from pathlib import Path
import runpy
import tempfile
import unittest


APPROVE = runpy.run_path(str(Path(__file__).resolve().parents[1] / "scripts/nq-approve-merge"))
HEAD = "a" * 40


class MergeGateTests(unittest.TestCase):
    def test_review_evidence_must_match_exact_head_and_approval(self):
        root = Path("/tmp/opencode")
        root.mkdir(exist_ok=True)
        with tempfile.TemporaryDirectory(dir=root) as directory:
            review = Path(directory) / "review.txt"
            review.write_text(f"Findings: none\nREVIEWED_HEAD: {HEAD}\nREVIEW_VERDICT: APPROVED\n")
            APPROVE["validate_review"](review, HEAD)
            with self.assertRaisesRegex(RuntimeError, "exact head"):
                APPROVE["validate_review"](review, "b" * 40)
            review.write_text(f"REVIEWED_HEAD: {HEAD}\nREVIEW_VERDICT: CHANGES_REQUIRED\n")
            with self.assertRaisesRegex(RuntimeError, "exact head"):
                APPROVE["validate_review"](review, HEAD)


if __name__ == "__main__":
    unittest.main()