SIM119: Removed due to false-positives (#123)

See https://github.com/MartinThoma/flake8-scream/pull/1/files Closes #63
MartinThoma · Mar 28, 2022 · 91f371f · 91f371f
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diff --git a/README.md b/README.md
@@ -46,7 +46,7 @@ Python-specific rules:
 * [`SIM115`](https://github.com/MartinThoma/flake8-simplify/issues/17): Use context handler for opening files ([example](#SIM115))
 * [`SIM116`](https://github.com/MartinThoma/flake8-simplify/issues/31): Use a dictionary instead of many if/else equality checks ([example](#SIM116))
 * [`SIM117`](https://github.com/MartinThoma/flake8-simplify/issues/35): Merge with-statements that use the same scope ([example](#SIM117))
-* [`SIM119`](https://github.com/MartinThoma/flake8-simplify/issues/37) ![](https://shields.io/badge/-legacyfix-inactive): Use dataclasses for data containers ([example](#SIM119))
+* `SIM119`: ![](https://img.shields.io/badge/-removed-lightgrey) Moved to [flake8-scream](https://github.com/MartinThoma/flake8-scream) due to [issue 63](https://github.com/MartinThoma/flake8-simplify/issues/63)
 * `SIM120` ![](https://shields.io/badge/-legacyfix-inactive): Use 'class FooBar:' instead of 'class FooBar(object):' ([example](#SIM120))
 * `SIM121`: Reserved for [SIM908](#sim908) once it's stable
 * `SIM124`: Reserved for [SIM904](#sim904) once it's stable
@@ -340,22 +340,6 @@ key in a_dict
 
 Thank you for pointing this one out, [Aaron Gokaslan](https://github.com/Skylion007)!
 
-### SIM119
-
-Dataclasses were introduced with [PEP 557](https://www.python.org/dev/peps/pep-0557/)
-in Python 3.7. The main reason not to use dataclasses is to support legacy Python versions.
-
-Dataclasses create a lot of the boilerplate code for you:
-
-* `__init__`
-* `__eq__`
-* `__hash__`
-* `__str__`
-* `__repr__`
-
-A lot of projects use them:
-
-* [black](https://github.com/psf/black/blob/master/src/black/__init__.py#L1472)
 
 ### SIM120
 

diff --git a/flake8_simplify/__init__.py b/flake8_simplify/__init__.py
@@ -22,7 +22,7 @@
     get_sim905,
     get_sim906,
 )
-from flake8_simplify.rules.ast_classdef import get_sim119, get_sim120
+from flake8_simplify.rules.ast_classdef import get_sim120
 from flake8_simplify.rules.ast_compare import get_sim118, get_sim300
 from flake8_simplify.rules.ast_expr import get_sim112
 from flake8_simplify.rules.ast_for import (
@@ -142,7 +142,6 @@ def visit_Compare(self, node: ast.Compare) -> None:
         self.generic_visit(node)
 
     def visit_ClassDef(self, node: ast.ClassDef) -> None:
-        self.errors += get_sim119(node)
         self.errors += get_sim120(node)
         self.generic_visit(node)
 

diff --git a/flake8_simplify/rules/ast_classdef.py b/flake8_simplify/rules/ast_classdef.py
@@ -3,88 +3,6 @@
 from typing import List, Tuple
 
