argparsing: export Parser and OptionGroup for typing purposes

`Parser` is used by many plugins and custom hooks. `OptionGroup` is
exposed by the `parser.addgroup` API.

The constructors of both are marked private, they are not meant to be
constructed directly.

changelog/7259.feature.rst

@@ -1,7 +1,7 @@
 Added :meth:`cache.mkdir() <pytest.Cache.mkdir>`, which is similar to the existing :meth:`cache.makedir() <pytest.Cache.makedir>`,
 but returns a :class:`pathlib.Path` instead of a legacy ``py.path.local``.
 
-Added a ``paths`` type to :meth:`parser.addini() <_pytest.config.argparsing.Parser.addini>`,
+Added a ``paths`` type to :meth:`parser.addini() <pytest.Parser.addini>`,
 as in ``parser.addini("mypaths", "my paths", type="paths")``,
 which is similar to the existing ``pathlist``,
 but returns a list of :class:`pathlib.Path` instead of legacy ``py.path.local``.

changelog/7469.deprecation.rst

@@ -6,5 +6,7 @@ Directly constructing the following classes is now deprecated:
 - ``_pytest.python.Metafunc``
 - ``_pytest.runner.CallInfo``
 - ``_pytest._code.ExceptionInfo``
+- ``_pytest.config.argparsing.Parser``
+- ``_pytest.config.argparsing.OptionGroup``
 
 These have always been considered private, but now issue a deprecation warning, which may become a hard error in pytest 7.0.0.

changelog/7469.feature.rst

@@ -8,6 +8,8 @@ The newly-exported types are:
 - ``pytest.Metafunc`` for the :class:`metafunc <pytest.MarkGenerator>` argument to the :func:`pytest_generate_tests <pytest.hookspec.pytest_generate_tests>` hook.
 - ``pytest.CallInfo`` for the :class:`CallInfo <pytest.CallInfo>` type passed to various hooks.
 - ``pytest.ExceptionInfo`` for the :class:`ExceptionInfo <pytest.ExceptionInfo>` type returned from :func:`pytest.raises` and passed to various hooks.
+- ``pytest.Parser`` for the :class:`Parser <pytest.Parser>` type passed to the :func:`pytest_addoption <pytest.hookspec.pytest_addoption>` hook.
+- ``pytest.OptionGroup`` for the :class:`OptionGroup <pytest.OptionGroup>` type returned from the :func:`parser.addgroup <pytest.Parser.getgroup>` method.
 
 Constructing them directly is not supported; they are only meant for use in type annotations.
 Doing so will emit a deprecation warning, and may become a hard-error in pytest 7.0.

changelog/8315.deprecation.rst

@@ -1,4 +1,4 @@
-Several behaviors of :meth:`Parser.addoption <_pytest.config.argparsing.Parser.addoption>` are now
+Several behaviors of :meth:`Parser.addoption <pytest.Parser.addoption>` are now
 scheduled for removal in pytest 7 (deprecated since pytest 2.4.0):
 
 - ``parser.addoption(..., help=".. %default ..")`` - use ``%(default)s`` instead.

doc/en/deprecations.rst

@@ -48,7 +48,7 @@ Backward compatibilities in ``Parser.addoption``
 
 .. deprecated:: 2.4
 
-Several behaviors of :meth:`Parser.addoption <_pytest.config.argparsing.Parser.addoption>` are now
+Several behaviors of :meth:`Parser.addoption <pytest.Parser.addoption>` are now
 scheduled for removal in pytest 7 (deprecated since pytest 2.4.0):
 
 - ``parser.addoption(..., help=".. %default ..")`` - use ``%(default)s`` instead.

