Drop attrs dependency, use dataclasses instead (#10669)

Since pytest now requires Python>=3.7, we can use the stdlib attrs
clone, dataclasses, instead of the OG package.

attrs is still somewhat nicer than dataclasses and has some extra
functionality, but for pytest usage there's not really a justification
IMO to impose the extra dependency on users when a standard alternative
exists.

changelog/10669.trivial.rst

@@ -0,0 +1 @@
+pytest no longer depends on the `attrs` package (don't worry, nice diffs for attrs classes are still supported).

setup.cfg

@@ -44,7 +44,6 @@ packages =
     pytest
 py_modules = py
 install_requires =
-    attrs>=19.2.0
     iniconfig
     packaging
     pluggy>=0.12,<2.0
@@ -68,6 +67,7 @@ console_scripts =
 [options.extras_require]
 testing =
     argcomplete
+    attrs>=19.2.0
     hypothesis>=3.56
     mock
     nose

src/_pytest/_code/code.py

@@ -1,4 +1,5 @@
 import ast
+import dataclasses
 import inspect
 import os
 import re
@@ -32,7 +33,6 @@ from typing import TypeVar
 from typing import Union
 from weakref import ref
 
-import attr
 import pluggy
 
 import _pytest
@@ -445,7 +445,7 @@ E = TypeVar("E", bound=BaseException, covariant=True)
 
 
 @final
-@attr.s(repr=False, init=False, auto_attribs=True)
+@dataclasses.dataclass
 class ExceptionInfo(Generic[E]):
     """Wraps sys.exc_info() objects and offers help for navigating the traceback."""
 
@@ -649,12 +649,12 @@ class ExceptionInfo(Generic[E]):
         """
         if style == "native":
             return ReprExceptionInfo(
-                ReprTracebackNative(
+                reprtraceback=ReprTracebackNative(
                     traceback.format_exception(
                         self.type, self.value, self.traceback[0]._rawentry
                     )
                 ),
-                self._getreprcrash(),
+                reprcrash=self._getreprcrash(),
             )
 
         fmt = FormattedExcinfo(
@@ -684,7 +684,7 @@ class ExceptionInfo(Generic[E]):
         return True
 
 
-@attr.s(auto_attribs=True)
+@dataclasses.dataclass
 class FormattedExcinfo:
     """Presenting information about failing Functions and Generators."""
 
@@ -699,8 +699,8 @@ class FormattedExcinfo:
     funcargs: bool = False
     truncate_locals: bool = True
     chain: bool = True
-    astcache: Dict[Union[str, Path], ast.AST] = attr.ib(
+    astcache: Dict[Union[str, Path], ast.AST] = dataclasses.field(
-        factory=dict, init=False, repr=False
+        default_factory=dict, init=False, repr=False
     )
 
     def _getindent(self, source: "Source") -> int:
@@ -978,7 +978,7 @@ class FormattedExcinfo:
         return ExceptionChainRepr(repr_chain)
 
 
-@attr.s(eq=False, auto_attribs=True)
+@dataclasses.dataclass(eq=False)
 class TerminalRepr:
     def __str__(self) -> str:
         # FYI this is called from pytest-xdist's serialization of exception
@@ -996,14 +996,14 @@ class TerminalRepr:
 
 
 # This class is abstract -- only subclasses are instantiated.
-@attr.s(eq=False)
+@dataclasses.dataclass(eq=False)
 class ExceptionRepr(TerminalRepr):
     # Provided by subclasses.
-    reprcrash: Optional["ReprFileLocation"]
     reprtraceback: "ReprTraceback"
-
+    reprcrash: Optional["ReprFileLocation"]
-    def __attrs_post_init__(self) -> None:
+    sections: List[Tuple[str, str, str]] = dataclasses.field(
-        self.sections: List[Tuple[str, str, str]] = []
+        init=False, default_factory=list
+    )
 
     def addsection(self, name: str, content: str, sep: str = "-") -> None:
         self.sections.append((name, content, sep))
@@ -1014,16 +1014,23 @@ class ExceptionRepr(TerminalRepr):
             tw.line(content)
 
 
-@attr.s(eq=False, auto_attribs=True)
+@dataclasses.dataclass(eq=False)
 class ExceptionChainRepr(ExceptionRepr):
     chain: Sequence[Tuple["ReprTraceback", Optional["ReprFileLocation"], Optional[str]]]
 
