fix some ruff warnings in tests files

tests/e2e/test_cli_version.py

@@ -1,6 +1,8 @@
+from click.testing import CliRunner
+
 from mutmut import __version__
 from mutmut.__main__ import cli
-from click.testing import CliRunner
+
 
 def test_cli_version():
     result = CliRunner().invoke(cli, ["--version"])

tests/e2e/test_e2e_result_snapshots.py

@@ -1,16 +1,17 @@
-from contextlib import contextmanager
 import json
 import os
-from pathlib import Path
 import shutil
+from contextlib import contextmanager
+from pathlib import Path
 from typing import Any
+
 import mutmut
-from mutmut.__main__ import _run, walk_source_files, SourceFileMutationData, ensure_config_loaded
+from mutmut.__main__ import SourceFileMutationData, _run, ensure_config_loaded, walk_source_files
 
 
 @contextmanager
 def change_cwd(path):
-    old_cwd = os.path.abspath(os.getcwd())
+    old_cwd = Path(Path.cwd()).resolve()
     os.chdir(path)
     try:
         yield
@@ -25,7 +26,7 @@ def read_all_stats_for_project(project_path: Path) -> dict[str, dict]:
 
         stats = {}
         for p in walk_source_files():
-            if mutmut.config.should_ignore_for_mutation(p): # type: ignore
+            if mutmut.config.should_ignore_for_mutation(p):  # type: ignore
                 continue
             data = SourceFileMutationData(path=p)
             data.load()

tests/test_generation_error_handling.py

@@ -1,17 +1,20 @@
 from pathlib import Path
-from mutmut.__main__ import create_mutants, Config, InvalidGeneratedSyntaxException
-import mutmut.__main__
-import mutmut
+
 import pytest
-import os
+
+import mutmut
+import mutmut.__main__
+from mutmut.__main__ import InvalidGeneratedSyntaxException, create_mutants
 
 source_dir = Path(__file__).parent / 'data' / 'test_generation'
-source_dir = source_dir.relative_to(os.getcwd())
+source_dir = source_dir.relative_to(Path.cwd())
+
 
 class MockConfig:
     def should_ignore_for_mutation(self, path: Path) -> bool:
         return False
 
+
 def test_mutant_generation_raises_exception_on_invalid_syntax(monkeypatch):
     mutmut._reset_globals()
     mutmut.config = MockConfig()

tests/test_mutation.py

@@ -1,29 +1,29 @@
 import os
 from unittest.mock import Mock, patch
-import pytest
+
 import libcst as cst
+import pytest
 
 import mutmut
 from mutmut.__main__ import (
     CLASS_NAME_SEPARATOR,
+    CatchOutput,
+    MutmutProgrammaticFailException,
     get_diff_for_mutant,
     orig_function_and_class_names_from_key,
     run_forced_fail_test,
-    Config,
-    MutmutProgrammaticFailException,
-    CatchOutput,
 )
-from mutmut.trampoline_templates import trampoline_impl, mangle_function_name
 from mutmut.file_mutation import create_mutations, mutate_file_contents
+from mutmut.trampoline_templates import mangle_function_name, trampoline_impl
+
 
 def mutants_for_source(source: str) -> list[str]:
     module, mutated_nodes = create_mutations(source)
-    mutants: list[str] = []
-    for m in mutated_nodes:
-        mutants.append(module.deep_replace(m.original_node, m.mutated_node).code)  # type: ignore
+    mutants: list[str] = [module.deep_replace(m.original_node, m.mutated_node).code for m in mutated_nodes]  # type: ignore
 
     return mutants
 
+
 def mutated_module(source: str) -> str:
     mutated_code, _ = mutate_file_contents('', source)
     return mutated_code
@@ -220,7 +220,6 @@ def mutated_module(source: str) -> str:
         ('foo.bar', []),
         ('for x in y: pass', []),
         ('def foo(a, *args, **kwargs): pass', []),
-        ('import foo', []),
         ('isinstance(a, b)', []),
         ('len(a)', []),
         ('deepcopy(obj)', ['copy(obj)', 'deepcopy(None)']),
@@ -248,6 +247,7 @@ def foo() -> int:
 
     assert not mutants
 
+
 def test_do_not_mutate_specific_functions():
     source = """
 class A:
@@ -267,6 +267,7 @@ def __setattr__():
 
     assert not mutants
 
+
 def test_match_case():
     source = """
 match x:
@@ -285,6 +286,7 @@ def test_match_case():
 
     assert sorted(mutants) == sorted(expected)
 
