Prevent sessions from modifying each other's posargs

nox/sessions.py

@@ -506,7 +506,7 @@ def __init__(
         self.global_config = global_config
         self.manifest = manifest
         self.venv: Optional[ProcessEnv] = None
-        self.posargs: List[str] = global_config.posargs
+        self.posargs: List[str] = global_config.posargs[:]
 
     @property
     def description(self) -> Optional[str]:

tests/test__option_set.py

@@ -56,7 +56,7 @@ def test_namespace_non_existant_options_with_values(self):
             optionset.namespace(non_existant_option="meep")
 
     def test_session_completer(self):
-        parsed_args = _options.options.namespace(sessions=(), keywords=())
+        parsed_args = _options.options.namespace(sessions=(), keywords=(), posargs=[])
         all_nox_sessions = _options._session_completer(
             prefix=None, parsed_args=parsed_args
         )
@@ -66,7 +66,9 @@ def test_session_completer(self):
         assert len(set(some_expected_sessions) - set(all_nox_sessions)) == 0
 
     def test_session_completer_invalid_sessions(self):
-        parsed_args = _options.options.namespace(sessions=("baz",), keywords=())
+        parsed_args = _options.options.namespace(
+            sessions=("baz",), keywords=(), posargs=[]
+        )
         all_nox_sessions = _options._session_completer(
             prefix=None, parsed_args=parsed_args
         )

tests/test_manifest.py

@@ -373,7 +373,7 @@ def test_notify_with_posargs():
     # delete my_session from the queue
     manifest.filter_by_name(())
 
-    assert session.posargs is cfg.posargs
+    assert session.posargs == cfg.posargs
     assert manifest.notify("my_session", posargs=["--an-arg"])
     assert session.posargs == ["--an-arg"]
 

tests/test_sessions.py

@@ -67,9 +67,7 @@ def make_session_and_runner(self):
             signatures=["test"],
             func=func,
             global_config=_options.options.namespace(
-                posargs=mock.sentinel.posargs,
-                error_on_external_run=False,
-                install_only=False,
+                posargs=[], error_on_external_run=False, install_only=False
             ),
             manifest=mock.create_autospec(nox.manifest.Manifest),
         )
@@ -101,7 +99,7 @@ def test_properties(self):
 
         assert session.name is runner.friendly_name
         assert session.env is runner.venv.env
-        assert session.posargs is runner.global_config.posargs
+        assert session.posargs == runner.global_config.posargs
         assert session.virtualenv is runner.venv
         assert session.bin_paths is runner.venv.bin_paths
         assert session.bin is runner.venv.bin_paths[0]
@@ -371,7 +369,7 @@ def test_conda_install(self, auto_offline, offline):
             name="test",
             signatures=["test"],
             func=mock.sentinel.func,
-            global_config=_options.options.namespace(posargs=mock.sentinel.posargs),
+            global_config=_options.options.namespace(posargs=[]),
             manifest=mock.create_autospec(nox.manifest.Manifest),
         )
         runner.venv = mock.create_autospec(nox.virtualenv.CondaEnv)
@@ -435,7 +433,7 @@ def test_conda_install_non_default_kwargs(self, version_constraint):
             name="test",
             signatures=["test"],
             func=mock.sentinel.func,
-            global_config=_options.options.namespace(posargs=mock.sentinel.posargs),
+            global_config=_options.options.namespace(posargs=[]),
             manifest=mock.create_autospec(nox.manifest.Manifest),
         )
         runner.venv = mock.create_autospec(nox.virtualenv.CondaEnv)
@@ -492,7 +490,7 @@ def test_install(self):
             name="test",
             signatures=["test"],
             func=mock.sentinel.func,
-            global_config=_options.options.namespace(posargs=mock.sentinel.posargs),
+            global_config=_options.options.namespace(posargs=[]),
             manifest=mock.create_autospec(nox.manifest.Manifest),
         )
         runner.venv = mock.create_autospec(nox.virtualenv.VirtualEnv)
@@ -521,7 +519,7 @@ def test_install_non_default_kwargs(self):
             name="test",
             signatures=["test"],
             func=mock.sentinel.func,
-            global_config=_options.options.namespace(posargs=mock.sentinel.posargs),
+            global_config=_options.options.namespace(posargs=[]),
             manifest=mock.create_autospec(nox.manifest.Manifest),
         )
         runner.venv = mock.create_autospec(nox.virtualenv.VirtualEnv)
@@ -556,6 +554,25 @@ def test_notify(self):
 
         runner.manifest.notify.assert_called_with("other", ["--an-arg"])
 
