feat: more option argument completions

nox/_options.py

@@ -16,10 +16,18 @@
 
 import argparse
 import functools
+import itertools
 import os
 import sys
+from collections.abc import Iterable
 from typing import Any, Callable, Sequence
 
+from argcomplete.completers import (
+    ChoicesCompleter,
+    DirectoriesCompleter,
+    FilesCompleter,
+)
+
 from nox import _option_set
 from nox.tasks import discover_manifest, filter_manifest, load_nox_module
 
@@ -225,19 +233,43 @@ def _posargs_finalizer(
     return posargs[dash_index + 1 :]
 
 
+def _python_completer(
+    prefix: str, parsed_args: argparse.Namespace, **kwargs: Any
+) -> Iterable[str]:
+    global_config = parsed_args
+    module = load_nox_module(global_config)
+    manifest = discover_manifest(module, global_config)
+    return (
+        session.func.python
+        for session, _ in manifest.list_all_sessions()
+        if session.func.python
+    )
+
+
 def _session_completer(
     prefix: str, parsed_args: argparse.Namespace, **kwargs: Any
-) -> list[str]:
+) -> Iterable[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)
     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]:
+    global_config = parsed_args
+    module = load_nox_module(global_config)
+    manifest = discover_manifest(module, global_config)
+    return itertools.chain.from_iterable(
+        session.tags for session, _ in manifest.list_all_sessions() if session.tags
+    )
 
 
 options.add_options(
@@ -296,6 +328,7 @@ 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",
@@ -305,6 +338,7 @@ def _session_completer(
         noxfile=True,
         merge_func=functools.partial(_sessions_and_keywords_merge_func, "keywords"),
         help="Only run sessions that match the given expression.",
+        completer=ChoicesCompleter(()),
     ),
     _option_set.Option(
         "tags",
@@ -314,6 +348,7 @@ def _session_completer(
         noxfile=True,
         nargs="*",
         help="Only run sessions with the given tags.",
+        completer=_tag_completer,
     ),
     _option_set.Option(
         "posargs",
@@ -418,6 +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=DirectoriesCompleter(),
     ),
     _option_set.Option(
         "extra_pythons",
@@ -427,6 +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",
@@ -440,6 +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",
@@ -491,6 +529,7 @@ def _session_completer(
         group=options.groups["reporting"],
         noxfile=True,
         help="Output a report of all sessions to the given filename.",
+        completer=FilesCompleter(("json",)),
     ),
     _option_set.Option(
         "non_interactive",

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(