наблюдаемость: ввести безопасный контракт метрик

tests/unit/test_check_rust_boundaries.py

@@ -27,6 +27,10 @@ def package(root: Path, name: str, rel_dir: str, dependencies: list[str] | None
     }
 
 
+def dependency(name: str, kind: str | None = None) -> dict:
+    return {"name": name, "kind": kind}
+
+
 def metadata(packages: list[dict], root: Path | None = None) -> dict:
     root = root or Path("/tmp/crank")
     return {
@@ -124,6 +128,44 @@ class RustBoundaryCheckTests(unittest.TestCase):
             self.assertEqual(violations[0].source, "crank-observability")
             self.assertEqual(violations[0].dependency, dependency)
 
+    def test_allows_observability_and_product_crates_to_depend_on_metrics_contract(self) -> None:
+        packages = [
+            package(
+                self.root,
+                "crank-observability",
+                "crates/crank-observability",
+                ["crank-metrics"],
+            ),
+            package(
+                self.root,
+                "crank-runtime",
+                "crates/crank-runtime",
+                ["crank-metrics"],
+            ),
+            package(self.root, "crank-metrics", "crates/crank-metrics"),
+        ]
+
+        violations = self.checker.find_violations(metadata(packages, self.root))
+
+        self.assertEqual(violations, [])
+
+    def test_rejects_metrics_contract_dependency_on_workspace_crates(self) -> None:
+        packages = [
+            package(
+                self.root,
+                "crank-metrics",
+                "crates/crank-metrics",
+                ["crank-core"],
+            ),
+            package(self.root, "crank-core", "crates/crank-core"),
+        ]
+
+        violations = self.checker.find_violations(metadata(packages, self.root))
+
+        self.assertEqual(len(violations), 1)
+        self.assertEqual(violations[0].source, "crank-metrics")
+        self.assertEqual(violations[0].dependency, "crank-core")
+
     def test_rejects_domain_and_runtime_dependencies_on_observability(self) -> None:
         for source in ("crank-core", "crank-registry", "crank-runtime"):
             packages = [
@@ -146,6 +188,23 @@ class RustBoundaryCheckTests(unittest.TestCase):
             self.assertEqual(violations[0].source, source)
             self.assertEqual(violations[0].dependency, "crank-observability")
 
+    def test_rejects_direct_production_metrics_dependency_outside_contract(self) -> None:
+        app = package(self.root, "admin-api", "apps/admin-api")
+        app["dependencies"] = [dependency("metrics")]
+
+        violations = self.checker.find_violations(metadata([app], self.root))
+
+        self.assertEqual(len(violations), 1)
+        self.assertEqual(violations[0].dependency, "metrics")
+
+    def test_allows_metrics_as_test_only_dependency(self) -> None:
+        app = package(self.root, "admin-api", "apps/admin-api")
+        app["dependencies"] = [dependency("metrics", "dev")]
+
+        violations = self.checker.find_violations(metadata([app], self.root))
+
+        self.assertEqual(violations, [])
+
 
 if __name__ == "__main__":
     unittest.main()