---
phase: 19-audit-and-discovery
plan: 01
subsystem: testing
tags: [memory-leak, audit, react, useEffect, redux, cleanup]

# Dependency graph
requires:
  - phase: 18-session-settings-tests
    provides: Testing methodology and verification patterns
provides:
  - Comprehensive memory leak audit of session screen components
  - Priority-ranked findings (VUMTR-01/02/03, CHAT-01/02/03, SESS-01)
  - Implementation recommendations for Phases 20-22
affects: [20-vu-meter-fixes, 21-chat-fixes, 22-session-hardening]

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "Audit methodology: static analysis with line-by-line verification"
    - "Finding format: ID, description, file, lines, severity, recommendation"

key-files:
  created:
    - .planning/phases/19-audit-and-discovery/19-AUDIT.md
  modified: []

key-decisions:
  - "VU meter vuStates unbounded growth is HIGH priority (VUMTR-02, VUMTR-03)"
  - "Chat messages unbounded growth is HIGH priority (CHAT-01)"
  - "Session screen base components have proper cleanup - not primary leak sources"

patterns-established:
  - "Severity rating: HIGH = likely freeze cause, MEDIUM = degradation, LOW = minor"
  - "Finding ID format: {AREA}-{NUMBER} (VUMTR-01, CHAT-01, SESS-01)"

# Metrics
duration: 25min
completed: 2026-02-08
---

# Phase 19 Plan 01: Memory Leak Audit Summary

**Comprehensive audit of session screen identifying vuStates unbounded growth (HIGH), chat message accumulation (HIGH), and proper cleanup in base session components**

## Performance

- **Duration:** 25 min
- **Started:** 2026-02-08
- **Completed:** 2026-02-08
- **Tasks:** 3
- **Files modified:** 1

## Accomplishments

- Audited VU meter components (SessionTrackVU, useMixerStore, useVuHelpers) - found 3 issues
- Audited chat window components (JKSessionChatWindow, sessionChatSlice, useSessionWebSocket) - found 3 issues
- Audited session screen and supporting hooks (JKSessionScreen, useJamServer, useSessionStats, useSessionModel) - confirmed proper cleanup
- Created prioritized implementation recommendations for Phases 20-22

## Task Commits

Each task was committed atomically:

1. **Task 1: Audit VU Meter Components** - `1c898ddc0` (audit)
2. **Task 2: Audit Chat Window Components** - `e9ff93d3d` (audit)
3. **Task 3: Audit Session Screen and Finalize Report** - `4d0175f18` (audit)

## Files Created/Modified

- `.planning/phases/19-audit-and-discovery/19-AUDIT.md` - Comprehensive memory leak audit report

## Decisions Made

1. **Severity classification:** HIGH for unbounded state growth patterns that accumulate over time, MEDIUM for performance issues, LOW for edge cases with proper workarounds

2. **Primary leak sources identified:**
   - VUMTR-02/03: vuStates object in useVuHelpers.js grows unbounded
   - CHAT-01: messagesByChannel in sessionChatSlice.js has no limit

3. **Session screen cleared:** Base session screen components (JKSessionScreen.js, useJamServer.js, player components) have well-implemented cleanup patterns and are NOT primary leak sources

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered

None - static code analysis proceeded smoothly across all files.

## User Setup Required

None - no external service configuration required.

## Key Findings Summary

### HIGH Severity (Primary Fix Targets)

| ID | Finding | Location |
|----|---------|----------|
| VUMTR-02 | vuStates object grows unbounded | useVuHelpers.js lines 6, 99-104 |
| VUMTR-03 | No per-mixer cleanup on track leave | useVuHelpers.js lines 117-122 |
| CHAT-01 | Messages accumulate without limit | sessionChatSlice.js lines 202, 366, 512 |

### MEDIUM Severity

| ID | Finding | Location |
|----|---------|----------|
| VUMTR-01 | VU callback throttling disabled | useMixerStore.js lines 141-152 |
| CHAT-03 | No message cleanup on session leave | sessionChatSlice.js N/A |

### LOW Severity

| ID | Finding | Location |
|----|---------|----------|
| CHAT-02 | chatState in useEffect dependencies | useSessionWebSocket.js line 308 |
| SESS-01 | Callback unregistration relies on leave handler | JKSessionScreen.js lines 616-629 |

## Next Phase Readiness

**Ready for Phase 20 (VU Meter Fixes):**
- VUMTR-02 and VUMTR-03 clearly documented with line numbers
- Fix recommendation: Add removeVuState function, integrate with track lifecycle

**Ready for Phase 21 (Chat Fixes):**
- CHAT-01 clearly documented with line numbers
- Fix recommendation: Add MAX_MESSAGES constant (500), apply slice() in reducers

**Ready for Phase 22 (Session Hardening):**
- SESS-01 documented as defensive improvement
- Fix recommendation: Add backup cleanup in useEffect return

**Estimated total fix effort:** 2-3 hours for Phases 20-21, 1 hour for Phase 22

---
*Phase: 19-audit-and-discovery*
*Completed: 2026-02-08*
