---
phase: 02-in-memory-backend-and-owner-security
plan: 02
subsystem: api
tags: [task-context, ergonomic-wrapper, typed-accessors, status-transitions, integration-tests]

requires:
  - phase: 02-in-memory-backend-and-owner-security
    provides: InMemoryTaskStore implementing all 11 TaskStore trait methods
provides:
  - TaskContext ergonomic wrapper for tool handlers (Clone + Send + Sync)
  - Typed variable accessors (get_string, get_i64, get_f64, get_bool, get_typed<T>)
  - Status transition convenience methods (complete, fail, require_input, resume, cancel)
  - TEST-03 integration tests (32 tests across variable CRUD, transitions, identity)
affects: [02-03, 03-handler-integration]

tech-stack:
  added: []
  patterns: [Arc<dyn TaskStore> wrapper, typed accessor returning None on mismatch, atomic complete_with_result delegation]

key-files:
  created:
    - crates/pmcp-tasks/src/context.rs
    - crates/pmcp-tasks/tests/context_tests.rs
  modified:
    - crates/pmcp-tasks/src/lib.rs
    - crates/pmcp-tasks/src/store/memory.rs

key-decisions:
  - "Typed accessors return Ok(None) on type mismatch (not errors) -- consistent with task variable model"
  - "get_typed<T> uses serde_json::from_value with .ok() -- deserialization failures return None, not error"
  - "complete() delegates to store.complete_with_result for atomicity guarantee"
  - "Debug impl uses finish_non_exhaustive to hide store field (not Debug)"

patterns-established:
  - "TaskContext wraps Arc<dyn TaskStore> + task_id + owner_id -- all methods delegate with correct IDs"
  - "Typed accessor pattern: get record, look up key, apply type conversion, return None on mismatch"
  - "Null-deletion via delete_variable sets Value::Null, store removes the key"

requirements-completed: [HNDL-04, HNDL-05, HNDL-06, TEST-03]

duration: 4min
completed: 2026-02-22
---

# Phase 02-02: TaskContext Summary

**TaskContext ergonomic wrapper with typed variable accessors, atomic complete, and 32 integration tests against InMemoryTaskStore**

## Performance

- **Duration:** 4 min
- **Started:** 2026-02-22T01:00:07Z
- **Completed:** 2026-02-22T01:04:17Z
- **Tasks:** 2
- **Files created:** 2, modified: 2

## Accomplishments
- TaskContext (Clone + Send + Sync) wrapping Arc<dyn TaskStore> with ergonomic methods for tool handlers
- Typed variable accessors returning Ok(None) on type mismatch: get_string, get_i64, get_f64, get_bool, get_typed<T>
- Variable mutators with null-deletion semantics: set_variable, set_variables, delete_variable, variables
- Status transition methods delegating to store: complete (atomic via complete_with_result), fail, require_input, resume, cancel
- 32 integration tests in 3 modules covering variable CRUD, status transitions, and TaskContext identity

## Task Commits

1. **Task 1: Implement TaskContext ergonomic wrapper** - `3b0513c` (feat)
2. **Task 2: Write TEST-03 integration tests** - `087d41f` (test)

## Files Created/Modified
- `crates/pmcp-tasks/src/context.rs` - TaskContext struct with all public methods and comprehensive rustdoc
- `crates/pmcp-tasks/tests/context_tests.rs` - 32 integration tests (variable_tests, transition_tests, identity_tests)
- `crates/pmcp-tasks/src/lib.rs` - Added context module declaration and TaskContext re-export
- `crates/pmcp-tasks/src/store/memory.rs` - Fixed pre-existing clippy warning (get().is_none -> !contains_key)

## Decisions Made
- Typed accessors return Ok(None) on type mismatch rather than error -- type mismatches are expected in the task variable model
- get_typed<T> uses serde_json::from_value(...).ok() so deserialization failures silently return None
- complete() delegates to complete_with_result (atomic) rather than separate update_status + set_result
- Debug impl uses finish_non_exhaustive() since Arc<dyn TaskStore> is not Debug

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 1 - Bug] Fixed clippy approx_constant in f64 test**
- **Found during:** Task 2
- **Issue:** Test used 3.14 then 2.718 which clippy flags as approximate math constants
- **Fix:** Changed to 1.234 (not a recognized constant)
- **Files modified:** crates/pmcp-tasks/tests/context_tests.rs
- **Committed in:** 087d41f (Task 2 commit)

**2. [Rule 3 - Blocking] Fixed pre-existing clippy warning in memory.rs**
- **Found during:** Task 2 (clippy --tests)
- **Issue:** `get("key1").is_none()` flagged as unnecessary_get_then_check
- **Fix:** Changed to `!contains_key("key1")`
- **Files modified:** crates/pmcp-tasks/src/store/memory.rs
- **Committed in:** 087d41f (Task 2 commit)

---

**Total deviations:** 2 auto-fixed (1 bug, 1 blocking)
**Impact on plan:** Both fixes necessary for zero-warning clippy compliance. No scope creep.

## Issues Encountered
None.

## User Setup Required
None - no external service configuration required.

## Next Phase Readiness
- TaskContext ready for Phase 3 handler integration (tool handlers receive TaskContext)
- All 32 integration tests pass against InMemoryTaskStore
- Comprehensive tests (02-03) can exercise TaskContext alongside store tests

---
*Phase: 02-in-memory-backend-and-owner-security*
*Completed: 2026-02-22*