-    def __attrs_post_init__(self) -> None:
+    def __init__(
-        super().__attrs_post_init__()
+        self,
+        chain: Sequence[
+            Tuple["ReprTraceback", Optional["ReprFileLocation"], Optional[str]]
+        ],
+    ) -> None:
         # reprcrash and reprtraceback of the outermost (the newest) exception
         # in the chain.
-        self.reprtraceback = self.chain[-1][0]
+        super().__init__(
-        self.reprcrash = self.chain[-1][1]
+            reprtraceback=chain[-1][0],
+            reprcrash=chain[-1][1],
+        )
+        self.chain = chain
 
     def toterminal(self, tw: TerminalWriter) -> None:
         for element in self.chain:
@@ -1034,7 +1041,7 @@ class ExceptionChainRepr(ExceptionRepr):
         super().toterminal(tw)
 
 
-@attr.s(eq=False, auto_attribs=True)
+@dataclasses.dataclass(eq=False)
 class ReprExceptionInfo(ExceptionRepr):
     reprtraceback: "ReprTraceback"
     reprcrash: "ReprFileLocation"
@@ -1044,7 +1051,7 @@ class ReprExceptionInfo(ExceptionRepr):
         super().toterminal(tw)
 
 
-@attr.s(eq=False, auto_attribs=True)
+@dataclasses.dataclass(eq=False)
 class ReprTraceback(TerminalRepr):
     reprentries: Sequence[Union["ReprEntry", "ReprEntryNative"]]
     extraline: Optional[str]
@@ -1073,12 +1080,12 @@ class ReprTraceback(TerminalRepr):
 
 class ReprTracebackNative(ReprTraceback):
     def __init__(self, tblines: Sequence[str]) -> None:
-        self.style = "native"
         self.reprentries = [ReprEntryNative(tblines)]
         self.extraline = None
+        self.style = "native"
 
 
-@attr.s(eq=False, auto_attribs=True)
+@dataclasses.dataclass(eq=False)
 class ReprEntryNative(TerminalRepr):
     lines: Sequence[str]
 
@@ -1088,7 +1095,7 @@ class ReprEntryNative(TerminalRepr):
         tw.write("".join(self.lines))
 
 
-@attr.s(eq=False, auto_attribs=True)
+@dataclasses.dataclass(eq=False)
 class ReprEntry(TerminalRepr):
     lines: Sequence[str]
     reprfuncargs: Optional["ReprFuncArgs"]
@@ -1168,12 +1175,15 @@ class ReprEntry(TerminalRepr):
         )
 
 
-@attr.s(eq=False, auto_attribs=True)
+@dataclasses.dataclass(eq=False)
 class ReprFileLocation(TerminalRepr):
-    path: str = attr.ib(converter=str)
+    path: str
     lineno: int
     message: str
 
+    def __post_init__(self) -> None:
+        self.path = str(self.path)
+
     def toterminal(self, tw: TerminalWriter) -> None:
         # Filename and lineno output for each entry, using an output format
         # that most editors understand.
@@ -1185,7 +1195,7 @@ class ReprFileLocation(TerminalRepr):
         tw.line(f":{self.lineno}: {msg}")
 
 
-@attr.s(eq=False, auto_attribs=True)
+@dataclasses.dataclass(eq=False)
 class ReprLocals(TerminalRepr):
     lines: Sequence[str]
 
@@ -1194,7 +1204,7 @@ class ReprLocals(TerminalRepr):
             tw.line(indent + line)
 
 
-@attr.s(eq=False, auto_attribs=True)
+@dataclasses.dataclass(eq=False)
 class ReprFuncArgs(TerminalRepr):
     args: Sequence[Tuple[str, object]]
 

src/_pytest/cacheprovider.py

@@ -1,6 +1,7 @@
 """Implementation of the cache provider."""
 # This plugin was not named "cache" to avoid conflicts with the external
 # pytest-cache version.
+import dataclasses
 import json
 import os
 from pathlib import Path
@@ -12,8 +13,6 @@ from typing import Optional
 from typing import Set
 from typing import Union
 
-import attr
-
 from .pathlib import resolve_from_str
 from .pathlib import rm_rf
 from .reports import CollectReport
@@ -52,10 +51,12 @@ Signature: 8a477f597d28d172789f06886806bc55
 
 
 @final
-@attr.s(init=False, auto_attribs=True)
+@dataclasses.dataclass
 class Cache:
-    _cachedir: Path = attr.ib(repr=False)
+    """Instance of the `cache` fixture."""
-    _config: Config = attr.ib(repr=False)
+
+    _cachedir: Path = dataclasses.field(repr=False)
+    _config: Config = dataclasses.field(repr=False)
 
     # Sub-directory under cache-dir for directories created by `mkdir()`.
     _CACHE_PREFIX_DIRS = "d"

src/_pytest/compat.py

@@ -1,4 +1,5 @@
 """Python version compatibility code."""
+import dataclasses
 import enum
 import functools
 import inspect
@@ -17,8 +18,6 @@ from typing import TYPE_CHECKING
 from typing import TypeVar
 from typing import Union
 
-import attr
-
 import py
 
 # fmt: off
@@ -253,7 +252,7 @@ def ascii_escaped(val: Union[bytes, str]) -> str:
     return _translate_non_printable(ret)
 
 
-@attr.s
+@dataclasses.dataclass
 class _PytestWrapper:
     """Dummy wrapper around a function object for internal use only.
 