+
 def test_mach_case_does_not_mutate_bitor():
     source = """
 def concat():
@@ -344,6 +346,7 @@ def test_pragma_no_mutate_and_no_cover():
     mutants = mutants_for_source(source)
     assert not mutants
 
+
 def test_pragma_no_mutate_on_function_definition():
     source = """
 def foo(): # pragma: no mutate
@@ -438,7 +441,8 @@ def foo():
 
 
 def test_orig_function_name_from_key():
-    assert orig_function_and_class_names_from_key(f'_{CLASS_NAME_SEPARATOR}Foo{CLASS_NAME_SEPARATOR}bar__mutmut_1') == ('bar', 'Foo')
+    assert orig_function_and_class_names_from_key(
+        f'_{CLASS_NAME_SEPARATOR}Foo{CLASS_NAME_SEPARATOR}bar__mutmut_1') == ('bar', 'Foo')
     assert orig_function_and_class_names_from_key('x_bar__mutmut_1') == ('bar', None)
 
 
@@ -496,6 +500,7 @@ def foo():
     assert mutated_source.split('\n')[0] == 'from __future__ import annotations'
     assert mutated_source.count('from __future__') == 1
 
+
 def test_from_future_with_docstring_still_first():
     source = """
 '''This documents the module'''
@@ -527,7 +532,7 @@ def test_run_forced_fail_test_with_failing_test(_start, _stop, _dump_output, cap
     print(f"out: {out}")
     print(f"err: {err}")
     assert 'done' in out
-    assert os.environ['MUTANT_UNDER_TEST'] is ''
+    assert not os.environ['MUTANT_UNDER_TEST']
 
 
 # Negate the effects of CatchOutput because it does not play nicely with capfd in GitHub Actions
@@ -540,9 +545,9 @@ def test_run_forced_fail_test_with_mutmut_programmatic_fail_exception(_start, _s
 
     run_forced_fail_test(runner)
 
-    out, err = capfd.readouterr()
+    out, _ = capfd.readouterr()
     assert 'done' in out
-    assert os.environ['MUTANT_UNDER_TEST'] is ''
+    assert not os.environ['MUTANT_UNDER_TEST']
 
 
 # Negate the effects of CatchOutput because it does not play nicely with capfd in GitHub Actions
@@ -556,8 +561,8 @@ def test_run_forced_fail_test_with_all_tests_passing(_start, _stop, _dump_output
     with pytest.raises(SystemExit) as error:
         run_forced_fail_test(runner)
 
-    assert error.value.code is 1
-    out, err = capfd.readouterr()
+    assert error.value.code == 1
+    out, _ = capfd.readouterr()
     assert 'FAILED: Unable to force test failures' in out
 
 
@@ -569,6 +574,7 @@ def _mocked_runner_run_forced_failed(return_value=None, side_effect=None):
     )
     return runner
 
+
 def test_do_not_mutate_top_level_decorators():
     # Modifying top-level decorators could influence all mutations
     # because they are executed at import time
@@ -591,6 +597,7 @@ def x(self):
 
     assert not mutants
 
+
 # TODO: implement removal of inner decorators
 @pytest.mark.skip
 def test_decorated_inner_functions_mutation():

tests/test_mutmut3.py

@@ -1,5 +1,6 @@
-from mutmut.trampoline_templates import trampoline_impl
 from mutmut.file_mutation import mutate_file_contents
+from mutmut.trampoline_templates import trampoline_impl
+
 
 def mutated_module(source: str) -> str:
     mutated_code, _ = mutate_file_contents('', source)