feat: more option argument completions

nox/_option_set.py

@@ -23,7 +23,7 @@
 import functools
 from argparse import ArgumentError as ArgumentError
 from argparse import ArgumentParser, Namespace
-from collections.abc import Callable, Sequence
+from collections.abc import Callable, Iterable
 from typing import Any
 
 import argcomplete
@@ -92,7 +92,7 @@ def __init__(
         | list[str]
         | Callable[[], bool | str | None | list[str]] = None,
         hidden: bool = False,
-        completer: Callable[..., Sequence[str]] | None = None,
+        completer: Callable[..., Iterable[str]] | None = None,
         **kwargs: Any,
     ) -> None:
         self.name = name

nox/_options.py

@@ -16,10 +16,14 @@
 
 import argparse
 import functools
+import itertools
 import os
 import sys
+from collections.abc import Iterable
 from typing import Any, Callable, Sequence
 
+import argcomplete
+
 from nox import _option_set
 from nox.tasks import discover_manifest, filter_manifest, load_nox_module
 
@@ -229,19 +233,42 @@ def _posargs_finalizer(
     return posargs[dash_index + 1 :]
 
 
+def _python_completer(
+    prefix: str, parsed_args: argparse.Namespace, **kwargs: Any
+) -> Iterable[str]:
+    module = load_nox_module(parsed_args)
+    manifest = discover_manifest(module, parsed_args)
+    return filter(
+        None,
+        (
+            session.func.python  # type:ignore[misc] # str sequences flattened, other non-strs falsey and filtered out
+            for session, _ in manifest.list_all_sessions()
+        ),
+    )
+
+
 def _session_completer(
     prefix: str, parsed_args: argparse.Namespace, **kwargs: Any
-) -> list[str]:
-    global_config = parsed_args
-    global_config.list_sessions = True
-    module = load_nox_module(global_config)
-    manifest = discover_manifest(module, global_config)
-    filtered_manifest = filter_manifest(manifest, global_config)
+) -> Iterable[str]:
+    parsed_args.list_sessions = True
+    module = load_nox_module(parsed_args)
+    manifest = discover_manifest(module, parsed_args)
+    filtered_manifest = filter_manifest(manifest, parsed_args)
     if isinstance(filtered_manifest, int):
         return []
-    return [
+    return (
         session.friendly_name for session, _ in filtered_manifest.list_all_sessions()
-    ]
+    )
+
+
+def _tag_completer(
+    prefix: str, parsed_args: argparse.Namespace, **kwargs: Any
+) -> Iterable[str]:
+    module = load_nox_module(parsed_args)
+    manifest = discover_manifest(module, parsed_args)
+    return itertools.chain.from_iterable(
+        filter(None, (session.tags for session, _ in manifest.list_all_sessions()))
+    )
 
 
 options.add_options(
@@ -300,6 +327,7 @@ def _session_completer(
         nargs="*",
         default=default_env_var_list_factory("NOXPYTHON"),
         help="Only run sessions that use the given python interpreter versions.",
+        completer=_python_completer,
     ),
     _option_set.Option(
         "keywords",
@@ -309,6 +337,7 @@ def _session_completer(
         noxfile=True,
         merge_func=functools.partial(_sessions_merge_func, "keywords"),
         help="Only run sessions that match the given expression.",
+        completer=argcomplete.completers.ChoicesCompleter(()),
     ),
     _option_set.Option(
         "tags",
@@ -319,6 +348,7 @@ def _session_completer(
         merge_func=functools.partial(_sessions_merge_func, "tags"),
         nargs="*",
         help="Only run sessions with the given tags.",
+        completer=_tag_completer,
     ),
     _option_set.Option(
         "posargs",
@@ -423,6 +453,7 @@ def _session_completer(
         merge_func=_envdir_merge_func,
         group=options.groups["environment"],
         help="Directory where Nox will store virtualenvs, this is ``.nox`` by default.",
+        completer=argcomplete.completers.DirectoriesCompleter(),
     ),
     _option_set.Option(
         "extra_pythons",
@@ -432,6 +463,7 @@ def _session_completer(
         nargs="*",
         default=default_env_var_list_factory("NOXEXTRAPYTHON"),
         help="Additionally, run sessions using the given python interpreter versions.",
+        completer=_python_completer,
     ),
     _option_set.Option(
         "force_pythons",
@@ -445,6 +477,7 @@ def _session_completer(
             " Noxfile. This is a shorthand for ``--python=X.Y --extra-python=X.Y``."
         ),
         finalizer_func=_force_pythons_finalizer,
+        completer=_python_completer,
     ),
     *_option_set.make_flag_pair(
         "stop_on_first_error",
@@ -496,6 +529,7 @@ def _session_completer(
         group=options.groups["reporting"],
         noxfile=True,
         help="Output a report of all sessions to the given filename.",
+        completer=argcomplete.completers.FilesCompleter(("json",)),
     ),
     _option_set.Option(
         "non_interactive",

tests/resources/noxfile_pythons.py

@@ -7,3 +7,13 @@
 @nox.parametrize("cheese", ["cheddar", "jack", "brie"])
 def snack(unused_session, cheese):
     print(f"Noms, {cheese} so good!")
+
+
+@nox.session(python=False)
+def nopy(unused_session):
+    print("No pythons here.")
+
+
+@nox.session(python="3.12")
+def strpy(unused_session):
+    print("Python-in-a-str here.")

tests/resources/noxfile_tags.py

@@ -0,0 +1,18 @@
+from __future__ import annotations
+
+import nox
+
+
+@nox.session  # no tags
+def no_tags(unused_session):
+    print("Look ma, no tags!")
+
+
+@nox.session(tags=["tag1"])
+def one_tag(unused_session):
+    print("Lonesome tag here.")
+
+
+@nox.session(tags=["tag1", "tag2", "tag3"])
+def moar_tags(unused_session):
+    print("Some more tags here.")

tests/test__option_set.py

@@ -95,7 +95,7 @@ def test_session_completer(self):
         )
 
         expected_sessions = ["testytest", "lintylint", "typeytype"]
-        assert expected_sessions == actual_sessions_from_file
+        assert expected_sessions == list(actual_sessions_from_file)
 
     def test_session_completer_invalid_sessions(self):
         parsed_args = _options.options.namespace(
@@ -105,3 +105,27 @@ def test_session_completer_invalid_sessions(self):
             prefix=None, parsed_args=parsed_args
         )
         assert len(all_nox_sessions) == 0
+
+    def test_python_completer(self):
+        parsed_args = _options.options.namespace(
+            posargs=[],
+            noxfile=str(RESOURCES.joinpath("noxfile_pythons.py")),
+        )
+        actual_pythons_from_file = _options._python_completer(
+            prefix=None, parsed_args=parsed_args
+        )
+
+        expected_pythons = {"3.6", "3.12"}
+        assert expected_pythons == set(actual_pythons_from_file)
+
+    def test_tag_completer(self):
+        parsed_args = _options.options.namespace(
+            posargs=[],
+            noxfile=str(RESOURCES.joinpath("noxfile_tags.py")),
+        )
+        actual_tags_from_file = _options._tag_completer(
+            prefix=None, parsed_args=parsed_args
+        )
+
+        expected_tags = {"tag1", "tag2", "tag3"}
+        assert expected_tags == set(actual_tags_from_file)