beads/tests/integration/AGENT_MAIL_TEST_COVERAGE.md

Agent Mail Integration Test Coverage

Test Suite Summary

Total test time: ~55 seconds (all suites) Total tests: 66 tests across 5 files

Coverage by Category

1. HTTP Adapter Unit Tests (lib/test_beads_mail_adapter.py)

51 tests in 0.019s

✅ Enabled/Disabled Mode

• Server available vs unavailable
• Graceful degradation when server dies mid-operation
• Operations no-op when disabled

✅ Reservation Operations

• Successful reservation (201)
• Conflict handling (409)
• Custom TTL support
• Multiple reservations by same agent
• Release operations (204)
• Double release idempotency

✅ HTTP Error Handling

• 500 Internal Server Error
• 404 Not Found
• 409 Conflict with malformed body
• Network timeouts
• Malformed JSON responses
• Empty response bodies (204 No Content)

✅ Configuration

• Environment variable configuration
• Constructor parameter overrides
• URL normalization (trailing slash removal)
• Default agent name from hostname
• Timeout configuration

✅ Authorization

• Bearer token headers
• Missing token behavior
• Content-Type headers

✅ Request Validation

• Body structure for reservations
• Body structure for notifications
• URL structure for releases
• URL structure for inbox checks

✅ Inbox & Notifications

• Send notifications
• Check inbox with messages
• Empty inbox handling
• Dict wrapper responses
• Large message lists (100 messages)
• Nested payload data
• Empty and large payloads
• Unicode handling

2. Multi-Agent Race Conditions (tests/integration/test_agent_race.py)

3 tests in ~15s

✅ Collision Prevention

• 3 agents competing for 1 issue (WITH Agent Mail)
• Only one winner with reservations
• Multiple agents without Agent Mail (collision demo)

✅ Stress Testing

• 10 agents competing for 1 issue
• Exactly one winner guaranteed
• JSONL consistency verification

3. Server Failure Scenarios (tests/integration/test_mail_failures.py)

7 tests in ~20s

✅ Failure Modes

• Server never started (connection refused)
• Server crash during operation
• Network partition (timeout)
• Server 500 errors
• Invalid bearer token (401)
• Malformed JSON responses

✅ Graceful Degradation

• Agents continue working in Beads-only mode
• JSONL remains consistent across failures
• No crashes or data loss

4. Reservation TTL & Expiration (tests/integration/test_reservation_ttl.py)

4 tests in ~60s (includes 30s waits for expiration)

✅ Time-Based Behavior

• Short TTL reservations (30s)
• Reservation blocking verification
• Auto-release after expiration
• Renewal/heartbeat mechanisms

5. Multi-Agent Coordination (tests/integration/test_multi_agent_coordination.py)

4 tests in ~11s ⭐ NEW

✅ Fairness

• 10 agents competing for 5 issues
• Each issue claimed exactly once
• No duplicate claims in JSONL

✅ Notifications

• End-to-end message delivery
• Inbox consumption (messages cleared after read)
• Message structure validation

✅ Handoff Scenarios

• Agent releases, another immediately claims
• Clean reservation ownership transfer

✅ Idempotency

• Double reserve by same agent (safe)
• Double release by same agent (safe)
• Reservation count verification

Coverage Gaps (Intentionally Not Tested)

Low-Priority Edge Cases

• Path traversal in issue IDs: Issue IDs are validated elsewhere in bd
• 429 Retry-After logic: Nice-to-have, not critical for v1
• HTTPS/TLS verification: Out of scope for integration layer
• Re-enable after recovery: Complex, requires persistent health checking
• Token rotation mid-run: Rare scenario, not worth complexity
• Slow tests: 50+ agent stress tests, soak tests, inbox flood (>10k messages)

Why Skipped

These scenarios are either:

1. Validated elsewhere (e.g., issue ID validation in bd core)
2. Low probability (e.g., token rotation during agent run)
3. Nice-to-have features (e.g., automatic re-enable, retry policies)
4. Too slow for CI (e.g., multi-hour soak tests, 50-agent races)

Test Execution

Run All Tests

# Unit tests (fast, 0.02s)
python3 lib/test_beads_mail_adapter.py

# Multi-agent coordination (11s)
python3 tests/integration/test_multi_agent_coordination.py

# Race conditions (15s, requires Agent Mail server or falls back)
python3 tests/integration/test_agent_race.py

# Failure scenarios (20s)
python3 tests/integration/test_mail_failures.py

# TTL/expiration (60s - includes deliberate waits)
python3 tests/integration/test_reservation_ttl.py

Quick Validation (No Slow Tests)

python3 lib/test_beads_mail_adapter.py
python3 tests/integration/test_multi_agent_coordination.py
python3 tests/integration/test_mail_failures.py
# Total: ~31s

Assertions Verified

✅ Correctness

• Only one agent claims each issue (collision prevention)
• Notifications deliver correctly
• Reservations block other agents
• JSONL remains consistent across all failure modes

✅ Reliability

• Graceful degradation when server unavailable
• Idempotent operations don't corrupt state
• Expired reservations auto-release
• Handoffs work cleanly

✅ Performance

• Fast timeout detection (1-2s)
• No blocking on server failures
• Tests complete in reasonable time (<2min total)

Future Enhancements (Optional)

If real-world usage reveals issues:

1. Retry policies with exponential backoff for 429/5xx
2. Pagination for inbox/reservations (if >1k messages)
3. Automatic re-enable with periodic health checks
4. Agent instance IDs to prevent same-name collisions
5. Soak/stress testing for production validation

Current test suite provides strong confidence for multi-agent workflows without overengineering.