Expand contributing guide

CONTRIBUTING.md

@@ -1,21 +1,45 @@
 # Contributing
 
+This guide covers the local development workflow for `labapi`: setting up the
+project, running tests, enforcing code style, and following the project's type
+system conventions.
+
 ## Setup
 
+Install the package and its development dependencies with `uv`, then install
+both hook types:
+
 ```bash
 uv sync --all-groups
 pre-commit install --hook-type pre-commit --hook-type pre-push
 ```
 
 ## Running Tests
 
-Unit tests run entirely offline using `MockClient`:
+The test suite is split into unit tests and integration tests. Plain `pytest`
+deselects integration tests by default.
+
+Run the full suite, including integration tests, with:
+
+```bash
+uv run pytest --integration
+```
+
+### Unit Tests
+
+Unit tests use `MockClient` to replay pre-recorded API responses, so they run
+entirely offline:
 
 ```bash
 uv run pytest
+uv run pytest --no-cov
+uv run pytest tests/tree/test_mixins.py
 ```
 
-Integration tests are opt-in and require live API credentials in `.env` or the environment:
+### Integration Tests
+
+Integration tests are opt-in and require live API credentials in `.env` or the
+environment:
 
 ```bash
 # Required
@@ -35,11 +59,14 @@ AUTH_KEY=your_auth_key
 uv run pytest --integration tests/test_integration.py
 ```
 
-`Client()` only auto-loads `API_URL`, `ACCESS_KEYID`, and `ACCESS_PWD`; `AUTH_EMAIL` and `AUTH_KEY` are test-fixture conventions used by the integration suite.
+`Client()` only auto-loads `API_URL`, `ACCESS_KEYID`, and `ACCESS_PWD`;
+`AUTH_EMAIL` and `AUTH_KEY` are test-fixture conventions used by the integration
+suite.
 
 ## Code Style
 
-Ruff handles linting, formatting, and branch-complexity checks. Pyright handles type checking. After installing both hook types:
+Ruff handles linting, formatting, and branch-complexity checks. Pyright handles
+type checking. After installing both hook types:
 
 - `ruff-check`, `ruff-format`, and `pyright-check` run on `pre-commit`
 - `pytest-check` runs `uv run pytest --no-cov` on `pre-push`
@@ -54,7 +81,28 @@ uv run radon cc src tests -s -a  # complexity report
 uv run pytest --no-cov      # pre-push test gate
 ```
 
-## Type Annotations
+To check formatting and linting without changing files:
+
+```bash
+uv run ruff check .
+uv run ruff format --check .
+```
+
+## Continuous Integration
+
+GitHub Actions run the project's main quality gates in separate workflows:
+
+- unit tests
+- lint
+- formatting
+- type checking
+- documentation builds
+- manually triggered integration tests
+
+Run the corresponding commands locally before pushing to catch failures before
+CI.
+
+## Type System
 
 Run type checking locally with:
 
@@ -64,7 +112,13 @@ uv run pyright
 
 All new code must be fully type-annotated. Key conventions:
 
-- `from __future__ import annotations` in every module
+- `from __future__ import annotations` in modules that rely on forward references
 - `override` on all method overrides
 - `TYPE_CHECKING` guards to avoid circular imports
 - Generics where they give callers concrete return types (e.g. `Entry[Attachment]`)
+- `overload` on APIs such as `__getitem__` that return different types for
+  different index kinds
+
+The project targets Python 3.10 and newer. Keep source syntax compatible with
+Python 3.10, using `typing_extensions` where needed. For example, use
+`TypeVar` and `Generic` rather than PEP 695 generic parameter syntax.