Move shell configuration out of desktop core

scripts/tests/test_component_boundaries.py

@@ -0,0 +1,41 @@
+"""Keep production dependencies within the boundaries in ADR 0004."""
+import pathlib
+import tomllib
+import unittest
+
+ROOT = pathlib.Path(__file__).resolve().parents[2]
+
+
+def dependency_graph():
+    workspace = tomllib.loads((ROOT / "Cargo.toml").read_text())
+    graph = {}
+    for member in workspace["workspace"]["members"]:
+        manifest = tomllib.loads((ROOT / member / "Cargo.toml").read_text())
+        dependencies = set(manifest.get("dependencies", {}))
+        for target in manifest.get("target", {}).values():
+            dependencies.update(target.get("dependencies", {}))
+        graph[manifest["package"]["name"]] = dependencies
+    return graph
+
+
+def reachable(graph, package):
+    seen = set()
+    pending = list(graph.get(package, ()))
+    while pending:
+        dependency = pending.pop()
+        if dependency not in seen:
+            seen.add(dependency)
+            pending.extend(graph.get(dependency, ()))
+    return seen
+
+
+class ComponentBoundaries(unittest.TestCase):
+    def test_shell_does_not_depend_on_core(self):
+        self.assertNotIn("ferese-core", reachable(dependency_graph(), "ferese-shell"))
+
+    def test_transitive_dependencies_are_checked(self):
+        self.assertIn("core", reachable({"shell": {"helper"}, "helper": {"core"}}, "shell"))
+
+
+if __name__ == "__main__":
+    unittest.main()