@@ -262,7 +261,7 @@ class _PytestWrapper:
     decorator to issue warnings when the fixture function is called directly.
     """
 
-    obj = attr.ib()
+    obj: Any
 
 
 def get_real_func(obj):

src/_pytest/config/__init__.py

@@ -2,6 +2,7 @@
 import argparse
 import collections.abc
 import copy
+import dataclasses
 import enum
 import glob
 import inspect
@@ -34,7 +35,6 @@ from typing import Type
 from typing import TYPE_CHECKING
 from typing import Union
 
-import attr
 from pluggy import HookimplMarker
 from pluggy import HookspecMarker
 from pluggy import PluginManager
@@ -886,10 +886,6 @@ def _iter_rewritable_modules(package_files: Iterable[str]) -> Iterator[str]:
             yield from _iter_rewritable_modules(new_package_files)
 
 
-def _args_converter(args: Iterable[str]) -> Tuple[str, ...]:
-    return tuple(args)
-
-
 @final
 class Config:
     """Access to configuration values, pluginmanager and plugin hooks.
@@ -903,7 +899,7 @@ class Config:
     """
 
     @final
-    @attr.s(frozen=True, auto_attribs=True)
+    @dataclasses.dataclass(frozen=True)
     class InvocationParams:
         """Holds parameters passed during :func:`pytest.main`.
 
@@ -919,13 +915,24 @@ class Config:
             Plugins accessing ``InvocationParams`` must be aware of that.
         """
 
-        args: Tuple[str, ...] = attr.ib(converter=_args_converter)
+        args: Tuple[str, ...]
         """The command-line arguments as passed to :func:`pytest.main`."""
         plugins: Optional[Sequence[Union[str, _PluggyPlugin]]]
         """Extra plugins, might be `None`."""
         dir: Path
         """The directory from which :func:`pytest.main` was invoked."""
 
+        def __init__(
+            self,
+            *,
+            args: Iterable[str],
+            plugins: Optional[Sequence[Union[str, _PluggyPlugin]]],
+            dir: Path,
+        ) -> None:
+            object.__setattr__(self, "args", tuple(args))
+            object.__setattr__(self, "plugins", plugins)
+            object.__setattr__(self, "dir", dir)
+
     class ArgsSource(enum.Enum):
         """Indicates the source of the test arguments.
 

src/_pytest/fixtures.py

@@ -1,3 +1,4 @@
+import dataclasses
 import functools
 import inspect
 import os
@@ -28,8 +29,6 @@ from typing import TYPE_CHECKING
 from typing import TypeVar
 from typing import Union
 
-import attr
-
 import _pytest
 from _pytest import nodes
 from _pytest._code import getfslineno
@@ -103,7 +102,7 @@ _FixtureCachedResult = Union[
 ]
 
 
-@attr.s(frozen=True, auto_attribs=True)
+@dataclasses.dataclass(frozen=True)
 class PseudoFixtureDef(Generic[FixtureValue]):
     cached_result: "_FixtureCachedResult[FixtureValue]"
     _scope: Scope
@@ -350,8 +349,10 @@ def get_direct_param_fixture_func(request: "FixtureRequest") -> Any:
     return request.param
 
 
-@attr.s(slots=True, auto_attribs=True)
+@dataclasses.dataclass
 class FuncFixtureInfo:
+    __slots__ = ("argnames", "initialnames", "names_closure", "name2fixturedefs")
+
     # Original function argument names.
     argnames: Tuple[str, ...]
     # Argnames that function immediately requires. These include argnames +
@@ -1181,19 +1182,21 @@ def wrap_function_to_error_out_if_called_directly(
 
 
 @final
-@attr.s(frozen=True, auto_attribs=True)
+@dataclasses.dataclass(frozen=True)
 class FixtureFunctionMarker:
     scope: "Union[_ScopeName, Callable[[str, Config], _ScopeName]]"
-    params: Optional[Tuple[object, ...]] = attr.ib(converter=_params_converter)
+    params: Optional[Tuple[object, ...]]
     autouse: bool = False
     ids: Optional[
         Union[Tuple[Optional[object], ...], Callable[[Any], Optional[object]]]
-    ] = attr.ib(
+    ] = None
-        default=None,
-        converter=_ensure_immutable_ids,
-    )
     name: Optional[str] = None
 
