feat(access-control-prover): 8.4 inheritance and base-declaration attachment through repo-defined descendants

tests/test_inheritance_attachment.py

@@ -0,0 +1,127 @@
+"""Task 8.4 -- inheritance and base-declaration attachment (Req 3.5).
+
+Base-type operations and entries attach only through repository-defined
+descendant relations; ambiguous inheritance stays incomplete; unrelated
+same-name classes never receive attachments (the mage-ai shape).
+"""
+
+from __future__ import annotations
+
+from openultrasast.semantic.obligations.abstract_domain import Completeness
+from openultrasast.semantic.obligations.resolution import (
+    SymbolIndex,
+    ancestors_of,
+    descendants_of,
+    inherited_method,
+)
+
+JAVA_BASE = (
+    "src/Base.java",
+    "public class Base { public void run(String command) { } }",
+    "java",
+)
+JAVA_SUB = (
+    "src/Sub.java",
+    "public class Sub extends Base { public void handle() { } }",
+    "java",
+)
+JAVA_UNRELATED = (
+    "src/Other.java",
+    "public class Unrelated { public void run(String command) { } }",
+    "java",
+)
+JAVA_CHAIN = (
+    "src/Chain.java",
+    "public class A extends B { } class B extends C { } class C { public void audit(String request) { } }",
+    "java",
+)
+JAVA_CYCLE = (
+    "src/Cycle.java",
+    "public class P extends Q { } class Q extends P { }",
+    "java",
+)
+PHP_BASE_A = (
+    "a/Base.php",
+    "<?php class Base { public function run($command) { } }",
+    "php",
+)
+PHP_BASE_B = (
+    "b/Base.php",
+    "<?php class Base { public function run($command) { } }",
+    "php",
+)
+
+
+def _index(*files: tuple[str, str, str]) -> SymbolIndex:
+    return SymbolIndex.build(files)
+
+
+def test_ancestors_walk_the_transitive_chain_nearest_first() -> None:
+    index = _index(JAVA_CHAIN)
+
+    assert ancestors_of(index, "src/Chain.java", "A") == ("B", "C")
+
+
+def test_ancestors_survive_inheritance_cycles_without_hanging() -> None:
+    index = _index(JAVA_CYCLE)
+
+    assert ancestors_of(index, "src/Cycle.java", "P") == ("Q",)
+
+
+def test_descendants_cover_only_repo_defined_descendants() -> None:
+    index = _index(JAVA_BASE, JAVA_SUB, JAVA_UNRELATED)
+
+    assert descendants_of(index, "Base") == (("src/Sub.java", "Sub"),)
+
+
+def test_inherited_method_resolves_complete_on_a_unique_base() -> None:
+    index = _index(JAVA_BASE, JAVA_SUB, JAVA_UNRELATED)
+
+    target_set = inherited_method(index, "Base", "run", arity=1)
+
+    assert [symbol.enclosing_type for symbol in target_set.targets] == ["Base"]
+    assert target_set.completeness == Completeness(is_complete=True)
+
+
+def test_inherited_method_is_absent_when_no_base_declares_it() -> None:
+    index = _index(JAVA_BASE, JAVA_SUB, JAVA_UNRELATED)
+
+    target_set = inherited_method(index, "Base", "handle", arity=None)
+
+    assert target_set.targets == ()
+    assert target_set.completeness == Completeness(is_complete=False, reasons=("resolution:no_candidate",))
+
+
+def test_inherited_method_keeps_ambiguous_bases_as_incomplete_candidates() -> None:
+    index = _index(PHP_BASE_A, PHP_BASE_B)
+
+    target_set = inherited_method(index, "Base", "run", arity=None)
+
+    assert len(target_set.targets) == 2
+    assert {symbol.module for symbol in target_set.targets} == {"a/Base.php", "b/Base.php"}
+    assert target_set.completeness == Completeness(is_complete=False, reasons=("resolution:inheritance_ambiguous_across_modules",))
+
+
+def test_inherited_method_narrows_overloads_by_arity() -> None:
+    overloaded_base = (
+        "src/Ops.java",
+        "public class Ops { public void go() { } public void go(String payload) { } }",
+        "java",
+    )
+    index = _index(overloaded_base)
+
+    target_set = inherited_method(index, "Ops", "go", arity=1)
+
+    assert [symbol.signature for symbol in target_set.targets] == [("payload",)]
+    assert target_set.completeness == Completeness(is_complete=True)
+
+
+def test_unrelated_same_name_classes_never_receive_base_attachments() -> None:
+    index = _index(JAVA_BASE, JAVA_SUB, JAVA_UNRELATED)
+
+    target_set = inherited_method(index, "Base", "run", arity=1)
+    unrelated = index.by_name["run"]
+
+    assert all(symbol.enclosing_type == "Base" for symbol in target_set.targets)
+    assert ("src/Other.java", "Unrelated") not in descendants_of(index, "Base")
+    assert any(symbol.enclosing_type == "Unrelated" and symbol.module == "src/Other.java" for symbol in unrelated)