Add strict_config, strict_markers ini options, same as CLI flags

We want to have ini versions of all strictness flags, since they're
usually more sensible as project configuration, and as preparation for
adding the `strict` ini option.

Refs #13823.

Author: bluetech

changelog/13823.improvement.rst

@@ -1,2 +1,4 @@
-Added :confval:`strict_xfail` as an alias to the ``xfail_strict`` option.
-This makes it consistent with other strictness options.
+Added :confval:`strict_xfail` as an alias to the ``xfail_strict`` option,
+:confval:`strict_config` as an alias to the ``--strict-config`` flag,
+and :confval:`strict_markers` as an alias to the ``--strict-markers`` flag.
+This makes all strictness options consistently have configuration options with the prefix ``strict_``.

doc/en/example/markers.rst

@@ -286,8 +286,7 @@ For an example on how to add and work with markers from a plugin, see
 
     * Asking for existing markers via ``pytest --markers`` gives good output
 
-    * Typos in function markers are treated as an error if you use
-      the ``--strict-markers`` option.
+    * Typos in function markers are treated as an error if you use the :confval:`strict_markers` configuration option.
 
 .. _`scoped-marking`:
 

doc/en/how-to/mark.rst

@@ -80,14 +80,14 @@ surprising due to mistyped names. As described in the previous section, you can
 the warning for custom marks by registering them in your ``pytest.ini`` file or
 using a custom ``pytest_configure`` hook.
 
-When the ``--strict-markers`` command-line flag is passed, any unknown marks applied
+When the :confval:`strict_markers` ini option is set, any unknown marks applied
 with the ``@pytest.mark.name_of_the_mark`` decorator will trigger an error. You can
-enforce this validation in your project by adding ``--strict-markers`` to ``addopts``:
+enforce this validation in your project by setting :confval:`strict_markers` in your configuration:
 
 .. code-block:: ini
 
     [pytest]
-    addopts = --strict-markers
+    strict_markers = True
     markers =
         slow: marks tests as slow (deselect with '-m "not slow"')
         serial

doc/en/reference/reference.rst

@@ -1774,25 +1774,21 @@ passed multiple times. The expected format is ``name=value``. For example::
 
 .. confval:: markers
 
-    When the ``--strict-markers`` or ``--strict`` command-line arguments are used,
+    When the :confval:`strict_markers` configuration option is set,
     only known markers - defined in code by core pytest or some plugin - are allowed.
 
     You can list additional markers in this setting to add them to the whitelist,
-    in which case you probably want to add ``--strict-markers`` to ``addopts``
+    in which case you probably want to set :confval:`strict_markers` to ``True``
     to avoid future regressions:
 
     .. code-block:: ini
 
         [pytest]
-        addopts = --strict-markers
+        strict_markers = True
         markers =
             slow
             serial
 
-    .. note::
-        The use of ``--strict-markers`` is highly preferred. ``--strict`` was kept for
-        backward compatibility only and may be confusing for others as it only applies to
-        markers and not to other options.
 
 .. confval:: minversion
 
@@ -2086,6 +2082,27 @@ passed multiple times. The expected format is ``name=value``. For example::
         Renamed from ``xfail_strict`` to ``strict_xfail``.
         ``xfail_strict`` is accepted as an alias for ``strict_xfail``.
 
+
+.. confval:: strict_config
+
+    If set to ``True``, any warnings encountered while parsing the ``pytest`` section of the configuration file will raise errors.
+
+    .. code-block:: ini
+
+        [pytest]
+        strict_config = True
+
+
+.. confval:: strict_markers
+
+    If set to ``True``, markers not registered in the ``markers`` section of the configuration file will raise errors.
+
+    .. code-block:: ini
+
+        [pytest]
+        strict_markers = True
+
+
 .. confval:: strict_parametrization_ids
 
     If set, pytest emits an error if it detects non-unique parameter set IDs.

pyproject.toml

@@ -355,7 +355,7 @@ max_supported_python = "3.14"
 
