diff --git a/tests/test_test_risk_map.py b/tests/test_test_risk_map.py
index e508246..34f8d7b 100644
--- a/tests/test_test_risk_map.py
+++ b/tests/test_test_risk_map.py
@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import json
+import sys
 from copy import deepcopy
 from pathlib import Path
 
@@ -28,7 +29,9 @@ def test_committed_test_risk_map_is_complete():
 def test_risk_map_rejects_duplicate_missing_and_unowned_modules(tmp_path):
     risk = json.loads((ROOT / "ci" / "test-risk-map.json").read_text())
     risk["owner"] = ""
-    duplicate = deepcopy(risk["modules"][0])
+    duplicate = deepcopy(
+        next(module for module in risk["modules"] if module["path"] == "obliteratus/cli.py")
+    )
     duplicate["required_tests"] = ["tests/missing.py"]
     duplicate["risk_class"] = "unknown"
     risk["modules"].append(duplicate)
@@ -94,3 +97,210 @@ def test_risk_map_cannot_drop_critical_cpu_path(tmp_path):
     )
 
     assert "critical CPU path is missing from test risk map: obliteratus/cli.py" in errors
+
+
+def test_contract_inventory_rejects_unmapped_and_multiply_owned_source(tmp_path):
+    risk = json.loads((ROOT / "ci" / "test-risk-map.json").read_text())
+    risk["source_inventory"]["roots"].append("scripts/check_test_risk_map.py")
+    second_surface = risk["contract_surfaces"][1]
+    second_surface["paths"].append("app.py")
+
+    errors = check_test_risk_map.validate(
+        _write(tmp_path / "risk.json", risk),
+        ROOT / "ci" / "test-quality-policy.json",
+        ROOT / "ci" / "conditional-test-policy.json",
+    )
+
+    assert "unmapped production source path: scripts/check_test_risk_map.py" in errors
+    assert (
+        "production source path has multiple contract owners: "
+        "app.py (package-entrypoints, core-pipeline)"
+    ) in errors
+
+
+def test_contract_surface_requires_valid_identity_contracts_and_tests(tmp_path):
+    risk = json.loads((ROOT / "ci" / "test-risk-map.json").read_text())
+    surface = risk["contract_surfaces"][0]
+    surface["id"] = "Invalid surface"
+    surface["owner"] = ""
+    surface["description"] = ""
+    surface["contract_types"] = ["package-entrypoint", "invented-contract", {"bad": "type"}]
+    surface["required_tests"] = ["tests/missing.py"]
+
+    errors = check_test_risk_map.validate(
+        _write(tmp_path / "risk.json", risk),
+        ROOT / "ci" / "test-quality-policy.json",
+        ROOT / "ci" / "conditional-test-policy.json",
+    )
+
+    assert "contract surface 0 has invalid id: 'Invalid surface'" in errors
+    assert "contract surface index-0 requires a non-empty owner" in errors
+    assert "contract surface index-0 requires a non-empty description" in errors
+    assert "contract surface index-0 has invalid contract type: 'invented-contract'" in errors
+    assert "contract surface index-0 has invalid contract type: {'bad': 'type'}" in errors
+    assert "contract surface index-0 maps missing test path: tests/missing.py" in errors
+
+
+def test_risk_module_must_resolve_to_contract_owner(tmp_path):
+    risk = json.loads((ROOT / "ci" / "test-risk-map.json").read_text())
+    surface = next(
+        item for item in risk["contract_surfaces"] if item["id"] == "public-interface-and-services"
+    )
+    surface["paths"].remove("obliteratus/cli.py")
+
+    errors = check_test_risk_map.validate(
+        _write(tmp_path / "risk.json", risk),
+        ROOT / "ci" / "test-quality-policy.json",
+        ROOT / "ci" / "conditional-test-policy.json",
+    )
+
+    assert "unmapped production source path: obliteratus/cli.py" in errors
+    assert "risk module is missing a contract owner: obliteratus/cli.py" in errors
+
+
+def test_risk_map_rejects_legacy_schema_and_invalid_inventory_roots(tmp_path):
+    risk = json.loads((ROOT / "ci" / "test-risk-map.json").read_text())
+    risk["schema_version"] = 1
+    risk["source_inventory"]["roots"] = ["missing-source-root", "/absolute/source.py"]
+
+    errors = check_test_risk_map.validate(
+        _write(tmp_path / "risk.json", risk),
+        ROOT / "ci" / "test-quality-policy.json",
+        ROOT / "ci" / "conditional-test-policy.json",
+    )
+
+    assert "test risk map schema_version must be 2" in errors
+    assert "source_inventory root does not exist: missing-source-root" in errors
+    assert "source_inventory has invalid root: '/absolute/source.py'" in errors
+
+
+def test_loader_rejects_unreadable_and_nonobject_documents(tmp_path):
+    errors = []
+    assert check_test_risk_map._load_object(tmp_path / "missing.json", "fixture", errors) == {}
+    assert errors and errors[0].startswith("cannot read fixture:")
+
+    errors = []
+    path = tmp_path / "list.json"
+    path.write_text("[]", encoding="utf-8")
+    assert check_test_risk_map._load_object(path, "fixture", errors) == {}
+    assert errors == ["fixture root must be an object"]
+
+
+def test_source_inventory_rejects_invalid_shape_duplicates_and_non_python_file(tmp_path):
+    risk = json.loads((ROOT / "ci" / "test-risk-map.json").read_text())
+    risk["source_inventory"] = {"roots": ["app.py", "app.py", "README.md"]}
+
+    errors = check_test_risk_map.validate(
+        _write(tmp_path / "risk.json", risk),
