Add deprecations for tests written for nose (pytest-dev#9907)

Fixes pytest-dev#9886

Author: symonk

.gitignore

@@ -50,6 +50,7 @@ coverage.xml
 .project
 .settings
 .vscode
+__pycache__/
 
 # generated by pip
 pip-wheel-metadata/

changelog/9886.deprecation.rst

@@ -0,0 +1,10 @@
+The functionality for running tests written for ``nose`` has been officially deprecated.
+
+This includes:
+
+* Plain ``setup`` and ``teardown`` functions and methods: this might catch users by surprise, as ``setup()`` and ``teardown()`` are not pytest idioms, but part of the ``nose`` support.
+* Setup/teardown using the `@with_setup <with-setup-nose>`_ decorator.
+
+For more details, consult the :ref:`deprecation docs <nose-deprecation>`.
+
+.. _`with-setup-nose`: https://nose.readthedocs.io/en/latest/testing_tools.html?highlight=with_setup#nose.tools.with_setup

doc/en/deprecations.rst

@@ -18,6 +18,113 @@ Deprecated Features
 Below is a complete list of all pytest features which are considered deprecated. Using those features will issue
 :class:`~pytest.PytestWarning` or subclasses, which can be filtered using :ref:`standard warning filters <warnings>`.
 
+
+.. _nose-deprecation:
+
+Support for tests written for nose
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. deprecated:: 7.2
+
+Support for running tests written for `nose <https://nose.readthedocs.io/en/latest/>`__ is now deprecated.
+
+``nose`` has been in maintenance mode-only for years, and maintaining the plugin is not trivial as it spills
+over the code base (see :issue:`9886` for more details).
+
+setup/teardown
+^^^^^^^^^^^^^^
+
+One thing that might catch users by surprise is that plain ``setup`` and ``teardown`` methods are not pytest native,
+they are in fact part of the ``nose`` support.
+
+
+.. code-block:: python
+
+    class Test:
+        def setup(self):
+            self.resource = make_resource()
+
+        def teardown(self):
+            self.resource.close()
+
+        def test_foo(self):
+            ...
+
+        def test_bar(self):
+            ...
+
+
+
+Native pytest support uses ``setup_method`` and ``teardown_method`` (see :ref:`xunit-method-setup`), so the above should be changed to:
+
+.. code-block:: python
+
+    class Test:
+        def setup_method(self):
+            self.resource = make_resource()
+
+        def teardown_method(self):
+            self.resource.close()
+
+        def test_foo(self):
+            ...
+
+        def test_bar(self):
+            ...
+
+
+This is easy to do in an entire code base by doing a simple find/replace.
+
+@with_setup
+^^^^^^^^^^^
+
+Code using `@with_setup <with-setup-nose>`_ such as this:
+
+.. code-block:: python
+
+    from nose.tools import with_setup
+
+
+    def setup_some_resource():
+        ...
+
+
+    def teardown_some_resource():
+        ...
+
+
+    @with_setup(setup_some_resource, teardown_some_resource)
+    def test_foo():
+        ...
+
+Will also need to be ported to a supported pytest style. One way to do it is using a fixture:
+
+.. code-block:: python
+
+    import pytest
+
+
+    def setup_some_resource():
+        ...
+
+
+    def teardown_some_resource():
+        ...
+
+
+    @pytest.fixture
+    def some_resource():
+        setup_some_resource()
+        yield
+        teardown_some_resource()
+
+
+    def test_foo(some_resource):
+        ...
+
+
+.. _`with-setup-nose`: https://nose.readthedocs.io/en/latest/testing_tools.html?highlight=with_setup#nose.tools.with_setup
+
 .. _instance-collector-deprecation:
 
 The ``pytest.Instance`` collector

doc/en/how-to/nose.rst

@@ -5,6 +5,9 @@ How to run tests written for nose
 
 ``pytest`` has basic support for running tests written for nose_.
 