 [tool.pytest.ini_options]
 minversion = "2.0"
-addopts = "-rfEX -p pytester --strict-markers"
+addopts = "-rfEX -p pytester"
 python_files = [
     "test_*.py",
     "*_test.py",
@@ -380,6 +380,8 @@ norecursedirs = [
 ]
 strict_xfail = true
 strict_parametrization_ids = true
+strict_markers = true
+strict_config = true
 filterwarnings = [
     "error",
     "default:Using or importing the ABCs:DeprecationWarning:unittest2.*",

src/_pytest/config/__init__.py

@@ -1515,7 +1515,8 @@ def _validate_plugins(self) -> None:
             )
 
     def _warn_or_fail_if_strict(self, message: str) -> None:
-        if self.known_args_namespace.strict_config:
+        strict_config = self.getini("strict_config")
+        if strict_config:
             raise UsageError(message)
 
         self.issue_config_time_warning(PytestConfigWarning(message), stacklevel=3)

src/_pytest/config/argparsing.py

@@ -547,3 +547,40 @@ def _split_lines(self, text, width):
         for line in text.splitlines():
             lines.extend(textwrap.wrap(line.strip(), width))
         return lines
+
+
+class OverrideIniAction(argparse.Action):
+    """Custom argparse action that makes a CLI flag equivalent to overriding an
+    option, in addition to behaving like `store_true`.
+
+    This can simplify things since code only needs to inspect the ini option
+    and not consider the CLI flag.
+    """
+
+    def __init__(
+        self,
+        option_strings: Sequence[str],
+        dest: str,
+        nargs: int | str | None = None,
+        *args,
+        ini_option: str,
+        ini_value: str,
+        **kwargs,
+    ) -> None:
+        super().__init__(option_strings, dest, 0, *args, **kwargs)
+        self.ini_option = ini_option
+        self.ini_value = ini_value
+
+    def __call__(
+        self,
+        parser: argparse.ArgumentParser,
+        namespace: argparse.Namespace,
+        *args,
+        **kwargs,
+    ) -> None:
+        setattr(namespace, self.dest, True)
+        current_overrides = getattr(namespace, "override_ini", None)
+        if current_overrides is None:
+            current_overrides = []
+        current_overrides.append(f"{self.ini_option}={self.ini_value}")
+        setattr(namespace, "override_ini", current_overrides)

src/_pytest/main.py

@@ -32,6 +32,7 @@
 from _pytest.config import hookimpl
 from _pytest.config import PytestPluginManager
 from _pytest.config import UsageError
+from _pytest.config.argparsing import OverrideIniAction
 from _pytest.config.argparsing import Parser
 from _pytest.config.compat import PathAwareHookProxy
 from _pytest.outcomes import exit
@@ -75,21 +76,37 @@ def pytest_addoption(parser: Parser) -> None:
     )
     group.addoption(
         "--strict-config",
-        action="store_true",
-        help="Any warnings encountered while parsing the `pytest` section of the "
-        "configuration file raise errors",
+        action=OverrideIniAction,
+        ini_option="strict_config",
+        ini_value="true",
+        help="Enables the strict_config option",
     )
     group.addoption(
         "--strict-markers",
-        action="store_true",
-        help="Markers not registered in the `markers` section of the configuration "
-        "file raise errors",
+        action=OverrideIniAction,
+        ini_option="strict_markers",
+        ini_value="true",
+        help="Enables the strict_markers option",
     )
     group.addoption(
         "--strict",
         action="store_true",
         help="(Deprecated) alias to --strict-markers",
     )
+    parser.addini(
+        "strict_config",
+        "Any warnings encountered while parsing the `pytest` section of the "
+        "configuration file raise errors",
+        type="bool",
+        default=False,
+    )
+    parser.addini(
+        "strict_markers",
+        "Markers not registered in the `markers` section of the configuration "
+        "file raise errors",
+        type="bool",
+        default=False,
+    )
 
     group = parser.getgroup("pytest-warnings")
     group.addoption(

src/_pytest/mark/structures.py

@@ -580,7 +580,10 @@ def __getattr__(self, name: str) -> MarkDecorator:
             # If the name is not in the set of known marks after updating,
             # then it really is time to issue a warning or an error.
             if name not in self._markers:
-                if self._config.option.strict_markers or self._config.option.strict:
+                strict_markers = (
+                    self._config.getini("strict_markers") or self._config.option.strict
+                )
+                if strict_markers:
                     fail(
                         f"{name!r} not found in `markers` configuration option",
                         pytrace=False,

testing/plugins_integration/pytest.ini

@@ -1,5 +1,5 @@
 [pytest]
-addopts = --strict-markers
+strict_markers = True
 asyncio_mode = strict
 filterwarnings =
     error::pytest.PytestWarning