doc/en/reference/reference.rst

@@ -889,9 +889,14 @@ Node
 Parser
 ~~~~~~
 
-.. autoclass:: _pytest.config.argparsing.Parser()
+.. autoclass:: pytest.Parser()
     :members:
 
+OptionGroup
+~~~~~~~~~~~
+
+.. autoclass:: pytest.OptionGroup()
+    :members:
 
 PytestPluginManager
 ~~~~~~~~~~~~~~~~~~~

src/_pytest/config/__init__.py

@@ -909,6 +909,7 @@ class Config:
         self._parser = Parser(
             usage=f"%(prog)s [options] [{_a}] [{_a}] [...]",
             processopt=self._processopt,
+            _ispytest=True,
         )
         self.pluginmanager = pluginmanager
         """The plugin manager handles plugin registration and hook invocation.
@@ -1380,8 +1381,8 @@ class Config:
         """Return configuration value from an :ref:`ini file <configfiles>`.
 
         If the specified name hasn't been registered through a prior
-        :py:func:`parser.addini <_pytest.config.argparsing.Parser.addini>`
+        :func:`parser.addini <pytest.Parser.addini>` call (usually from a
-        call (usually from a plugin), a ValueError is raised.
+        plugin), a ValueError is raised.
         """
         try:
             return self._inicache[name]

src/_pytest/config/argparsing.py

@@ -21,6 +21,7 @@ from _pytest.config.exceptions import UsageError
 from _pytest.deprecated import ARGUMENT_PERCENT_DEFAULT
 from _pytest.deprecated import ARGUMENT_TYPE_STR
 from _pytest.deprecated import ARGUMENT_TYPE_STR_CHOICE
+from _pytest.deprecated import check_ispytest
 
 if TYPE_CHECKING:
     from typing import NoReturn
@@ -43,8 +44,11 @@ class Parser:
         self,
         usage: Optional[str] = None,
         processopt: Optional[Callable[["Argument"], None]] = None,
+        *,
+        _ispytest: bool = False,
     ) -> None:
-        self._anonymous = OptionGroup("custom options", parser=self)
+        check_ispytest(_ispytest)
+        self._anonymous = OptionGroup("custom options", parser=self, _ispytest=True)
         self._groups: List[OptionGroup] = []
         self._processopt = processopt
         self._usage = usage
@@ -67,14 +71,14 @@ class Parser:
         :after: Name of another group, used for ordering --help output.
 
         The returned group object has an ``addoption`` method with the same
-        signature as :py:func:`parser.addoption
+        signature as :func:`parser.addoption <pytest.Parser.addoption>` but
-        <_pytest.config.argparsing.Parser.addoption>` but will be shown in the
+        will be shown in the respective group in the output of
-        respective group in the output of ``pytest. --help``.
+        ``pytest. --help``.
         """
         for group in self._groups:
             if group.name == name:
                 return group
-        group = OptionGroup(name, description, parser=self)
+        group = OptionGroup(name, description, parser=self, _ispytest=True)
         i = 0
         for i, grp in enumerate(self._groups):
             if grp.name == after:
@@ -334,9 +338,17 @@ class Argument:
 
 
 class OptionGroup:
+    """A group of options shown in its own section."""
+
     def __init__(
-        self, name: str, description: str = "", parser: Optional[Parser] = None
+        self,
+        name: str,
+        description: str = "",
+        parser: Optional[Parser] = None,
+        *,
+        _ispytest: bool = False,
     ) -> None:
+        check_ispytest(_ispytest)
         self.name = name
         self.description = description
         self.options: List[Argument] = []
@@ -346,9 +358,9 @@ class OptionGroup:
         """Add an option to this group.
 
         If a shortened version of a long option is specified, it will
-        be suppressed in the help. addoption('--twowords', '--two-words')
+        be suppressed in the help. ``addoption('--twowords', '--two-words')``
-        results in help showing '--two-words' only, but --twowords gets
+        results in help showing ``--two-words`` only, but ``--twowords`` gets
-        accepted **and** the automatic destination is in args.twowords.
+        accepted **and** the automatic destination is in ``args.twowords``.
         """
         conflict = set(optnames).intersection(
             name for opt in self.options for name in opt.names()

src/_pytest/hookspec.py

@@ -88,11 +88,11 @@ def pytest_addoption(parser: "Parser", pluginmanager: "PytestPluginManager") ->
         files situated at the tests root directory due to how pytest
         :ref:`discovers plugins during startup <pluginorder>`.
 
