Expose execnet.Gateway and execnet.Channel for typing purposes

These two types prominently appear in the public API so let's allow to
refer to them.

The constructors are considered private.

Author: bluetech

CHANGELOG.rst

@@ -14,6 +14,8 @@
 
   Also fixed ``init_popen_io`` to use ``closefd=False`` for shared stdin and stdout file
   descriptors, preventing ``Bad file descriptor`` errors triggered by test_stdouterrin_setnull.
+* Re-exported ``Gateway`` and ``Channel`` from ``execnet``. The constructors
+  are private.
 * Fixed ``GatewayBase.join()`` timeout argument getting ignored.
 * Removed support for Python 3.7.
 * Added official support for Python 3.12.

src/execnet/__init__.py

@@ -8,6 +8,8 @@
 """
 
 from ._version import version as __version__
+from .gateway import Gateway
+from .gateway_base import Channel
 from .gateway_base import DataFormatError
 from .gateway_base import RemoteError
 from .gateway_base import TimeoutError
@@ -32,10 +34,12 @@
     "RemoteError",
     "TimeoutError",
     "XSpec",
+    "Gateway",
     "Group",
     "MultiChannel",
     "RSync",
     "default_group",
+    "Channel",
     "dumps",
     "loads",
     "load",

src/execnet/gateway.py

@@ -27,6 +27,7 @@ class Gateway(gateway_base.BaseGateway):
     _group: Group
 
     def __init__(self, io: IO, spec: XSpec) -> None:
+        """:private:"""
         super().__init__(io=io, id=spec.id, _startcount=1)
         self.spec = spec
         self._initreceive()

src/execnet/gateway_base.py

@@ -708,6 +708,7 @@ class Channel:
     _executing = False
 
     def __init__(self, gateway: BaseGateway, id: int) -> None:
+        """:private:"""
         assert isinstance(id, int)
         assert not isinstance(gateway, type)
         self.gateway = gateway

src/execnet/gateway_bootstrap.py

@@ -8,7 +8,6 @@
 import execnet
 
 from . import gateway_base
-from .gateway import Gateway
 from .gateway_base import IO
 from .xspec import XSpec
 
@@ -81,7 +80,7 @@ def sendexec(io: IO, *sources: str) -> None:
     io.write((repr(source) + "\n").encode("utf-8"))
 
 
-def bootstrap(io: IO, spec: XSpec) -> Gateway:
+def bootstrap(io: IO, spec: XSpec) -> execnet.Gateway:
     if spec.popen:
         if spec.via or spec.python:
             bootstrap_exec(io, spec)
@@ -93,5 +92,5 @@ def bootstrap(io: IO, spec: XSpec) -> Gateway:
         bootstrap_socket(io, spec)
     else:
         raise ValueError("unknown gateway type, can't bootstrap")
-    gw = Gateway(io, spec)
+    gw = execnet.Gateway(io, spec)
     return gw