Merge pull request #306 from Fatal1ty/fix-type-alias-type-name

Fix type_name for TypeAliasType

Author: Fatal1ty

mashumaro/core/meta/helpers.py

@@ -129,6 +129,7 @@ def _get_args_str(
     limit: Optional[int] = None,
     none_type_as_none: bool = False,
     sep: str = ", ",
+    _type_alias_guard: Optional[set[int]] = None,
 ) -> str:
     if typ == Tuple[()]:
         return "()"
@@ -143,6 +144,7 @@ def _get_args_str(
                 short=short,
                 resolved_type_params=resolved_type_params,
                 none_type_as_none=none_type_as_none,
+                _type_alias_guard=_type_alias_guard,
             )
         )
     if len(to_join) > 1:
@@ -184,14 +186,17 @@ def _typing_name(
 
 
 def type_name(
-    typ: Optional[Type],
+    typ: Union[Type, Any],
     short: bool = False,
     resolved_type_params: Optional[dict[Type, Type]] = None,
     is_type_origin: bool = False,
     none_type_as_none: bool = False,
+    _type_alias_guard: Optional[set[int]] = None,
 ) -> str:
     if resolved_type_params is None:
         resolved_type_params = {}
+    if _type_alias_guard is None:
+        _type_alias_guard = set()
     if typ is None:
         return "None"
     elif typ is NoneType and none_type_as_none:
@@ -205,15 +210,25 @@ def type_name(
             typ=not_none_type_arg(get_args(typ), resolved_type_params),
             short=short,
             resolved_type_params=resolved_type_params,
+            _type_alias_guard=_type_alias_guard,
         )
         return f"{_typing_name('Optional', short)}[{args_str}]"
     elif is_union(typ):
         args_str = _get_args_str(
-            typ, short, resolved_type_params, none_type_as_none=True
+            typ=typ,
+            short=short,
+            resolved_type_params=resolved_type_params,
+            none_type_as_none=True,
+            _type_alias_guard=_type_alias_guard,
         )
         return f"{_typing_name('Union', short)}[{args_str}]"
     elif is_annotated(typ):
-        return type_name(get_args(typ)[0], short, resolved_type_params)
+        return type_name(
+            typ=get_args(typ)[0],
+            short=short,
+            resolved_type_params=resolved_type_params,
+            _type_alias_guard=_type_alias_guard,
+        )
     elif not is_type_origin and is_literal(typ):
         args_str = _get_literal_values_str(typ, short)
         return f"{_typing_name('Literal', short, typ.__module__)}[{args_str}]"
@@ -223,26 +238,40 @@ def type_name(
             and resolved_type_params[typ] is not typ
         ):
             return type_name(
-                resolved_type_params[typ], short, resolved_type_params
+                typ=resolved_type_params[typ],
+                short=short,
+                resolved_type_params=resolved_type_params,
+                _type_alias_guard=_type_alias_guard,
             )
         else:
             unpacked_type_arg = get_args(typ)[0]
             if not is_variable_length_tuple(
                 unpacked_type_arg
             ) and not is_type_var_tuple(unpacked_type_arg):
                 return _get_args_str(
-                    unpacked_type_arg, short, resolved_type_params
+                    typ=unpacked_type_arg,
+                    short=short,
+                    resolved_type_params=resolved_type_params,
+                    _type_alias_guard=_type_alias_guard,
                 )
             unpacked_type_name = type_name(
-                unpacked_type_arg, short, resolved_type_params
+                typ=unpacked_type_arg,
+                short=short,
+                resolved_type_params=resolved_type_params,
+                _type_alias_guard=_type_alias_guard,
             )
             if PY_311_MIN:
                 return f"*{unpacked_type_name}"
             else:
                 _unpack = _typing_name("Unpack", short, typ.__module__)
                 return f"{_unpack}[{unpacked_type_name}]"
     elif not is_type_origin and is_generic(typ):
-        args_str = _get_args_str(typ, short, resolved_type_params)
+        args_str = _get_args_str(
+            typ=typ,
+            short=short,
+            resolved_type_params=resolved_type_params,
+            _type_alias_guard=_type_alias_guard,
+        )
         if not args_str:
             return get_generic_name(typ, short)
         else:
@@ -255,25 +284,55 @@ def type_name(
             and resolved_type_params[typ] is not typ
         ):
             return type_name(
-                resolved_type_params[typ], short, resolved_type_params
+                typ=resolved_type_params[typ],
+                short=short,
+                resolved_type_params=resolved_type_params,
+                _type_alias_guard=_type_alias_guard,
             )
         elif is_type_var_any(typ):
             return _typing_name("Any", short)
         constraints = getattr(typ, "__constraints__")
         if constraints:
             args_str = ", ".join(
-                type_name(c, short, resolved_type_params) for c in constraints
+                type_name(
+                    typ=c,
+                    short=short,
+                    resolved_type_params=resolved_type_params,
+                    _type_alias_guard=_type_alias_guard,
+                )
+                for c in constraints
             )
             return f"{_typing_name('Union', short)}[{args_str}]"
         else:
             if type_var_has_default(typ):
                 bound = get_type_var_default(typ)
             else:
                 bound = getattr(typ, "__bound__")
-            return type_name(bound, short, resolved_type_params)
+            return type_name(
+                typ=bound,
+                short=short,
+                resolved_type_params=resolved_type_params,
+                _type_alias_guard=_type_alias_guard,
+            )
     elif is_new_type(typ) and not PY_310_MIN:
         # because __qualname__ and __module__ are messed up
         typ = typ.__supertype__
+    if is_type_alias_type(typ):
+        alias_id = id(typ)
+        if alias_id in _type_alias_guard:
+            return typ.__name__
+        _type_alias_guard.add(alias_id)
+        try:
+            return type_name(
+                typ=typ.__value__,
+                short=short,
+                resolved_type_params=resolved_type_params,
+                is_type_origin=is_type_origin,
+                none_type_as_none=none_type_as_none,
+                _type_alias_guard=_type_alias_guard,
+            )
+        finally:
+            _type_alias_guard.discard(alias_id)
     try:
         if short:
             return typ.__qualname__  # type: ignore

tests/conftest.py

@@ -8,6 +8,7 @@
         "test_pep_695.py",
         "test_recursive_union.py",
         "test_jsonschema/test_jsonschema_pep_695.py",
+        "test_type_alias_type_name.py",
     ]
 
 add_unpack_method = patch(

tests/test_type_alias_type_name.py

@@ -0,0 +1,20 @@
+import pytest
+
+from mashumaro.core.meta.helpers import type_name
+
+type JSON = str | int | float | bool | dict[str, JSON] | list[JSON] | None
+type A = int | list[B]
+type B = str | list[A]
+
+
+def test_type_name_recursive_type_alias_does_not_recurse_forever() -> None:
+    # Must not raise RecursionError
+    s = type_name(JSON, short=True)
+    assert "JSON" in s
+
+
+def test_type_name_mutual_recursive_type_aliases_does_not_recurse_forever() -> (
+    None
+):
+    s = type_name(A, short=True)
+    assert "A" in s