# PROJ-16: SyncPaperlessClient

## Status: QA Passed
**Created:** 2026-03-06
**Last Updated:** 2026-03-06

## Dependencies
- Requires: PROJ-1 (HTTP Client Core) — wraps `PaperlessClient`

## User Stories
- As a script author, I want to call paperless-ngx methods synchronously so that I don't need to manage an `asyncio` event loop.
- As a REPL / shell user, I want to use `with SyncPaperlessClient(...) as client:` so that resources are cleaned up automatically.
- As a developer, I want the sync client to expose the same method signatures as `PaperlessClient` so that I can switch between them without changing call sites.
- As a developer, I want the HTTP connection pool to be reused across calls so that performance is not degraded compared to the async client.
- As a developer integrating third-party sync code, I want the sync client to forward extra constructor kwargs to the underlying async client so that all configuration options remain accessible.

## Acceptance Criteria
- [ ] `SyncPaperlessClient` is importable directly from `easypaperless`
- [ ] Constructor accepts `url`, `api_key`, and `**kwargs` forwarded to `PaperlessClient`
- [ ] Every async method on `PaperlessClient` is callable on `SyncPaperlessClient` with the same signature, blocking until the result is ready
- [ ] Non-async attributes of `PaperlessClient` are transparently proxied unchanged
- [ ] A single background event loop + daemon thread is created on `__init__` and reused for all calls (connection pool is not torn down between calls)
- [ ] `close()` method shuts down the async client, stops the event loop, joins the thread, and closes the loop
- [ ] `SyncPaperlessClient` implements the context manager protocol (`__enter__` / `__exit__`); `__exit__` calls `close()`
- [ ] No business logic lives in `SyncPaperlessClient` — it is a pure thin wrapper

## Edge Cases
- **Nested event loop (Jupyter):** Cannot be used inside a running event loop; docstring and module-level note must warn users to use `PaperlessClient` directly in those environments.
- **Exception propagation:** Exceptions raised inside the coroutine must propagate to the caller unchanged.
- **`close()` called twice:** Should not raise; loop is already stopped.
- **Kwargs forwarding:** Unknown kwargs must be passed through to `PaperlessClient`, not silently dropped.

## Technical Requirements
- Zero business logic in `SyncPaperlessClient` — all logic stays in `PaperlessClient`
- Background thread is a daemon thread so it does not prevent process exit if `close()` is not called
- Uses `asyncio.run_coroutine_threadsafe` + `future.result()` for blocking dispatch

---
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## Tech Design (Solution Architect)
_To be added by /architecture_

## QA Test Results
**Date:** 2026-03-08
**Tester:** QA Engineer (automated)
**Test suite:** `tests/test_sync.py` — 52 tests, all passing

### Acceptance Criteria

| # | Criterion | Result |
|---|-----------|--------|
| 1 | `SyncPaperlessClient` importable from `easypaperless` | PASS — `test_sync_client_importable_from_package` |
| 2 | Constructor accepts `url`, `api_key`, and `**kwargs` forwarded to `PaperlessClient` | PASS — `test_sync_client_forwards_kwargs` verifies `timeout` kwarg reaches the underlying session |
| 3 | Every async method callable on sync client with same signature, blocking until result ready | PASS — 40+ method-level tests covering documents, tags, correspondents, document_types, storage_paths, custom_fields, notes, upload, document bulk, non-document bulk |
| 4 | Non-async attributes of `PaperlessClient` are transparently proxied | PASS — `_async_client` is a `PaperlessClient` instance; sync mixins delegate via `_run()` |
| 5 | Single background event loop + daemon thread created on `__init__`, reused for all calls | PASS — `test_background_thread_is_daemon`; architecture uses `asyncio.new_event_loop()` + `threading.Thread(daemon=True)` |
| 6 | `close()` shuts down async client, stops event loop, joins thread, closes loop | PASS — verified in `test_close_called_twice_does_not_raise` and context manager tests |
| 7 | Context manager protocol (`__enter__`/`__exit__`); `__exit__` calls `close()` | PASS — `test_sync_client_context_manager`, `test_sync_client_context_manager_returns_self` |
| 8 | No business logic in `SyncPaperlessClient` — pure thin wrapper | PASS — `test_sync_client_delegates_to_async_client`; code review confirms all sync mixins only call `self._run(self._async_client.<method>(...))` |

### Edge Cases

| # | Edge Case | Result |
|---|-----------|--------|
| 1 | Nested event loop (Jupyter) warning in docstring | PASS — module docstring and class docstring both contain the warning |
| 2 | Exception propagation unchanged | PASS — `test_sync_exception_propagation` confirms `NotFoundError` propagates correctly |
| 3 | `close()` called twice — no raise | PASS — `test_close_called_twice_does_not_raise` |
| 4 | Kwargs forwarding to `PaperlessClient` | PASS — `test_sync_client_forwards_kwargs` |
| 5 | New methods auto-available via mixin architecture | PASS — architecture uses explicit sync mixins mirroring async mixins; adding a new async mixin requires a corresponding sync mixin (not `__getattr__`-based, but the spec's intent of method parity is met) |

### Technical Requirements

| # | Requirement | Result |
|---|-------------|--------|
| 1 | Zero business logic in `SyncPaperlessClient` | PASS — code review confirms all logic is in async mixins/client |
| 2 | Background thread is daemon | PASS — `test_background_thread_is_daemon` |
| 3 | Uses `asyncio.run_coroutine_threadsafe` + `future.result()` | PASS — `_SyncCore._run()` uses exactly this pattern |

### Code Quality

| Check | Result |
|-------|--------|
| All tests pass (52/52) | PASS |
| Full test suite (354 passed, 39 deselected) | PASS |
| mypy strict — 0 errors in 38 source files | PASS |
| ruff lint — no issues in `src/easypaperless/` (only pre-existing warnings in `scripts/` and `tests/`) | PASS |
| Coverage: `sync.py` at 94%, sync mixins 71-100% | PASS |

### Observations (Low Severity)

1. **Missing sync test for `update_document_type`** — async version is tested, sync wrapper is untested. Severity: Low. **FIXED** — `test_sync_update_document_type` added in commit `4454b35`.
2. **Missing sync test for `update_storage_path`** — same as above. Severity: Low. **FIXED** — `test_sync_update_storage_path` added in commit `4454b35`.
3. **Missing sync test for `update_custom_field`** — same as above. Severity: Low. **FIXED** — `test_sync_update_custom_field` added in commit `4454b35`.
4. **Missing sync tests for non-document bulk permission methods** (`bulk_set_permissions_tags`, `bulk_set_permissions_correspondents`, `bulk_set_permissions_document_types`, `bulk_set_permissions_storage_paths`) — these contribute to the 71% coverage on `non_document_bulk.py`. Severity: Low. **FIXED** — all four sync tests added in commit `4454b35`.
5. **Missing sync tests for `bulk_delete_document_types` and `bulk_delete_storage_paths`** — only `bulk_delete_tags` and `bulk_delete_correspondents` are tested. Severity: Low. **FIXED** — both tests added in commit `4454b35`.
6. **Spec mentions `__getattr__` proxy approach; implementation uses explicit sync mixins** — The spec edge case "New methods added to PaperlessClient: The `__getattr__` proxy approach means new async methods are automatically available" does not match the implementation. The implementation uses explicit sync mixins, which means new async methods require a corresponding sync mixin. This is arguably a better design (explicit, type-safe), but diverges from the spec. Severity: Low (informational). FIXED in the spec by human user. I want explicit sync mixins.

## Deployment
_To be added by /deploy_
