fix: prevent infinite recursion on visitor2

src/common/src/typegraph/visitor2.rs

@@ -90,8 +90,15 @@ fn traverse_types_with_path<'tg, A, V, E>(
 where
     V: Fn(VisitorContext<'tg>, &mut A) -> Result<VisitNext, E>,
 {
+    let cyclic = path.borrow().iter().any(|segment| segment.from == type_idx);
+    if cyclic {
+        return Ok(TraverseOutput {
+            accumulator,
+            stop: false,
+        });
+    }
+
     let type_node = &tg.types[type_idx as usize];
-    // TODO check for cycles
 
     // visit current
     {

tests/metagen/typegraphs/python.py

@@ -18,6 +18,7 @@ def example(g: Graph):
             "email": t.email().optional(),
             "list_integer": t.list(t.integer()),
             "opt_union_flat": t.union([t.integer(), t.float()]).optional(),
+            "file": t.file().optional(),
             "reference": t.list(g.ref("Example")).optional(),
             "nested_ref": t.struct(
                 {"either": t.either([g.ref("Example"), references])}