+    _ispytest: dataclasses.InitVar[bool] = False
+
+    def __post_init__(self, _ispytest: bool) -> None:
+        check_ispytest(_ispytest)
+
     def __call__(self, function: FixtureFunction) -> FixtureFunction:
         if inspect.isclass(function):
             raise ValueError("class fixtures not supported (maybe in the future)")
@@ -1313,10 +1316,11 @@ def fixture(  # noqa: F811
     """
     fixture_marker = FixtureFunctionMarker(
         scope=scope,
-        params=params,
+        params=tuple(params) if params is not None else None,
         autouse=autouse,
-        ids=ids,
+        ids=None if ids is None else ids if callable(ids) else tuple(ids),
         name=name,
+        _ispytest=True,
     )
 
     # Direct decoration.

src/_pytest/legacypath.py

@@ -1,4 +1,5 @@
 """Add backward compatibility support for the legacy py path type."""
+import dataclasses
 import shlex
 import subprocess
 from pathlib import Path
@@ -7,7 +8,6 @@ from typing import Optional
 from typing import TYPE_CHECKING
 from typing import Union
 
-import attr
 from iniconfig import SectionWrapper
 
 from _pytest.cacheprovider import Cache
@@ -268,7 +268,7 @@ class LegacyTestdirPlugin:
 
 
 @final
-@attr.s(init=False, auto_attribs=True)
+@dataclasses.dataclass
 class TempdirFactory:
     """Backward compatibility wrapper that implements :class:`py.path.local`
     for :class:`TempPathFactory`.

src/_pytest/main.py

@@ -1,5 +1,6 @@
 """Core implementation of the testing process: init, session, runtest loop."""
 import argparse
+import dataclasses
 import fnmatch
 import functools
 import importlib
@@ -19,8 +20,6 @@ from typing import Type
 from typing import TYPE_CHECKING
 from typing import Union
 
-import attr
-
 import _pytest._code
 from _pytest import nodes
 from _pytest.compat import final
@@ -442,8 +441,10 @@ class Failed(Exception):
     """Signals a stop as failed test run."""
 
 
-@attr.s(slots=True, auto_attribs=True)
+@dataclasses.dataclass
 class _bestrelpath_cache(Dict[Path, str]):
+    __slots__ = ("path",)
+
     path: Path
 
     def __missing__(self, path: Path) -> str:

src/_pytest/mark/__init__.py

@@ -1,4 +1,5 @@
 """Generic mechanism for marking and selecting python functions."""
+import dataclasses
 from typing import AbstractSet
 from typing import Collection
 from typing import List
@@ -6,8 +7,6 @@ from typing import Optional
 from typing import TYPE_CHECKING
 from typing import Union
 
-import attr
-
 from .expression import Expression
 from .expression import ParseError
 from .structures import EMPTY_PARAMETERSET_OPTION
@@ -130,7 +129,7 @@ def pytest_cmdline_main(config: Config) -> Optional[Union[int, ExitCode]]:
     return None
 
 
-@attr.s(slots=True, auto_attribs=True)
+@dataclasses.dataclass
 class KeywordMatcher:
     """A matcher for keywords.
 
@@ -145,6 +144,8 @@ class KeywordMatcher:
     any item, as well as names directly assigned to test functions.
     """
 
+    __slots__ = ("_names",)
+
     _names: AbstractSet[str]
 
     @classmethod
@@ -201,13 +202,15 @@ def deselect_by_keyword(items: "List[Item]", config: Config) -> None:
         items[:] = remaining
 
 
-@attr.s(slots=True, auto_attribs=True)
+@dataclasses.dataclass
 class MarkMatcher:
     """A matcher for markers which are present.
 
     Tries to match on any marker names, attached to the given colitem.
     """
 
+    __slots__ = ("own_mark_names",)
+
     own_mark_names: AbstractSet[str]
 
     @classmethod

src/_pytest/mark/expression.py

@@ -15,6 +15,7 @@ The semantics are:
 - or/and/not evaluate according to the usual boolean semantics.
 """
 import ast
+import dataclasses
 import enum
 import re
 import types
@@ -25,8 +26,6 @@ from typing import NoReturn
 from typing import Optional
 from typing import Sequence
 
-import attr
-
 
 __all__ = [
     "Expression",
@@ -44,8 +43,9 @@ class TokenType(enum.Enum):
     EOF = "end of input"
 
 
-@attr.s(frozen=True, slots=True, auto_attribs=True)
+@dataclasses.dataclass(frozen=True)
 class Token:
+    __slots__ = ("type", "value", "pos")
     type: TokenType
     value: str
     pos: int

src/_pytest/mark/structures.py

@@ -1,4 +1,5 @@
 import collections.abc
+import dataclasses
 import inspect
 import warnings
 from typing import Any
@@ -20,8 +21,6 @@ from typing import TYPE_CHECKING
 from typing import TypeVar
 from typing import Union
 
