mechanical-refactor-verify

1import subprocess2import sys3from pathlib import Path4 5import pytest6 7sys.path.insert(0, str(Path(__file__).resolve().parents[2]))8 9import mechanical_refactor_reproduction_utils as rr10from mechanical_refactor_reproduction_utils import (11    Repro,12    _def_span,13    _find_class,14    _find_def,15    _replace_span,16    _slice_span,17    dedent,18    exec_command,19    git_add_and_commit,20    verify_mechanical_refactor,21)22from reproduction_testlib import _apply, _commit, _git, _write  # noqa: F40123 24# --- extract_to_new_module -----------------------------------------------------25 26 27def test_extract_to_new_module_cuts_trailing_block(tmp_path: Path) -> None:28    """Cuts the trailing scaffolding+def block into a new file, prepending the future import."""29    (tmp_path / "src.py").write_text(30        "class M:\n"31        "    def keep(self):\n"32        "        return 1\n"33        "\n"34        "\n"35        "import logging\n"36        "\n"37        "logger = logging.getLogger(__name__)\n"38        "\n"39        "\n"40        "def foo(x):\n"41        "    return x + 1\n"42    )43    r = Repro("b", "t").extract_to_new_module(44        "src.py", "new.py", symbols=["foo"], future_import=True45    )46    _apply(r, tmp_path)47    assert (tmp_path / "src.py").read_text() == (48        "class M:\n    def keep(self):\n        return 1\n\n\n"49    )50    assert (tmp_path / "new.py").read_text() == (51        "from __future__ import annotations\n"52        "import logging\n"53        "\n"54        "logger = logging.getLogger(__name__)\n"55        "\n"56        "\n"57        "def foo(x):\n"58        "    return x + 1\n"59    )60 61 62def test_extract_to_new_module_carries_a_trailing_class(tmp_path: Path) -> None:63    """A class in the staged tail (not just a def) travels with the cut block."""64    (tmp_path / "src.py").write_text(65        "class M:\n"66        "    pass\n"67        "\n"68        "\n"69        "from dataclasses import dataclass\n"70        "\n"71        "\n"72        "@dataclass\n"73        "class Cfg:\n"74        "    x: int\n"75        "\n"76        "\n"77        "def foo():\n"78        "    return Cfg(1)\n"79    )80    r = Repro("b", "t").extract_to_new_module(81        "src.py", "new.py", symbols=["Cfg", "foo"], future_import=False82    )83    _apply(r, tmp_path)84    assert (tmp_path / "src.py").read_text() == "class M:\n    pass\n\n\n"85    assert "class Cfg:" in (tmp_path / "new.py").read_text()86    assert "def foo():" in (tmp_path / "new.py").read_text()87 88 89# --- extract_symbols_to_new_module ---------------------------------------------90 91 92# --- adversarial audit: module extraction ----------------------------------------93 94 95def test_extract_to_new_module_asserts_when_symbol_not_in_the_tail(96    tmp_path: Path,97) -> None:98    """A wanted symbol above a non-scaffolding statement is not in the tail and raises."""99    (tmp_path / "src.py").write_text(100        "def wanted():\n    return 1\n\n\nprint('side effect')\n"101    )102    r = Repro("b", "t").extract_to_new_module("src.py", "n.py", symbols=["wanted"])103    with pytest.raises(AssertionError):104        _apply(r, tmp_path)105 106 107def test_extract_to_new_module_refuses_a_trailing_main_guard(tmp_path: Path) -> None:108    """A trailing __main__ guard is executable code, not scaffolding: the tail cut raises."""109    (tmp_path / "src.py").write_text(110        "class Keep:\n"111        "    pass\n"112        "\n"113        "\n"114        "def foo():\n"115        "    return 1\n"116        "\n"117        "\n"118        'if __name__ == "__main__":\n'119        "    foo()\n"120    )121    r = Repro("b", "t").extract_to_new_module(122        "src.py", "new.py", symbols=["foo"], future_import=False123    )124    with pytest.raises(AssertionError):125        _apply(r, tmp_path)126    assert "__main__" in (tmp_path / "src.py").read_text()127