+    def test_posargs_are_not_shared_between_sessions(self, monkeypatch, tmp_path):
+        registry = {}
+        monkeypatch.setattr("nox.registry._REGISTRY", registry)
+
+        @nox.session(venv_backend="none")
+        def test(session):
+            session.posargs.extend(["-x"])
+
+        @nox.session(venv_backend="none")
+        def lint(session):
+            if "-x" in session.posargs:
+                raise RuntimeError("invalid option: -x")
+
+        config = _options.options.namespace(posargs=[])
+        manifest = nox.manifest.Manifest(registry, config)
+
+        assert manifest["test"].execute()
+        assert manifest["lint"].execute()
+
     def test_log(self, caplog):
         caplog.set_level(logging.INFO)
         session, _ = self.make_session_and_runner()
@@ -628,7 +645,7 @@ def make_runner(self):
             global_config=_options.options.namespace(
                 noxfile=os.path.join(os.getcwd(), "noxfile.py"),
                 envdir="envdir",
-                posargs=mock.sentinel.posargs,
+                posargs=[],
                 reuse_existing_virtualenvs=False,
                 error_on_missing_interpreters=False,
             ),
@@ -644,7 +661,7 @@ def test_properties(self):
         assert runner.func is not None
         assert callable(runner.func)
         assert isinstance(runner.description, str)
-        assert runner.global_config.posargs == mock.sentinel.posargs
+        assert runner.global_config.posargs == []
         assert isinstance(runner.manifest, nox.manifest.Manifest)
 
     def test_str_and_friendly_name(self):

tests/test_tasks.py

@@ -140,7 +140,7 @@ def notasession():
     mock_module = argparse.Namespace(
         __name__=foo.__module__, foo=foo, bar=bar, notasession=notasession
     )
-    config = _options.options.namespace(sessions=(), keywords=())
+    config = _options.options.namespace(sessions=(), keywords=(), posargs=[])
 
     # Get the manifest and establish that it looks like what we expect.
     manifest = tasks.discover_manifest(mock_module, config)
@@ -150,22 +150,28 @@ def notasession():
 
 
 def test_filter_manifest():
-    config = _options.options.namespace(sessions=(), pythons=(), keywords=())
+    config = _options.options.namespace(
+        sessions=(), pythons=(), keywords=(), posargs=[]
+    )
     manifest = Manifest({"foo": session_func, "bar": session_func}, config)
     return_value = tasks.filter_manifest(manifest, config)
     assert return_value is manifest
     assert len(manifest) == 2
 
 
 def test_filter_manifest_not_found():
-    config = _options.options.namespace(sessions=("baz",), pythons=(), keywords=())
+    config = _options.options.namespace(
+        sessions=("baz",), pythons=(), keywords=(), posargs=[]
+    )
     manifest = Manifest({"foo": session_func, "bar": session_func}, config)
     return_value = tasks.filter_manifest(manifest, config)
     assert return_value == 3
 
 
 def test_filter_manifest_pythons():
-    config = _options.options.namespace(sessions=(), pythons=("3.8",), keywords=())
+    config = _options.options.namespace(
+        sessions=(), pythons=("3.8",), keywords=(), posargs=[]
+    )
     manifest = Manifest(
         {"foo": session_func_with_python, "bar": session_func, "baz": session_func},
         config,
@@ -176,7 +182,9 @@ def test_filter_manifest_pythons():
 
 
 def test_filter_manifest_keywords():
-    config = _options.options.namespace(sessions=(), pythons=(), keywords="foo or bar")
+    config = _options.options.namespace(
+        sessions=(), pythons=(), keywords="foo or bar", posargs=[]
+    )
     manifest = Manifest(
         {"foo": session_func, "bar": session_func, "baz": session_func}, config
     )
@@ -231,7 +239,7 @@ def test_verify_manifest_empty():
 
 
 def test_verify_manifest_nonempty():
-    config = _options.options.namespace(sessions=(), keywords=())
+    config = _options.options.namespace(sessions=(), keywords=(), posargs=[])
     manifest = Manifest({"session": session_func}, config)
     return_value = tasks.verify_manifest_nonempty(manifest, global_config=config)
     assert return_value == manifest