-import attr
-
 from .._code import getfslineno
 from ..compat import ascii_escaped
 from ..compat import final
@@ -191,8 +190,10 @@ class ParameterSet(NamedTuple):
 
 
 @final
-@attr.s(frozen=True, init=False, auto_attribs=True)
+@dataclasses.dataclass(frozen=True)
 class Mark:
+    """A pytest mark."""
+
     #: Name of the mark.
     name: str
     #: Positional arguments of the mark decorator.
@@ -201,9 +202,11 @@ class Mark:
     kwargs: Mapping[str, Any]
 
     #: Source Mark for ids with parametrize Marks.
-    _param_ids_from: Optional["Mark"] = attr.ib(default=None, repr=False)
+    _param_ids_from: Optional["Mark"] = dataclasses.field(default=None, repr=False)
     #: Resolved/generated ids with parametrize Marks.
-    _param_ids_generated: Optional[Sequence[str]] = attr.ib(default=None, repr=False)
+    _param_ids_generated: Optional[Sequence[str]] = dataclasses.field(
+        default=None, repr=False
+    )
 
     def __init__(
         self,
@@ -261,7 +264,7 @@ class Mark:
 Markable = TypeVar("Markable", bound=Union[Callable[..., object], type])
 
 
-@attr.s(init=False, auto_attribs=True)
+@dataclasses.dataclass
 class MarkDecorator:
     """A decorator for applying a mark on test functions and classes.
 

src/_pytest/python.py

@@ -1,4 +1,5 @@
 """Python test discovery, setup and run of test functions."""
+import dataclasses
 import enum
 import fnmatch
 import inspect
@@ -27,8 +28,6 @@ from typing import Tuple
 from typing import TYPE_CHECKING
 from typing import Union
 
-import attr
-
 import _pytest
 from _pytest import fixtures
 from _pytest import nodes
@@ -956,10 +955,20 @@ def hasnew(obj: object) -> bool:
 
 
 @final
-@attr.s(frozen=True, auto_attribs=True, slots=True)
+@dataclasses.dataclass(frozen=True)
 class IdMaker:
     """Make IDs for a parametrization."""
 
+    __slots__ = (
+        "argnames",
+        "parametersets",
+        "idfn",
+        "ids",
+        "config",
+        "nodeid",
+        "func_name",
+    )
+
     # The argnames of the parametrization.
     argnames: Sequence[str]
     # The ParameterSets of the parametrization.
@@ -1109,7 +1118,7 @@ class IdMaker:
 
 
 @final
-@attr.s(frozen=True, slots=True, auto_attribs=True)
+@dataclasses.dataclass(frozen=True)
 class CallSpec2:
     """A planned parameterized invocation of a test function.
 
@@ -1120,18 +1129,18 @@ class CallSpec2:
 
     # arg name -> arg value which will be passed to the parametrized test
     # function (direct parameterization).
-    funcargs: Dict[str, object] = attr.Factory(dict)
+    funcargs: Dict[str, object] = dataclasses.field(default_factory=dict)
     # arg name -> arg value which will be passed to a fixture of the same name
     # (indirect parametrization).
-    params: Dict[str, object] = attr.Factory(dict)
+    params: Dict[str, object] = dataclasses.field(default_factory=dict)
     # arg name -> arg index.
-    indices: Dict[str, int] = attr.Factory(dict)
+    indices: Dict[str, int] = dataclasses.field(default_factory=dict)
     # Used for sorting parametrized resources.
-    _arg2scope: Dict[str, Scope] = attr.Factory(dict)
+    _arg2scope: Dict[str, Scope] = dataclasses.field(default_factory=dict)
     # Parts which will be added to the item's name in `[..]` separated by "-".
-    _idlist: List[str] = attr.Factory(list)
+    _idlist: List[str] = dataclasses.field(default_factory=list)
     # Marks which will be applied to the item.
-    marks: List[Mark] = attr.Factory(list)
+    marks: List[Mark] = dataclasses.field(default_factory=list)
 
     def setmulti(
         self,
@@ -1163,9 +1172,9 @@ class CallSpec2:
         return CallSpec2(
             funcargs=funcargs,
             params=params,
-            arg2scope=arg2scope,
             indices=indices,
-            idlist=[*self._idlist, id],
+            _arg2scope=arg2scope,
+            _idlist=[*self._idlist, id],
             marks=[*self.marks, *normalize_mark_list(marks)],
         )
 

src/_pytest/reports.py

@@ -1,3 +1,4 @@
+import dataclasses
 import os
 from io import StringIO
 from pprint import pprint
@@ -16,8 +17,6 @@ from typing import TYPE_CHECKING
 from typing import TypeVar
 from typing import Union
 
