mechanical-refactor-verify

1import json2import sys3from pathlib import Path4 5sys.path.insert(0, str(Path(__file__).resolve().parents[2]))6 7from cli_testlib import _chain, _write_stub_proof8from mechanical_refactor_reproduction_cli import (9    VERDICT_FAIL,10    VERDICT_PASS,11    main,12    render_report,13    verify_chain,14)15 16_MSG = "mechanical_provable: move foo"17 18 19def _counting_proof(script: Path, counter: Path, *, passing: bool = True) -> None:20    """Make the stub proof bump a run counter so re-execution is observable."""21    verdict = (22        'print("PASS: reproduces the commit byte-for-byte.")\nsys.exit(0)\n'23        if passing24        else 'print("RESIDUAL (1 lines):\\n+x")\nsys.exit(1)\n'25    )26    script.write_text(27        "import sys\n"28        f"counter = __import__('pathlib').Path({str(counter)!r})\n"29        "runs = int(counter.read_text()) if counter.exists() else 0\n"30        "counter.write_text(str(runs + 1))\n" + verdict31    )32 33 34def _cache_file(repo: Path) -> Path:35    return repo / ".git" / "mechanical_refactor_passed_proofs.json"36 37 38def test_skip_passed_reuses_an_unchanged_pass_without_rerunning(39    repo: Path, tmp_path: Path40) -> None:41    """A PASS recorded on the first run is reused: the proof does not execute again."""42    proof = tmp_path / "proof"43    counter = tmp_path / "runs"44    base, shas = _chain(repo, [_MSG])45    _counting_proof(_write_stub_proof(proof, shas[0]), counter)46    args = dict(base=base, branch="chain", proof=proof, repo_root=str(repo))47 48    first = verify_chain(**args)49    assert first.verdicts[0].verdict == VERDICT_PASS50    assert counter.read_text() == "1"51 52    second = verify_chain(**args, skip_passed=True)53    assert second.verdicts[0].verdict == VERDICT_PASS54    assert second.verdicts[0].cached55    assert counter.read_text() == "1"56    assert second.passed57 58 59def test_without_the_flag_the_proof_always_reruns(repo: Path, tmp_path: Path) -> None:60    """The cache is recorded on every run but consulted only under skip_passed."""61    proof = tmp_path / "proof"62    counter = tmp_path / "runs"63    base, shas = _chain(repo, [_MSG])64    _counting_proof(_write_stub_proof(proof, shas[0]), counter)65    args = dict(base=base, branch="chain", proof=proof, repo_root=str(repo))66 67    verify_chain(**args)68    result = verify_chain(**args)69 70    assert counter.read_text() == "2"71    assert not result.verdicts[0].cached72 73 74def test_editing_the_proof_script_invalidates_the_cache(75    repo: Path, tmp_path: Path76) -> None:77    """A changed script hash misses the cache, so the edited (failing) proof reruns."""78    proof = tmp_path / "proof"79    base, shas = _chain(repo, [_MSG])80    script = _write_stub_proof(proof, shas[0])81 82    verify_chain(base=base, branch="chain", proof=proof, repo_root=str(repo))83    script.write_text('print("RESIDUAL (1 lines):\\n+x")\nraise SystemExit(1)\n')84    result = verify_chain(85        base=base, branch="chain", proof=proof, repo_root=str(repo), skip_passed=True86    )87 88    assert result.verdicts[0].verdict == VERDICT_FAIL89 90 91def test_editing_the_utils_copy_invalidates_the_cache(92    repo: Path, tmp_path: Path93) -> None:94    """The utils module next to the scripts is part of the key: editing it forces a rerun."""95    proof = tmp_path / "proof"96    counter = tmp_path / "runs"97    utils = proof / "mechanical_refactor_reproduction_utils.py"98    base, shas = _chain(repo, [_MSG])99    _counting_proof(_write_stub_proof(proof, shas[0]), counter)100    utils.parent.mkdir(parents=True, exist_ok=True)101    utils.write_text("ENGINE = 1\n")102    args = dict(base=base, branch="chain", proof=proof, repo_root=str(repo))103 104    verify_chain(**args)105    utils.write_text("ENGINE = 2\n")106    result = verify_chain(**args, skip_passed=True)107 108    assert counter.read_text() == "2"109    assert not result.verdicts[0].cached110 111 112def test_a_fail_is_never_recorded_in_the_cache(repo: Path, tmp_path: Path) -> None:113    """Only PASS verdicts enter the cache; a failing proof leaves no entry for its sha."""114    proof = tmp_path / "proof"115    base, shas = _chain(repo, [_MSG])116    _write_stub_proof(proof, shas[0], passing=False)117 118    verify_chain(base=base, branch="chain", proof=proof, repo_root=str(repo))119 120    cache = _cache_file(repo)121    assert not cache.exists() or shas[0] not in json.loads(cache.read_text())["passed"]122 123 124def test_corrupt_cache_file_is_treated_as_empty(repo: Path, tmp_path: Path) -> None:125    """A garbage cache file never crashes the walk; the proof simply runs."""126    proof = tmp_path / "proof"127    base, shas = _chain(repo, [_MSG])128    _write_stub_proof(proof, shas[0])129    _cache_file(repo).write_text("{not json")130 131    result = verify_chain(132        base=base, branch="chain", proof=proof, repo_root=str(repo), skip_passed=True133    )134 135    assert result.verdicts[0].verdict == VERDICT_PASS136    assert not result.verdicts[0].cached137 138 139def test_cache_lives_in_the_git_common_dir_and_records_the_pass(140    repo: Path, tmp_path: Path141) -> None:142    """A PASS writes the (sha, script hash, utils hash) entry under .git/."""143    proof = tmp_path / "proof"144    base, shas = _chain(repo, [_MSG])145    _write_stub_proof(proof, shas[0])146 147    verify_chain(base=base, branch="chain", proof=proof, repo_root=str(repo))148 149    entry = json.loads(_cache_file(repo).read_text())["passed"][shas[0]]150    assert set(entry) == {"script_sha256", "utils_sha256"}151    assert len(entry["script_sha256"]) == 64152 153 154def test_report_counts_reused_proofs_and_main_accepts_the_flag(155    repo: Path, tmp_path: Path156) -> None:157    """The report carries the reused count and --skip-passed works through main."""158    proof = tmp_path / "proof"159    base, shas = _chain(repo, [_MSG])160    _write_stub_proof(proof, shas[0])161    cli_args = [162        "--base",163        base,164        "--branch",165        "chain",166        "--proof",167        str(proof),168        "--repo-root",169        str(repo),170    ]171 172    assert main(cli_args) == 0173    result = verify_chain(174        base=base, branch="chain", proof=proof, repo_root=str(repo), skip_passed=True175    )176    report = render_report(result)177 178    assert "reused from the passed-proof cache (--skip-passed): 1" in report179    assert main([*cli_args, "--skip-passed"]) == 0180