fix(vbnet): link enum members with case_of instead of contains

(cherry picked from commit 6ee9624c22)

graphify/extractors/vbnet.py

@@ -185,14 +185,16 @@ def extract_vbnet(path: Path) -> dict:
             source_backed=False,
         )
 
-    def add_data_member(type_id: str, member: Node, name: str, kind: str) -> str:
+    def add_data_member(
+        type_id: str, member: Node, name: str, kind: str, relation: str = "contains"
+    ) -> str:
         member_id = add_node(
             _make_id(type_id, kind, name.casefold(), str(member.start_point[0])),
             name,
             member,
             kind=kind,
         )
-        add_edge(type_id, member_id, "contains", member)
+        add_edge(type_id, member_id, relation, member)
         return member_id
 
     def process_type(block: Node, parent_id: str, namespace: str) -> None:
@@ -227,8 +229,15 @@ def extract_vbnet(path: Path) -> dict:
             if member.type == "enum_member":
                 member_name = member.child_by_field_name("name")
                 if member_name is not None:
+                    # An enum member is a discriminant case, not a contained
+                    # declaration: it gets a `case_of` edge like every other
+                    # language with enums (Java #1719, C#, Swift, Scala, ...),
+                    # not the `contains` edge used for real fields. The relation
+                    # also matters to resolution — case_of targets are excluded
+                    # from `New X()` constructor binding (see _member_nids).
                     add_data_member(
-                        type_id, member, _read_text(member_name, source), "enum_member"
+                        type_id, member, _read_text(member_name, source),
+                        "enum_member", relation="case_of",
                     )
                 continue
             if member.type == "field_declaration":

tests/test_vbnet_extractor.py

@@ -188,3 +188,39 @@ def test_vbnet_missing_parser_reports_install_hint(tmp_path, monkeypatch, capsys
 
     assert result["nodes"] == []
     assert 'pip install "graphifyy[vbnet]"' in capsys.readouterr().err
+
+
+def test_vbnet_enum_members_emit_case_of_not_contains(tmp_path):
+    """A VB.NET enum member is a discriminant case, so it must get a `case_of`
+    edge like every other language with enums (Java #1719, C#, Swift, Scala),
+    not the `contains` edge used for real fields. VB.NET was the lone outlier,
+    routing enum members through the same `contains` path as class fields. The
+    relation also matters to resolution: `case_of` targets are excluded from
+    `New X()` constructor binding, so an enum member named like a type can no
+    longer be mistaken for one.
+    """
+    source = tmp_path / "Enums.vb"
+    source.write_text(
+        "Public Enum Color\n"
+        "  Red\n"
+        "  Green\n"
+        "  Blue\n"
+        "End Enum\n"
+        "Public Class Widget\n"
+        "  Private count As Integer\n"
+        "End Class\n",
+        encoding="utf-8",
+    )
+
+    result = extract([source], cache_root=tmp_path)
+
+    case_of = _edge_labels(result, "case_of")
+    contains = _edge_labels(result, "contains")
+    # Each enum member hangs off its enum via case_of, not contains.
+    assert ("Color", "Red") in case_of
+    assert ("Color", "Green") in case_of
+    assert ("Color", "Blue") in case_of
+    assert ("Color", "Red") not in contains
+    # A real class field is a declaration, not a case: it keeps `contains`.
+    assert ("Widget", "count") in contains
+    assert ("Widget", "count") not in case_of