-import attr
-
 from _pytest._code.code import ExceptionChainRepr
 from _pytest._code.code import ExceptionInfo
 from _pytest._code.code import ExceptionRepr
@@ -459,15 +458,15 @@ def _report_to_json(report: BaseReport) -> Dict[str, Any]:
     def serialize_repr_entry(
         entry: Union[ReprEntry, ReprEntryNative]
     ) -> Dict[str, Any]:
-        data = attr.asdict(entry)
+        data = dataclasses.asdict(entry)
         for key, value in data.items():
             if hasattr(value, "__dict__"):
-                data[key] = attr.asdict(value)
+                data[key] = dataclasses.asdict(value)
         entry_data = {"type": type(entry).__name__, "data": data}
         return entry_data
 
     def serialize_repr_traceback(reprtraceback: ReprTraceback) -> Dict[str, Any]:
-        result = attr.asdict(reprtraceback)
+        result = dataclasses.asdict(reprtraceback)
         result["reprentries"] = [
             serialize_repr_entry(x) for x in reprtraceback.reprentries
         ]
@@ -477,7 +476,7 @@ def _report_to_json(report: BaseReport) -> Dict[str, Any]:
         reprcrash: Optional[ReprFileLocation],
     ) -> Optional[Dict[str, Any]]:
         if reprcrash is not None:
-            return attr.asdict(reprcrash)
+            return dataclasses.asdict(reprcrash)
         else:
             return None
 
@@ -594,7 +593,10 @@ def _report_kwargs_from_json(reportdict: Dict[str, Any]) -> Dict[str, Any]:
                 ExceptionChainRepr, ReprExceptionInfo
             ] = ExceptionChainRepr(chain)
         else:
-            exception_info = ReprExceptionInfo(reprtraceback, reprcrash)
+            exception_info = ReprExceptionInfo(
+                reprtraceback=reprtraceback,
+                reprcrash=reprcrash,
+            )
 
         for section in reportdict["longrepr"]["sections"]:
             exception_info.addsection(*section)

src/_pytest/runner.py

@@ -1,5 +1,6 @@
 """Basic collect and runtest protocol implementations."""
 import bdb
+import dataclasses
 import os
 import sys
 from typing import Callable
@@ -14,8 +15,6 @@ from typing import TYPE_CHECKING
 from typing import TypeVar
 from typing import Union
 
-import attr
-
 from .reports import BaseReport
 from .reports import CollectErrorRepr
 from .reports import CollectReport
@@ -268,7 +267,7 @@ TResult = TypeVar("TResult", covariant=True)
 
 
 @final
-@attr.s(repr=False, init=False, auto_attribs=True)
+@dataclasses.dataclass
 class CallInfo(Generic[TResult]):
     """Result/Exception info of a function invocation."""
 

src/_pytest/skipping.py

@@ -1,4 +1,5 @@
 """Support for skip/xfail functions and markers."""
+import dataclasses
 import os
 import platform
 import sys
@@ -9,8 +10,6 @@ from typing import Optional
 from typing import Tuple
 from typing import Type
 
-import attr
-
 from _pytest.config import Config
 from _pytest.config import hookimpl
 from _pytest.config.argparsing import Parser
@@ -157,7 +156,7 @@ def evaluate_condition(item: Item, mark: Mark, condition: object) -> Tuple[bool,
     return result, reason
 
 
-@attr.s(slots=True, frozen=True, auto_attribs=True)
+@dataclasses.dataclass(frozen=True)
 class Skip:
     """The result of evaluate_skip_marks()."""
 
@@ -192,10 +191,12 @@ def evaluate_skip_marks(item: Item) -> Optional[Skip]:
     return None
 
 
-@attr.s(slots=True, frozen=True, auto_attribs=True)
+@dataclasses.dataclass(frozen=True)
 class Xfail:
     """The result of evaluate_xfail_marks()."""
 
+    __slots__ = ("reason", "run", "strict", "raises")
+
     reason: str
     run: bool
     strict: bool

src/_pytest/terminal.py

@@ -3,6 +3,7 @@
 This is a good source for looking at the various reporting hooks.
 """
 import argparse
+import dataclasses
 import datetime
 import inspect
 import platform
@@ -27,7 +28,6 @@ from typing import Tuple
 from typing import TYPE_CHECKING
 from typing import Union
 
-import attr
 import pluggy
 
 import _pytest._version
@@ -287,7 +287,7 @@ def pytest_report_teststatus(report: BaseReport) -> Tuple[str, str, str]:
     return outcome, letter, outcome.upper()
 
 
-@attr.s(auto_attribs=True)
+@dataclasses.dataclass
 class WarningReport:
     """Simple structure to hold warnings information captured by ``pytest_warning_recorded``.
 

