Make tenancy an optional access integration

tests/test_optional_tenancy_contract.py

@@ -0,0 +1,59 @@
+from __future__ import annotations
+
+import ast
+import pathlib
+import tomllib
+import unittest
+
+
+ROOT = pathlib.Path(__file__).resolve().parents[1]
+
+
+class OptionalTenancyContractTests(unittest.TestCase):
+    def test_access_package_does_not_require_tenancy_to_install(self) -> None:
+        project = tomllib.loads((ROOT / "pyproject.toml").read_text(encoding="utf-8"))["project"]
+
+        dependencies = tuple(project["dependencies"])
+
+        self.assertIn("govoplan-core>=0.1.6", dependencies)
+        self.assertNotIn("govoplan-tenancy>=0.1.6", dependencies)
+        self.assertFalse(any(item.startswith("govoplan-tenancy") for item in dependencies))
+
+    def test_tenancy_is_declared_as_optional_module_integration(self) -> None:
+        manifest_path = ROOT / "src" / "govoplan_access" / "backend" / "manifest.py"
+        tree = ast.parse(manifest_path.read_text(encoding="utf-8"))
+        manifest_call = next(
+            node.value
+            for node in ast.walk(tree)
+            if isinstance(node, ast.Assign)
+            and any(isinstance(target, ast.Name) and target.id == "manifest" for target in node.targets)
+            and isinstance(node.value, ast.Call)
+        )
+        optional_dependencies = next(
+            keyword.value
+            for keyword in manifest_call.keywords
+            if keyword.arg == "optional_dependencies"
+        )
+
+        self.assertIsInstance(optional_dependencies, ast.Tuple)
+        self.assertIn(
+            "tenancy",
+            {
+                item.value
+                for item in optional_dependencies.elts
+                if isinstance(item, ast.Constant) and isinstance(item.value, str)
+            },
+        )
+
+    def test_access_source_does_not_import_tenancy_module_internals(self) -> None:
+        offenders: list[str] = []
+        for path in (ROOT / "src" / "govoplan_access").rglob("*.py"):
+            source = path.read_text(encoding="utf-8")
+            if "govoplan_tenancy" in source:
+                offenders.append(str(path.relative_to(ROOT)))
+
+        self.assertEqual([], offenders)
+
+
+if __name__ == "__main__":
+    unittest.main()