCallbacksRef` at line 294, used in `unregisterMessageCallbacks()` at line 299, registration stores to both state and ref at lines 633-634 |

### Key Link Verification

| From | To | Via | Status | Details |
|------|-----|-----|--------|---------|
| JKSessionScreen cleanup useEffect | unregisterMessageCallback | registeredCallbacksRef.current | WIRED | Line 299: `const callbacks = registeredCallbacksRef.current;` followed by iteration and unregistration at lines 300-301 |
| Callback registration | Both state and ref | setRegisteredCallbacks + ref assignment | WIRED | Lines 633-634: `setRegisteredCallbacks(callbacksToRegister);` and `registeredCallbacksRef.current = callbacksToRegister;` |
| Leave handler | unregisterMessageCallbacks | Direct call | WIRED | Line 899: `unregisterMessageCallbacks();` called before leaving session |

### Requirements Coverage

| Requirement | Status | Notes |
|-------------|--------|-------|
| SESS-01 | SATISFIED | useRef pattern implemented for reliable callback cleanup on all exit paths |
| SESS-02 | SATISFIED | Phase 19 audit verified useJamServer.js, useSessionStats.js timers already have proper cleanup |
| SESS-03 | SATISFIED | Phase 19 audit verified useJamServer.js event listeners already have proper cleanup |

### Anti-Patterns Found

| File | Line | Pattern | Severity | Impact |
|------|------|---------|----------|--------|
| None found | - | - | - | No stub patterns, TODOs, or placeholder content in modified code |

### Human Verification Required

None required - all verification criteria can be confirmed through static code analysis.

### Success Criteria Verification

From ROADMAP.md:

| # | Criterion | Status | Evidence |
|---|-----------|--------|----------|
| 1 | All useEffect hooks that set up subscriptions/intervals have cleanup return functions | VERIFIED | JKSessionScreen.js cleanup useEffect at line 940-957; useJamServer.js, useSessionStats.js, useSessionModel.js all have proper cleanup (per Phase 19 audit) |
| 2 | All polling intervals are cleared on component unmount | VERIFIED | useSessionStats.js line 153 `return () => clearInterval(interval);`; useJamServer.js has comprehensive timer cleanup |
| 3 | All event listeners have corresponding removal on cleanup | VERIFIED | useJamServer.js lines 644-651 removes activity event listeners; no new listeners added |
| 4 | Session screen can be mounted/unmounted without memory growth | VERIFIED (code) | Cleanup patterns ensure callbacks and state are cleared; full runtime verification deferred to Phase 23 |
| 5 | No orphaned polling or listeners accumulate during normal session use | VERIFIED (code) | All timer and listener patterns reviewed; no accumulation patterns found |

### Summary

Phase 22 goal achieved. The session screen callback cleanup has been hardened with the useRef pattern to ensure reliable cleanup on all exit paths:

1. **SESS-01 addressed:** Added `registeredCallbacksRef` alongside `registeredCallbacks` state. The `unregisterMessageCallbacks` function now reads from the ref rather than state, avoiding stale closure issues when the component unmounts unexpectedly.

2. **SESS-02 confirmed satisfied:** Phase 19 audit verified that useJamServer.js, useSessionStats.js, and useSessionModel.js all have proper timer cleanup patterns. No code changes required.

3. **SESS-03 confirmed satisfied:** Phase 19 audit verified that event listener patterns in useJamServer.js have proper cleanup. No code changes required.

The implementation follows best practices:
- useRef for stable reference across renders
- Both state (for reactivity) and ref (for cleanup) updated on registration
- Cleanup function uses ref to guarantee access to current callbacks
- Multiple exit paths (leave button, navigation, unmount) all trigger cleanup

---

*Verified: 2026-02-08T17:30:00Z*
*Verifier: Claude (gsd-verifier)*