+.. warning::
+    This functionality has been deprecated and is likely to be removed in ``pytest 8.x``.
+
 .. _nosestyle:
 
 Usage

doc/en/how-to/xunit_setup.rst

@@ -63,6 +63,8 @@ and after all test methods of the class are called:
         setup_class.
         """
 
+.. _xunit-method-setup:
+
 Method and function level setup/teardown
 -----------------------------------------------
 

src/_pytest/deprecated.py

@@ -22,6 +22,21 @@
     "pytest_faulthandler",
 }
 
+NOSE_SUPPORT = UnformattedWarning(
+    PytestRemovedIn8Warning,
+    "Support for nose tests is deprecated and will be removed in a future release.\n"
+    "{nodeid} is using nose method: `{method}` ({stage})\n"
+    "See docs: https://docs.pytest.org/en/stable/deprecations.html#support-for-tests-written-for-nose",
+)
+
+NOSE_SUPPORT_METHOD = UnformattedWarning(
+    PytestRemovedIn8Warning,
+    "Support for nose tests is deprecated and will be removed in a future release.\n"
+    "{nodeid} is using nose-specific method: `{method}(self)`\n"
+    "To remove this warning, rename it to `{method}_method(self)`\n"
+    "See docs: https://docs.pytest.org/en/stable/deprecations.html#support-for-tests-written-for-nose",
+)
+
 
 # This can be* removed pytest 8, but it's harmless and common, so no rush to remove.
 # * If you're in the future: "could have been".

src/_pytest/nose.py

@@ -1,5 +1,8 @@
 """Run testsuites written for nose."""
+import warnings
+
 from _pytest.config import hookimpl
+from _pytest.deprecated import NOSE_SUPPORT
 from _pytest.fixtures import getfixturemarker
 from _pytest.nodes import Item
 from _pytest.python import Function
@@ -18,16 +21,16 @@ def pytest_runtest_setup(item: Item) -> None:
     # see https://github.com/python/mypy/issues/2608
     func = item
 
-    call_optional(func.obj, "setup")
-    func.addfinalizer(lambda: call_optional(func.obj, "teardown"))
+    call_optional(func.obj, "setup", func.nodeid)
+    func.addfinalizer(lambda: call_optional(func.obj, "teardown", func.nodeid))
 
     # NOTE: Module- and class-level fixtures are handled in python.py
     # with `pluginmanager.has_plugin("nose")` checks.
     # It would have been nicer to implement them outside of core, but
     # it's not straightforward.
 
 
-def call_optional(obj: object, name: str) -> bool:
+def call_optional(obj: object, name: str, nodeid: str) -> bool:
     method = getattr(obj, name, None)
     if method is None:
         return False
@@ -36,6 +39,11 @@ def call_optional(obj: object, name: str) -> bool:
         return False
     if not callable(method):
         return False
+    # Warn about deprecation of this plugin.
+    method_name = getattr(method, "__name__", str(method))
+    warnings.warn(
+        NOSE_SUPPORT.format(nodeid=nodeid, method=method_name, stage=name), stacklevel=2
+    )
     # If there are any problems allow the exception to raise rather than
     # silently ignoring it.
     method()

src/_pytest/python.py

@@ -59,6 +59,7 @@
 from _pytest.deprecated import check_ispytest
 from _pytest.deprecated import FSCOLLECTOR_GETHOOKPROXY_ISINITPATH
 from _pytest.deprecated import INSTANCE_COLLECTOR
+from _pytest.deprecated import NOSE_SUPPORT_METHOD
 from _pytest.fixtures import FuncFixtureInfo
 from _pytest.main import Session
 from _pytest.mark import MARK_GEN
@@ -872,19 +873,23 @@ def _inject_setup_method_fixture(self) -> None:
         """Inject a hidden autouse, function scoped fixture into the collected class object
         that invokes setup_method/teardown_method if either or both are available.
 
