Add some typing and py.typed

This also discovered the missing definition of an abstract base
broadcast_status from the CommonTransport class.

Author: ndevenish

MANIFEST.in

@@ -10,3 +10,4 @@ recursive-exclude * *.py[co]
 
 recursive-include docs *.rst conf.py Makefile make.bat *.jpg *.png *.gif
 
+include src/workflows/py.typed

setup.cfg

@@ -35,6 +35,7 @@ package_dir =
     =src
 python_requires = >=3.7
 zip_safe = False
+include_package_data = True
 
 [options.extras_require]
 prometheus = prometheus-client

src/workflows/__init__.py

@@ -3,7 +3,7 @@
 __version__ = "2.24.1"
 
 
-def version():
+def version() -> str:
     """Returns the version number of the installed workflows package."""
     return __version__
 

src/workflows/py.typed

@@ -2,22 +2,25 @@
 
 import argparse
 import optparse
-from typing import Union
+from typing import TYPE_CHECKING, Type
 
 import pkg_resources
 
+if TYPE_CHECKING:
+    from .common_transport import CommonTransport
+
 default_transport = "PikaTransport"
 
 
-def lookup(transport):
+def lookup(transport: str) -> Type[CommonTransport]:
     """Get a transport layer class based on its name."""
     return get_known_transports().get(
         transport, get_known_transports()[default_transport]
     )
 
 
 def add_command_line_options(
-    parser: Union[argparse.ArgumentParser, optparse.OptionParser],
+    parser: argparse.ArgumentParser | optparse.OptionParser,
     transport_argument: bool = False,
 ) -> None:
     """Add command line options for all available transport layer classes."""
@@ -52,7 +55,7 @@ def add_command_line_options(
         transport().add_command_line_options(parser)
 
 
-def get_known_transports():
+def get_known_transports() -> dict[str, Type[CommonTransport]]:
     """Return a dictionary of all known transport mechanisms."""
     if not hasattr(get_known_transports, "cache"):
         setattr(
@@ -63,4 +66,4 @@ def get_known_transports():
                 for e in pkg_resources.iter_entry_points("workflows.transport")
             },
         )
-    return get_known_transports.cache.copy()
+    return get_known_transports.cache.copy()  # type: ignore

src/workflows/transport/__init__.py

@@ -315,6 +315,10 @@ def raw_broadcast(self, destination, message, **kwargs):
 
         self._broadcast(destination, message, **kwargs)
 
+    def broadcast_status(self, status: dict) -> None:
+        """Broadcast transient status information to all listeners"""
+        raise NotImplementedError
+
     @middleware.wrap
     def ack(self, message, subscription_id: Optional[int] = None, **kwargs):
         """Acknowledge receipt of a message. This only makes sense when the