-    :param _pytest.config.argparsing.Parser parser:
+    :param pytest.Parser parser:
         To add command line options, call
-        :py:func:`parser.addoption(...) <_pytest.config.argparsing.Parser.addoption>`.
+        :py:func:`parser.addoption(...) <pytest.Parser.addoption>`.
         To add ini-file values call :py:func:`parser.addini(...)
-        <_pytest.config.argparsing.Parser.addini>`.
+        <pytest.Parser.addini>`.
 
     :param _pytest.config.PytestPluginManager pluginmanager:
         pytest plugin manager, which can be used to install :py:func:`hookspec`'s
@@ -193,7 +193,7 @@ def pytest_load_initial_conftests(
 
     :param _pytest.config.Config early_config: The pytest config object.
     :param List[str] args: Arguments passed on the command line.
-    :param _pytest.config.argparsing.Parser parser: To add command line options.
+    :param pytest.Parser parser: To add command line options.
     """
 
 

src/pytest/__init__.py

@@ -13,6 +13,8 @@ from _pytest.config import hookimpl
 from _pytest.config import hookspec
 from _pytest.config import main
 from _pytest.config import UsageError
+from _pytest.config.argparsing import OptionGroup
+from _pytest.config.argparsing import Parser
 from _pytest.debugging import pytestPDB as __pytestPDB
 from _pytest.fixtures import _fillfuncargs
 from _pytest.fixtures import fixture
@@ -103,8 +105,10 @@ __all__ = [
     "Metafunc",
     "Module",
     "MonkeyPatch",
+    "OptionGroup",
     "Package",
     "param",
+    "Parser",
     "PytestAssertRewriteWarning",
     "PytestCacheWarning",
     "PytestCollectionWarning",

testing/test_parseopt.py

@@ -14,12 +14,12 @@ from _pytest.pytester import Pytester
 
 @pytest.fixture
 def parser() -> parseopt.Parser:
-    return parseopt.Parser()
+    return parseopt.Parser(_ispytest=True)
 
 
 class TestParser:
     def test_no_help_by_default(self) -> None:
-        parser = parseopt.Parser(usage="xyz")
+        parser = parseopt.Parser(usage="xyz", _ispytest=True)
         pytest.raises(UsageError, lambda: parser.parse(["-h"]))
 
     def test_custom_prog(self, parser: parseopt.Parser) -> None:
@@ -90,13 +90,13 @@ class TestParser:
         assert groups_names == list("132")
 
     def test_group_addoption(self) -> None:
-        group = parseopt.OptionGroup("hello")
+        group = parseopt.OptionGroup("hello", _ispytest=True)
         group.addoption("--option1", action="store_true")
         assert len(group.options) == 1
         assert isinstance(group.options[0], parseopt.Argument)
 
     def test_group_addoption_conflict(self) -> None:
-        group = parseopt.OptionGroup("hello again")
+        group = parseopt.OptionGroup("hello again", _ispytest=True)
         group.addoption("--option1", "--option-1", action="store_true")
         with pytest.raises(ValueError) as err:
             group.addoption("--option1", "--option-one", action="store_true")
@@ -188,7 +188,7 @@ class TestParser:
             elif option.type is str:
                 option.default = "world"
 
-        parser = parseopt.Parser(processopt=defaultget)
+        parser = parseopt.Parser(processopt=defaultget, _ispytest=True)
         parser.addoption("--this", dest="this", type=int, action="store")
         parser.addoption("--hello", dest="hello", type=str, action="store")
         parser.addoption("--no", dest="no", action="store_true")