src/_pytest/tmpdir.py

@@ -1,10 +1,12 @@
 """Support for providing temporary directories to test functions."""
+import dataclasses
 import os
 import re
 import sys
 import tempfile
 from pathlib import Path
 from shutil import rmtree
+from typing import Any
 from typing import Dict
 from typing import Generator
 from typing import Optional
@@ -21,7 +23,6 @@ if TYPE_CHECKING:
     RetentionType = Literal["all", "failed", "none"]
 
 
-import attr
 from _pytest.config.argparsing import Parser
 
 from .pathlib import LOCK_TIMEOUT
@@ -42,18 +43,19 @@ tmppath_result_key = StashKey[Dict[str, bool]]()
 
 
 @final
-@attr.s(init=False)
+@dataclasses.dataclass
 class TempPathFactory:
     """Factory for temporary directories under the common base temp directory.
 
     The base directory can be configured using the ``--basetemp`` option.
     """
 
-    _given_basetemp = attr.ib(type=Optional[Path])
+    _given_basetemp: Optional[Path]
-    _trace = attr.ib()
+    # pluggy TagTracerSub, not currently exposed, so Any.
-    _basetemp = attr.ib(type=Optional[Path])
+    _trace: Any
-    _retention_count = attr.ib(type=int)
+    _basetemp: Optional[Path]
-    _retention_policy = attr.ib(type="RetentionType")
+    _retention_count: int
+    _retention_policy: "RetentionType"
 
     def __init__(
         self,

src/_pytest/warning_types.py

@@ -1,3 +1,4 @@
+import dataclasses
 import inspect
 import warnings
 from types import FunctionType
@@ -6,8 +7,6 @@ from typing import Generic
 from typing import Type
 from typing import TypeVar
 
-import attr
-
 from _pytest.compat import final
 
 
@@ -130,7 +129,7 @@ _W = TypeVar("_W", bound=PytestWarning)
 
 
 @final
-@attr.s(auto_attribs=True)
+@dataclasses.dataclass
 class UnformattedWarning(Generic[_W]):
     """A warning meant to be formatted during runtime.
 

testing/acceptance_test.py

@@ -1,9 +1,8 @@
+import dataclasses
 import os
 import sys
 import types
 
-import attr
-
 import pytest
 from _pytest.compat import importlib_metadata
 from _pytest.config import ExitCode
@@ -115,11 +114,11 @@ class TestGeneralUsage:
 
         loaded = []
 
-        @attr.s
+        @dataclasses.dataclass
         class DummyEntryPoint:
-            name = attr.ib()
+            name: str
-            module = attr.ib()
+            module: str
-            group = "pytest11"
+            group: str = "pytest11"
 
             def load(self):
                 __import__(self.module)
@@ -132,10 +131,10 @@ class TestGeneralUsage:
             DummyEntryPoint("mycov", "mycov_module"),
         ]
 
-        @attr.s
+        @dataclasses.dataclass
         class DummyDist:
-            entry_points = attr.ib()
+            entry_points: object
-            files = ()
+            files: object = ()
 
         def my_dists():
             return (DummyDist(entry_points),)
@@ -1037,14 +1036,14 @@ def test_fixture_values_leak(pytester: Pytester) -> None:
     """
     pytester.makepyfile(
         """
-        import attr
+        import dataclasses
         import gc
         import pytest
         import weakref
 
-        @attr.s
+        @dataclasses.dataclass
-        class SomeObj(object):
+        class SomeObj:
-            name = attr.ib()
+            name: str
 
         fix_of_test1_ref = None
         session_ref = None

testing/conftest.py

@@ -1,3 +1,4 @@
+import dataclasses
 import re
 import sys
 from typing import List
@@ -192,20 +193,18 @@ def mock_timing(monkeypatch: MonkeyPatch):
     Time is static, and only advances through `sleep` calls, thus tests might sleep over large
     numbers and obtain accurate time() calls at the end, making tests reliable and instant.
     """
-    import attr
 
-    @attr.s
+    @dataclasses.dataclass
     class MockTiming:
+        _current_time: float = 1590150050.0
 
-        _current_time = attr.ib(default=1590150050.0)
+        def sleep(self, seconds: float) -> None:
-
-        def sleep(self, seconds):
             self._current_time += seconds
 
-        def time(self):
+        def time(self) -> float:
             return self._current_time
 
-        def patch(self):
+        def patch(self) -> None:
             from _pytest import timing
 
             monkeypatch.setattr(timing, "sleep", self.sleep)

testing/python/metafunc.py

@@ -1,3 +1,4 @@
+import dataclasses
 import itertools
 import re
 import sys
@@ -12,7 +13,6 @@ from typing import Sequence
 from typing import Tuple
 from typing import Union
 