-        Using a fixture to invoke this methods ensures we play nicely and unsurprisingly with
+        Using a fixture to invoke these methods ensures we play nicely and unsurprisingly with
         other fixtures (#517).
         """
         has_nose = self.config.pluginmanager.has_plugin("nose")
         setup_name = "setup_method"
         setup_method = _get_first_non_fixture_func(self.obj, (setup_name,))
+        emit_nose_setup_warning = False
         if setup_method is None and has_nose:
             setup_name = "setup"
+            emit_nose_setup_warning = True
             setup_method = _get_first_non_fixture_func(self.obj, (setup_name,))
         teardown_name = "teardown_method"
         teardown_method = getattr(self.obj, teardown_name, None)
+        emit_nose_teardown_warning = False
         if teardown_method is None and has_nose:
             teardown_name = "teardown"
+            emit_nose_teardown_warning = True
             teardown_method = getattr(self.obj, teardown_name, None)
         if setup_method is None and teardown_method is None:
             return
@@ -900,10 +905,24 @@ def xunit_setup_method_fixture(self, request) -> Generator[None, None, None]:
             if setup_method is not None:
                 func = getattr(self, setup_name)
                 _call_with_optional_argument(func, method)
+                if emit_nose_setup_warning:
+                    warnings.warn(
+                        NOSE_SUPPORT_METHOD.format(
+                            nodeid=request.node.nodeid, method="setup"
+                        ),
+                        stacklevel=2,
+                    )
             yield
             if teardown_method is not None:
                 func = getattr(self, teardown_name)
                 _call_with_optional_argument(func, method)
+                if emit_nose_teardown_warning:
+                    warnings.warn(
+                        NOSE_SUPPORT_METHOD.format(
+                            nodeid=request.node.nodeid, method="teardown"
+                        ),
+                        stacklevel=2,
+                    )
 
         self.obj.__pytest_setup_method = xunit_setup_method_fixture
 

testing/deprecated_test.py

@@ -279,3 +279,62 @@ def test_importing_instance_is_deprecated(pytester: Pytester) -> None:
         match=re.escape("The pytest.Instance collector type is deprecated"),
     ):
         from _pytest.python import Instance  # noqa: F401
+
+
+@pytest.mark.filterwarnings("default")
+def test_nose_deprecated_with_setup(pytester: Pytester) -> None:
+    pytest.importorskip("nose")
+    pytester.makepyfile(
+        """
+        from nose.tools import with_setup
+
+        def setup_fn_no_op():
+            ...
+
+        def teardown_fn_no_op():
+            ...
+
+        @with_setup(setup_fn_no_op, teardown_fn_no_op)
+        def test_omits_warnings():
+            ...
+        """
+    )
+    output = pytester.runpytest()
+    message = [
+        "*PytestRemovedIn8Warning: Support for nose tests is deprecated and will be removed in a future release.",
+        "*test_nose_deprecated_with_setup.py::test_omits_warnings is using nose method: `setup_fn_no_op` (setup)",
+        "*PytestRemovedIn8Warning: Support for nose tests is deprecated and will be removed in a future release.",
+        "*test_nose_deprecated_with_setup.py::test_omits_warnings is using nose method: `teardown_fn_no_op` (teardown)",
+    ]
+    output.stdout.fnmatch_lines(message)
+    output.assert_outcomes(passed=1)
+
+
+@pytest.mark.filterwarnings("default")
+def test_nose_deprecated_setup_teardown(pytester: Pytester) -> None:
+    pytest.importorskip("nose")
+    pytester.makepyfile(
+        """
+        class Test:
+
+            def setup(self):
+                ...
+
+            def teardown(self):
+                ...
+
+            def test(self):
+                ...
+        """
+    )
+    output = pytester.runpytest()
+    message = [
+        "*PytestRemovedIn8Warning: Support for nose tests is deprecated and will be removed in a future release.",
+        "*test_nose_deprecated_setup_teardown.py::Test::test is using nose-specific method: `setup(self)`",
+        "*To remove this warning, rename it to `setup_method(self)`",
+        "*PytestRemovedIn8Warning: Support for nose tests is deprecated and will be removed in a future release.",
+        "*test_nose_deprecated_setup_teardown.py::Test::test is using nose-specific method: `teardown(self)`",
+        "*To remove this warning, rename it to `teardown_method(self)`",
+    ]
+    output.stdout.fnmatch_lines(message)
+    output.assert_outcomes(passed=1)

testing/test_nose.py

@@ -37,7 +37,7 @@ class A:
         def f(self):
             values.append(1)
 
-    call_optional(A(), "f")
+    call_optional(A(), "f", "A.f")
     assert not values
 
 
@@ -47,7 +47,7 @@ def test_setup_func_not_callable() -> None:
     class A:
         f = 1
 
-    call_optional(A(), "f")
+    call_optional(A(), "f", "A.f")
 
 
 def test_nose_setup_func(pytester: Pytester) -> None: