Drop attrs dependency, use dataclasses instead

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 Union
 from weakref import ref
 
-import attr
 import pluggy
 
 import _pytest
@@ -445,7 +445,7 @@ def recursionindex(self) -> Optional[int]:
 
 
 @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 @@ def getrepr(
         """
         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 @@ def match(self, regexp: Union[str, Pattern[str]]) -> "Literal[True]":
         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(
-        factory=dict, init=False, repr=False
+    astcache: Dict[Union[str, Path], ast.AST] = dataclasses.field(
+        default_factory=dict, init=False, repr=False
     )
 
     def _getindent(self, source: "Source") -> int:
@@ -978,7 +978,7 @@ def repr_excinfo(
         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 @@ def toterminal(self, tw: TerminalWriter) -> None:
 
 
 # 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"
-
-    def __attrs_post_init__(self) -> None:
-        self.sections: List[Tuple[str, str, str]] = []
+    reprcrash: Optional["ReprFileLocation"]
+    sections: List[Tuple[str, str, str]] = dataclasses.field(
+        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 @@ def toterminal(self, tw: TerminalWriter) -> None:
             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:
-        super().__attrs_post_init__()
+    def __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]
-        self.reprcrash = self.chain[-1][1]
+        super().__init__(
+            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 @@ def toterminal(self, tw: TerminalWriter) -> None:
         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 @@ def toterminal(self, tw: TerminalWriter) -> None:
         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 @@ def toterminal(self, tw: TerminalWriter) -> None:
 
 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 @@ def toterminal(self, tw: TerminalWriter) -> None:
         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 @@ def __str__(self) -> str:
         )
 
 
-@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 @@ def toterminal(self, tw: TerminalWriter) -> None:
         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 @@ def toterminal(self, tw: TerminalWriter, indent="") -> None:
             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 Set
 from typing import Union
 
-import attr
-
 from .pathlib import resolve_from_str
 from .pathlib import rm_rf
 from .reports import CollectReport
@@ -53,10 +52,12 @@
 
 
 @final
-@attr.s(init=False, auto_attribs=True)
+@dataclasses.dataclass
 class Cache:
-    _cachedir: Path = attr.ib(repr=False)
-    _config: Config = attr.ib(repr=False)
+    """Instance of the `cache` fixture."""
+
+    _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 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_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 InvocationParams:
             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.