-import attr
 import hypothesis
 from hypothesis import strategies
 
@@ -39,14 +39,14 @@ class TestMetafunc:
             def __init__(self, names):
                 self.names_closure = names
 
-        @attr.s
+        @dataclasses.dataclass
         class DefinitionMock(python.FunctionDefinition):
-            obj = attr.ib()
+            _nodeid: str
-            _nodeid = attr.ib()
+            obj: object
 
         names = getfuncargnames(func)
         fixtureinfo: Any = FuncFixtureInfoMock(names)
-        definition: Any = DefinitionMock._create(func, "mock::nodeid")
+        definition: Any = DefinitionMock._create(obj=func, _nodeid="mock::nodeid")
         return python.Metafunc(definition, fixtureinfo, config, _ispytest=True)
 
     def test_no_funcargs(self) -> None:
@@ -140,9 +140,9 @@ class TestMetafunc:
         """Unit test for _find_parametrized_scope (#3941)."""
         from _pytest.python import _find_parametrized_scope
 
-        @attr.s
+        @dataclasses.dataclass
         class DummyFixtureDef:
-            _scope = attr.ib()
+            _scope: Scope
 
         fixtures_defs = cast(
             Dict[str, Sequence[fixtures.FixtureDef[object]]],

testing/test_config.py

@@ -1,3 +1,4 @@
+import dataclasses
 import os
 import re
 import sys
@@ -10,8 +11,6 @@ from typing import Tuple
 from typing import Type
 from typing import Union
 
-import attr
-
 import _pytest._code
 import pytest
 from _pytest.compat import importlib_metadata
@@ -423,11 +422,11 @@ class TestParseIni:
         This test installs a mock "myplugin-1.5" which is used in the parametrized test cases.
         """
 
-        @attr.s
+        @dataclasses.dataclass
         class DummyEntryPoint:
-            name = attr.ib()
+            name: str
-            module = attr.ib()
+            module: str
-            group = "pytest11"
+            group: str = "pytest11"
 
             def load(self):
                 __import__(self.module)
@@ -437,11 +436,11 @@ class TestParseIni:
             DummyEntryPoint("myplugin1", "myplugin1_module"),
         ]
 
-        @attr.s
+        @dataclasses.dataclass
         class DummyDist:
-            entry_points = attr.ib()
+            entry_points: object
-            files = ()
+            files: object = ()
-            version = plugin_version
+            version: str = plugin_version
 
             @property
             def metadata(self):

testing/test_pathlib.py

@@ -518,10 +518,10 @@ class TestImportLibMode:
         fn1.write_text(
             dedent(
                 """
-                import attr
+                import dataclasses
                 import pickle
 
-                @attr.s(auto_attribs=True)
+                @dataclasses.dataclass
                 class Data:
                     x: int = 42
                 """
@@ -533,10 +533,10 @@ class TestImportLibMode:
         fn2.write_text(
             dedent(
                 """
-                import attr
+                import dataclasses
                 import pickle
 
-                @attr.s(auto_attribs=True)
+                @dataclasses.dataclass
                 class Data:
                     x: str = ""
                 """

testing/test_tmpdir.py

@@ -1,3 +1,4 @@
+import dataclasses
 import os
 import stat
 import sys
@@ -6,8 +7,7 @@ from pathlib import Path
 from typing import Callable
 from typing import cast
 from typing import List
-
+from typing import Union
-import attr
 
 import pytest
 from _pytest import pathlib
@@ -31,9 +31,9 @@ def test_tmp_path_fixture(pytester: Pytester) -> None:
     results.stdout.fnmatch_lines(["*1 passed*"])
 
 
-@attr.s
+@dataclasses.dataclass
 class FakeConfig:
-    basetemp = attr.ib()
+    basetemp: Union[str, Path]
 
     @property
     def trace(self):
@@ -56,7 +56,7 @@ class FakeConfig:
 
 
 class TestTmpPathHandler:
-    def test_mktemp(self, tmp_path):
+    def test_mktemp(self, tmp_path: Path) -> None:
         config = cast(Config, FakeConfig(tmp_path))
         t = TempPathFactory.from_config(config, _ispytest=True)
         tmp = t.mktemp("world")
@@ -67,7 +67,9 @@ class TestTmpPathHandler:
         assert str(tmp2.relative_to(t.getbasetemp())).startswith("this")
         assert tmp2 != tmp
 
-    def test_tmppath_relative_basetemp_absolute(self, tmp_path, monkeypatch):
+    def test_tmppath_relative_basetemp_absolute(
+        self, tmp_path: Path, monkeypatch: MonkeyPatch
+    ) -> None:
         """#4425"""
         monkeypatch.chdir(tmp_path)
         config = cast(Config, FakeConfig("hello"))