---
phase: 11-dynamodb-backend
plan: 02
subsystem: database
tags: [dynamodb, aws-sdk, storage-backend, integration-tests, feature-flag, contract-tests]

# Dependency graph
requires:
  - phase: 11-dynamodb-backend
    provides: DynamoDbBackend struct implementing StorageBackend with all 6 methods
  - phase: 10-inmemory-backend-refactor
    provides: Per-backend contract test pattern in memory.rs::backend_tests
provides:
  - 18 integration tests for DynamoDbBackend covering all 6 StorageBackend methods
  - Test-only client() and table_name() accessors for raw DynamoDB inspection
  - TTL attribute verification tests (expires_at presence/absence)
  - dynamodb-tests feature flag gating for CI-safe test execution
affects: [phase-12 redis backend test pattern reference]

# Tech tracking
tech-stack:
  added: []
  patterns: [feature-gated integration tests behind dynamodb-tests, UUID-based test isolation per test run, raw DynamoDB GetItem for TTL attribute verification]

key-files:
  created: []
  modified:
    - crates/pmcp-tasks/src/store/dynamodb.rs

key-decisions:
  - "put_if_version on missing key returns VersionConflict (not NotFound) because DynamoDB ConditionExpression fails the same way for both cases"
  - "TTL tests inspect raw DynamoDB items via client().get_item() rather than waiting for actual TTL deletion (up to 48h)"
  - "Each test uses unique UUID owner prefix for isolation -- no cleanup needed, tests never collide"

patterns-established:
  - "DynamoDB integration test pattern: test_backend() helper returns (DynamoDbBackend, unique_prefix)"
  - "Feature-gated tests: #[cfg(all(test, feature = \"dynamodb-tests\"))] mod integration_tests"
  - "Test-only struct accessors: #[cfg(test)] pub(crate) fn client/table_name for raw inspection"
  - "ddb_ test name prefix to distinguish DynamoDB tests from in-memory contract tests"

requirements-completed: [DYNA-06, TEST-02]

# Metrics
duration: 5min
completed: 2026-02-24
---

# Phase 11 Plan 02: DynamoDB Integration Tests Summary

**18 StorageBackend contract tests for DynamoDbBackend covering get/put/CAS/delete/list/cleanup/TTL, gated behind dynamodb-tests feature flag with UUID-based test isolation**

## Performance

- **Duration:** 5 min
- **Started:** 2026-02-24T04:01:20Z
- **Completed:** 2026-02-24T04:06:44Z
- **Tasks:** 2
- **Files modified:** 1

## Accomplishments
- 18 integration tests mirroring the InMemoryBackend contract test pattern from Phase 10
- Tests cover all 6 StorageBackend methods: get (2), put (3), put_if_version (4), delete (3), list_by_prefix (3), cleanup_expired (1), TTL verification (2)
- Test-only `client()` and `table_name()` accessors on DynamoDbBackend for raw DynamoDB item inspection
- All 561 existing tests pass with zero regressions, zero clippy warnings, clean formatting

## Task Commits

Each task was committed atomically:

1. **Task 1: DynamoDB integration test module with all StorageBackend contract tests** - `eafdff4` (test)
2. **Task 2: Cleanup test helper access and final verification** - `efab375` (chore)

## Files Created/Modified
- `crates/pmcp-tasks/src/store/dynamodb.rs` - Added test-only accessors (client, table_name) and integration_tests module with 18 tests (378 lines added)

## Decisions Made
- **put_if_version on missing key behavior:** DynamoDB's ConditionExpression fails with ConditionalCheckFailedException for both version mismatch and missing items, so the test asserts VersionConflict (not NotFound) for put_if_version on nonexistent keys. This differs from InMemoryBackend which returns NotFound, but both are valid per the trait contract.
- **TTL verification approach:** Tests inspect raw DynamoDB items via `backend.client().get_item()` to verify `expires_at` attribute presence and correctness, rather than waiting for DynamoDB's actual TTL deletion (which takes up to 48 hours).
- **UUID-based test isolation:** Each test gets a unique owner prefix (`test-{uuid}`) so tests never interfere with each other and no post-test cleanup is needed.

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 1 - Bug] Fixed formatting violations in integration tests**
- **Found during:** Task 2 (quality gate verification)
- **Issue:** `cargo fmt --check` flagged several method chains and match arms that could be collapsed to single lines
- **Fix:** Ran `cargo fmt -p pmcp-tasks` to auto-format
- **Files modified:** crates/pmcp-tasks/src/store/dynamodb.rs
- **Verification:** `cargo fmt -p pmcp-tasks --check` passes
- **Committed in:** efab375 (Task 2 commit)

---

**Total deviations:** 1 auto-fixed (1 formatting)
**Impact on plan:** Trivial formatting adjustment. No scope creep.

## Issues Encountered
- Pre-existing doc warnings in `workflow.rs` and `router.rs` (references to `SequentialWorkflow`, `WorkflowStep`, `WorkflowProgress` items not in scope). These are not caused by this plan's changes and are out of scope.

## User Setup Required
**External services require manual configuration for running integration tests.** AWS credentials and a DynamoDB table are required:
- Environment variables: `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`, `AWS_DEFAULT_REGION`
- DynamoDB table: `pmcp_tasks` with PK (String) + SK (String) partition/sort keys, on-demand capacity mode
- TTL: Enable on `expires_at` attribute via Table -> Additional settings -> Time to live
- Run: `cargo test -p pmcp-tasks --features dynamodb-tests -- ddb_ --test-threads=1`

## Next Phase Readiness
- DynamoDbBackend is complete with full StorageBackend implementation and 18 integration tests
- Phase 11 (DynamoDB Backend) is fully complete
- Ready for Phase 12: Redis backend implementation (can follow same feature-gated pattern)

## Self-Check: PASSED

- [x] crates/pmcp-tasks/src/store/dynamodb.rs exists with integration_tests module
- [x] 18 test functions with `ddb_` prefix
- [x] Commit eafdff4 exists in git log
- [x] Commit efab375 exists in git log
- [x] .planning/phases/11-dynamodb-backend/11-02-SUMMARY.md exists

---
*Phase: 11-dynamodb-backend*
*Completed: 2026-02-24*
