test: add Gate 3 numerical oracle contracts

tests/test_quality_gate_scripts.py

@@ -3,9 +3,11 @@
 from __future__ import annotations
 
 import json
+from pathlib import Path
 from types import SimpleNamespace
 
 from scripts import check_mutation_score
+from scripts import check_mutation_targets
 from scripts import run_repeat_gate
 
 
@@ -17,6 +19,13 @@ def test_mutation_score_accepts_exact_floor_and_rejects_regression():
     ]
 
 
+def test_mutation_score_validator_default_matches_immutable_policy_floor():
+    parser = check_mutation_score._parser()
+
+    assert check_mutation_score.DEFAULT_MUTATION_SCORE_MINIMUM == 85.0
+    assert parser.parse_args(["stats.json"]).minimum == 85.0
+
+
 def test_mutation_score_rejects_malformed_and_interrupted_runs():
     assert check_mutation_score.validate_mutation_stats(
         {"killed": True, "total": 1}, minimum=70,
@@ -26,6 +35,74 @@ def test_mutation_score_rejects_malformed_and_interrupted_runs():
     ) == ["mutation run was interrupted"]
 
 
+def test_mutation_target_guard_invalidates_stale_copied_targets(tmp_path):
+    pyproject = tmp_path / "pyproject.toml"
+    pyproject.write_text(
+        """
+[tool.mutmut]
+only_mutate = [
+    "obliteratus/config.py",
+    "obliteratus/analysis/whitened_svd.py",
+]
+required_mutation_targets = [
+    "obliteratus/analysis/whitened_svd.py",
+]
+""".lstrip(),
+        encoding="utf-8",
+    )
+    for target in (
+        "obliteratus/config.py",
+        "obliteratus/analysis/whitened_svd.py",
+    ):
+        source = tmp_path / target
+        source.parent.mkdir(parents=True, exist_ok=True)
+        source.write_text("pass\n", encoding="utf-8")
+
+    valid_meta = tmp_path / "mutants/obliteratus/config.py.meta"
+    valid_meta.parent.mkdir(parents=True, exist_ok=True)
+    valid_meta.write_text('{"exit_code_by_key": {"obliteratus.config.x__mutmut_1": null}}')
+
+    stale_copy = tmp_path / "mutants/obliteratus/analysis/whitened_svd.py"
+    stale_copy.parent.mkdir(parents=True, exist_ok=True)
+    stale_copy.write_text("pass\n", encoding="utf-8")
+
+    stale = check_mutation_targets.prepare_required_targets(pyproject)
+
+    assert stale == [Path("obliteratus/analysis/whitened_svd.py")]
+    assert not stale_copy.exists()
+    assert check_mutation_targets.validate_required_targets(pyproject) == [
+        "configured mutation target produced zero mutants: obliteratus/analysis/whitened_svd.py",
+    ]
+
+
+def test_mutation_target_guard_passes_when_each_exact_target_has_mutants(tmp_path):
+    pyproject = tmp_path / "pyproject.toml"
+    pyproject.write_text(
+        """
+[tool.mutmut]
+only_mutate = [
+    "obliteratus/analysis/*.py",
+    "obliteratus/analysis/numerical_contracts.py",
+]
+required_mutation_targets = [
+    "obliteratus/analysis/numerical_contracts.py",
+]
+""".lstrip(),
+        encoding="utf-8",
+    )
+    source = tmp_path / "obliteratus/analysis/numerical_contracts.py"
+    source.parent.mkdir(parents=True, exist_ok=True)
+    source.write_text("pass\n", encoding="utf-8")
+    meta = tmp_path / "mutants/obliteratus/analysis/numerical_contracts.py.meta"
+    meta.parent.mkdir(parents=True, exist_ok=True)
+    meta.write_text(
+        '{"exit_code_by_key": {"obliteratus.analysis.numerical_contracts.x__mutmut_1": null}}',
+        encoding="utf-8",
+    )
+
+    assert check_mutation_targets.validate_required_targets(pyproject) == []
+
+
 def test_repeat_orders_are_distinct_and_deterministic():
     paths = ["a", "b", "c", "d"]
     assert run_repeat_gate.test_orders(paths) == [