Job methods docstrings (#1772)

* Improve docstrings on `connections`

* Enhanced Job methods docstrings & Serialization Protocol

This adds docstrings to all Job methods in a standard format.
It also implements a `serializer` protocol.

* Excludes `Protocol` (keeping compatibility with < 3.8)

* Add docstrings & type annotation to the `job` decorator

* Docstrings for the `defaults` vars

* Add deprecation warning to Connection context manager

* Fix Types

1 files changed, 17 insertions, 0 deletions

diff --git a/rq/types.py b/rq/types.py
new file mode 100644
index 0000000..fe8e002
--- /dev/null
+++ b/rq/types.py
@@ -0,0 +1,17 @@
+from typing import TYPE_CHECKING, Any, Callable, List, TypeVar, Union
+
+if TYPE_CHECKING:
+    from .job import Dependency, Job
+
+
+FunctionReferenceType = TypeVar('FunctionReferenceType', str, Callable[..., Any])
+"""Custom type definition for what a `func` is in the context of a job.
+A `func` can be a string with the function import path (eg.: `myfile.mymodule.myfunc`)
+or a direct callable (function/method).
+"""
+
+
+JobDependencyType = TypeVar('JobDependencyType', 'Dependency', 'Job', str, List[Union['Dependency', 'Job']])
+"""Custom type definition for a job dependencies.
+A simple helper definition for the `depends_on` parameter when creating a job.
+"""