 
-def get_sim119(node: ast.ClassDef) -> List[Tuple[int, int, str]]:
-    """
-    Get a list of all classes that should be dataclasses"
-
-        ClassDef(
-            name='Person',
-            bases=[],
-            keywords=[],
-            body=[
-                AnnAssign(
-                    target=Name(id='first_name', ctx=Store()),
-                    annotation=Name(id='str', ctx=Load()),
-                    value=None,
-                    simple=1,
-                ),
-                AnnAssign(
-                    target=Name(id='last_name', ctx=Store()),
-                    annotation=Name(id='str', ctx=Load()),
-                    value=None,
-                    simple=1,
-                ),
-                AnnAssign(
-                    target=Name(id='birthdate', ctx=Store()),
-                    annotation=Name(id='date', ctx=Load()),
-                    value=None,
-                    simple=1,
-                ),
-            ],
-            decorator_list=[Name(id='dataclass', ctx=Load())],
-        )
-    """
-    RULE = "SIM119 Use a dataclass for 'class {classname}'"
-    errors: List[Tuple[int, int, str]] = []
-
-    if not (len(node.decorator_list) == 0 and len(node.bases) == 0):
-        return errors
-
-    dataclass_functions = [
-        "__init__",
-        "__eq__",
-        "__hash__",
-        "__repr__",
-        "__str__",
-    ]
-    has_only_dataclass_functions = True
-    has_any_functions = False
-    has_complex_statements = False
-    for body_el in node.body:
-        if isinstance(body_el, (ast.FunctionDef, ast.AsyncFunctionDef)):
-            has_any_functions = True
-            if body_el.name == "__init__":
-                # Ensure constructor only has pure assignments
-                # without any calculation.
-                for el in body_el.body:
-                    if not isinstance(el, ast.Assign):
-                        has_complex_statements = True
-                        break
-                    # It is an assignment, but we only allow
-                    # `self.attribute = name`.
-                    if any(
-                        [
-                            not isinstance(target, ast.Attribute)
-                            for target in el.targets
-                        ]
-                    ) or not isinstance(el.value, ast.Name):
-                        has_complex_statements = True
-                        break
-            if body_el.name not in dataclass_functions:
-                has_only_dataclass_functions = False
-
-    if (
-        has_any_functions
-        and has_only_dataclass_functions
-        and not has_complex_statements
-    ):
-        errors.append(
-            (node.lineno, node.col_offset, RULE.format(classname=node.name))
-        )
-
-    return errors
-
-
 def get_sim120(node: ast.ClassDef) -> List[Tuple[int, int, str]]:
     """
     Get a list of all classes that inherit from object.

diff --git a/tests/test_100_rules.py b/tests/test_100_rules.py
@@ -493,104 +493,6 @@ def test_sim118_del_key():
     assert results == set()
 
 
-def test_sim119():
-    results = _results(
-        """
-class FooBar:
-    def __init__(self, a, b):
-        self.a = a
-        self.b = b
-"""
-    )
-    assert results == {"2:0 SIM119 Use a dataclass for 'class FooBar'"}
-
-
-def test_sim119_ignored_dunder_methods():
-    """
-    Dunder methods do not make a class not be a dataclass candidate.
-    Examples for dunder (double underscore) methods are:
-      * __str__
-      * __eq__
-      * __hash__
-    """
-    results = _results(
-        """
-class FooBar:
-    def __init__(self, a, b):
-        self.a = a
-        self.b = b
-
-    def __str__(self):
-        return "FooBar"
-"""
-    )
-    assert results == {"2:0 SIM119 Use a dataclass for 'class FooBar'"}
-
-
-@pytest.mark.xfail(
-    reason="https://github.com/MartinThoma/flake8-simplify/issues/63"
-)
-def test_sim119_false_positive():
-    results = _results(
-        '''class OfType:
-    """
-    >>> 3 == OfType(int, str, bool)
-    True
-    >>> 'txt' == OfType(int)
-    False
-    """
-
-    def __init__(self, *types):
-        self.types = types
-
-    def __eq__(self, other):
-        return isinstance(other, self.types)'''
-    )
-    for el in results:
-        assert "SIM119" not in el
-
-
-def test_sim119_async():
-    results = _results(
-        """
-class FooBar:
-    def __init__(self, a, b):
-        self.a = a
-        self.b = b
-
-    async def foo(self):
-        return "FooBar"
-"""
-    )
-    assert results == set()
-
-
-def test_sim119_constructor_processing():
-    results = _results(
-        """
-class FooBar:
-    def __init__(self, a):
-        self.a = a + 5
-"""
-    )
-    assert results == set()
-
-
-def test_sim119_pydantic():
-    results = _results(
-        """
-from pydantic import BaseModel
-
-class FooBar(BaseModel):
-    foo : str
-
-    class Config:
-        extra = "allow"
-"""
-    )
-    assert results == set()
-
-
 def test_sim120():
     results = _results("class FooBar(object): pass")
     assert results == {