+        ROOT / "ci" / "test-quality-policy.json",
+        ROOT / "ci" / "conditional-test-policy.json",
+    )
+
+    assert "test risk map source_inventory has duplicate roots" in errors
+    assert "source_inventory root is not Python source: README.md" in errors
+    assert any(error.startswith("contract surface ") and "maps source outside inventory" in error for error in errors)
+
+    risk["source_inventory"] = []
+    errors = check_test_risk_map.validate(
+        _write(tmp_path / "risk-invalid.json", risk),
+        ROOT / "ci" / "test-quality-policy.json",
+        ROOT / "ci" / "conditional-test-policy.json",
+    )
+    assert "test risk map source_inventory must be an object" in errors
+
+
+def test_contract_surface_rejects_duplicate_and_malformed_fields(tmp_path):
+    risk = json.loads((ROOT / "ci" / "test-risk-map.json").read_text())
+    first = risk["contract_surfaces"][0]
+    second = risk["contract_surfaces"][1]
+    second["id"] = first["id"]
+    first["contract_types"] = ["public-interface", "public-interface"]
+    first["required_tests"] = ["tests/test_cli.py", "tests/test_cli.py", 42]
+    first["paths"] = ["app.py", "app.py", 42, "missing.py"]
+
+    errors = check_test_risk_map.validate(
+        _write(tmp_path / "risk.json", risk),
+        ROOT / "ci" / "test-quality-policy.json",
+        ROOT / "ci" / "conditional-test-policy.json",
+    )
+
+    assert "duplicate contract surface id: package-entrypoints" in errors
+    assert "contract surface package-entrypoints has duplicate contract types" in errors
+    assert "contract surface package-entrypoints has duplicate test paths" in errors
+    assert "contract surface package-entrypoints has invalid test path: 42" in errors
+    assert "contract surface package-entrypoints has duplicate source paths" in errors
+    assert "contract surface package-entrypoints has invalid source path: 42" in errors
+    assert "contract surface package-entrypoints maps source outside inventory: missing.py" in errors
+
+
+def test_contract_surface_and_module_collections_must_be_nonempty(tmp_path):
+    risk = json.loads((ROOT / "ci" / "test-risk-map.json").read_text())
+    risk["contract_surfaces"] = []
+    risk["modules"] = []
+
+    errors = check_test_risk_map.validate(
+        _write(tmp_path / "risk.json", risk),
+        ROOT / "ci" / "test-quality-policy.json",
+        ROOT / "ci" / "conditional-test-policy.json",
+    )
+
+    assert "test risk map contract_surfaces must be a non-empty list" in errors
+    assert "test risk map modules must be a non-empty list" in errors
+
+
+def test_risk_modules_reject_malformed_shape_risk_tests_and_gates(tmp_path):
+    risk = json.loads((ROOT / "ci" / "test-risk-map.json").read_text())
+    original_count = len(risk["modules"])
+    malformed = deepcopy(risk["modules"][0])
+    malformed["path"] = "obliteratus/cli.py"
+    malformed["risk"] = ""
+    malformed["required_tests"] = []
+    malformed["conditional_gates"] = ["unknown-gate", "unknown-gate", {"bad": "gate"}]
+    risk["modules"].extend([None, {}, malformed])
+
+    errors = check_test_risk_map.validate(
+        _write(tmp_path / "risk.json", risk),
+        ROOT / "ci" / "test-quality-policy.json",
+        ROOT / "ci" / "conditional-test-policy.json",
+    )
+
+    assert f"risk module {original_count} must be an object" in errors
+    assert f"risk module {original_count + 1} requires a non-empty path" in errors
+    assert "duplicate risk module path: obliteratus/cli.py" in errors
+    assert "risk module obliteratus/cli.py requires a non-empty risk" in errors
+    assert "risk module obliteratus/cli.py requires at least one test" in errors
+    assert "risk module obliteratus/cli.py has duplicate conditional gates" in errors
+    assert "risk module obliteratus/cli.py references unknown gate unknown-gate" in errors
+    assert "risk module obliteratus/cli.py has invalid conditional gate: {'bad': 'gate'}" in errors
+
+
+def test_quality_policy_collection_shapes_are_validated(tmp_path):
+    risk = ROOT / "ci" / "test-risk-map.json"
+    quality = json.loads((ROOT / "ci" / "test-quality-policy.json").read_text())
+    quality["mature_cpu_scope"]["exclusions"] = [None]
+    quality["critical_cpu_paths"] = "not-a-list"
+
+    errors = check_test_risk_map.validate(
+        risk,
+        _write(tmp_path / "quality.json", quality),
+        ROOT / "ci" / "conditional-test-policy.json",
+    )
+
+    assert "quality policy exclusion must be an object" in errors
+    assert "quality policy critical_cpu_paths must be a list" in errors
+
+
+def test_main_reports_success_and_failure(tmp_path, monkeypatch, capsys):
+    monkeypatch.setattr(sys, "argv", ["check_test_risk_map.py"])
+    assert check_test_risk_map.main() == 0
+    assert capsys.readouterr().out == "test risk map: valid\n"
+
+    bad_risk = tmp_path / "bad-risk.json"
+    bad_risk.write_text("{}", encoding="utf-8")
+    monkeypatch.setattr(
+        sys,
+        "argv",
+        ["check_test_risk_map.py", "--risk-map", str(bad_risk)],
+    )
+    assert check_test_risk_map.main() == 1
+    assert "ERROR: test risk map schema_version must be 2" in capsys.readouterr().out