How do I generate typescript types for a recursive data type? #3634

smac89 · 2024-07-16T21:03:41Z

smac89
Jul 16, 2024

The following class causes issues when generating typescript types:

@dataclass
class Prefix:
    path: str
    is_special: bool
    name: str = field(init=False)
    parent: str | None = field(init=False)
    children: list["Prefix"] = field(default_factory=list)

    def __post_init__(self):
        path = self.path.rsplit("/", maxsplit=1)
        self.name = path[1] if len(path) > 1 else path[0]
        self.parent = None if len(path) == 1 else path[0]

I get the error

RecursionError: maximum recursion depth exceeded

As you can see, the Prefix.children property is a list[Prefix], which causes the recursion to continue indefinitely. How can I fix this?

Answered by smac89

Jul 17, 2024

So the route that uses the above class was declared like this:

@get("/list-prefixes")
async def list_prefixes(
    root: Optional[str] = "", depth: int = 2, only_scans: bool = False
) -> Iterable[Prefix]:
    result = list(fetch_prefixes(root, depth, only_scans))
    return result

Changing it to use a pagination type along with a DTO seems to have fixed the issue:

class ReadPrefixesDTO(DataclassDTO[Prefix]):
    config = DTOConfig(rename_strategy="camel")

@get("/list-prefixes", return_dto=ReadPrefixesDTO)
async def list_prefixes(
    root: Optional[str] = "", depth: int = 2, only_scans: bool = False
) -> ClassicPagination[Prefix]:
    result = list(fetch_prefixes(root, depth, only_scans)…

View full answer

smac89 · 2024-07-17T15:53:47Z

smac89
Jul 17, 2024
Author

So the route that uses the above class was declared like this:

@get("/list-prefixes")
async def list_prefixes(
    root: Optional[str] = "", depth: int = 2, only_scans: bool = False
) -> Iterable[Prefix]:
    result = list(fetch_prefixes(root, depth, only_scans))
    return result

Changing it to use a pagination type along with a DTO seems to have fixed the issue:

class ReadPrefixesDTO(DataclassDTO[Prefix]):
    config = DTOConfig(rename_strategy="camel")

@get("/list-prefixes", return_dto=ReadPrefixesDTO)
async def list_prefixes(
    root: Optional[str] = "", depth: int = 2, only_scans: bool = False
) -> ClassicPagination[Prefix]:
    result = list(fetch_prefixes(root, depth, only_scans))
    return ClassicPagination(
        items=result, page_size=len(result), current_page=1, total_pages=1
    )

I'm not sure I understand why this works, so any insight would be useful

0 replies

guacs · 2024-07-18T09:34:54Z

guacs
Jul 18, 2024
Maintainer

Hey! This might be a bug. The schema generation for recursive types was added in #2869 so it should be working without needing a DTO.

Could you show the full stacktrace??

1 reply

smac89 Jul 18, 2024
Author

Sure! Here is a traceback of the error stack

poetry run litestar schema typescript --output ../Test-Web/src/types/api.ts

Using Litestar app from app:app
Traceback (most recent call last):
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/bin/litestar", line 8, in 
    sys.exit(run_cli())
             ^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/__main__.py", line 6, in run_cli
    litestar_group()
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/rich_click/rich_command.py", line 367, in __call__
    return super().__call__(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/click/core.py", line 1157, in __call__
    return self.main(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/rich_click/rich_command.py", line 152, in main
    rv = self.invoke(ctx)
         ^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/click/core.py", line 1688, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/click/core.py", line 1688, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/click/core.py", line 1434, in invoke
    return ctx.invoke(self.callback, **ctx.params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/click/core.py", line 783, in invoke
    return __callback(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/click/decorators.py", line 33, in new_func
    return f(get_current_context(), *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/cli/_utils.py", line 254, in wrapped
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/click/decorators.py", line 33, in new_func
    return f(get_current_context(), *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/cli/_utils.py", line 254, in wrapped
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/cli/commands/schema.py", line 80, in generate_typescript_specs
    specs = convert_openapi_to_typescript(app.openapi_schema, namespace)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 299, in convert_openapi_to_typescript
    responses = parse_responses(operation.responses or {}, components=openapi_schema.components)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 226, in parse_responses
    content := [get_openapi_type(v.schema, components) for v in response.content.values() if v.schema]
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 135, in get_openapi_type
    return deref_container(open_api_container=value, components=components)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 89, in deref_container
    return cast("T", _deref_schema_object(open_api_container, components))
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 56, in _deref_schema_object
    setattr(value, field.name, deref_container(field_value, components=components))
                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 92, in deref_container
    return cast("T", _deref_dict(copy(open_api_container), components))
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 65, in _deref_dict
    value[k] = deref_container(v, components=components)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 89, in deref_container
    return cast("T", _deref_schema_object(open_api_container, components))
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 53, in _deref_schema_object
    deref_container(resolve_ref(field_value, components=components), components=components),
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...

(Previous 6 tracebacks repeat a bunch of times)
File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 89, in deref_container

return cast("T", _deref_schema_object(open_api_container, components))

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 56, in _deref_schema_object

setattr(value, field.name, deref_container(field_value, components=components))

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 92, in deref_container

return cast("T", _deref_dict(copy(open_api_container), components))

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 65, in _deref_dict

value[k] = deref_container(v, components=components)

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 89, in deref_container

return cast("T", _deref_schema_object(open_api_container, components))

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 56, in _deref_schema_object

setattr(value, field.name, deref_container(field_value, components=components))

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 95, in deref_container

return cast("T", _deref_list(copy(open_api_container), components))

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 74, in _deref_list

values[i] = deref_container(value, components=components)

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 89, in deref_container

return cast("T", _deref_schema_object(open_api_container, components))

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "/home/nobleman/Development/TestApp/Test-Server/.venv/lib/python3.12/site-packages/litestar/_openapi/typescript_converter/converter.py", line 47, in _deref_schema_object

for field in fields(value):

^^^^^^^^^^^^^

File "/usr/lib/python3.12/dataclasses.py", line 1293, in fields

return tuple(f for f in fields.values() if f._field_type is _FIELD)

RecursionError: maximum recursion depth exceeded

@guacs I had to cut it short otherwise, it wouldn't fit.

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Litestar

How do I generate typescript types for a recursive data type? #3634

smac89 Jul 16, 2024

Replies: 2 comments · 1 reply

smac89 Jul 17, 2024 Author

guacs Jul 18, 2024 Maintainer

smac89 Jul 18, 2024 Author

smac89
Jul 16, 2024

Replies: 2 comments 1 reply

smac89
Jul 17, 2024
Author

guacs
Jul 18, 2024
Maintainer

smac89 Jul 18, 2024
Author