datamodel-code-generator > 0.40.0 fails when using --url with a custom port

[GianlucaFicarelli]

Describe the bug
datamodel-code-generator > 0.40.0 fails when using --url with a custom port and retrieving a schema with $ref.

To Reproduce

Example schema:

{
  "openapi": "3.0.0",
  "info": {
    "title": "Minimal API",
    "version": "1.0.0"
  },
  "paths": {},
  "components": {
    "schemas": {
      "Item": {
        "type": "object",
        "properties": {
          "id": {
            "type": "string"
          },
          "owner": {
            "$ref": "#/components/schemas/User"
          }
        }
      },
      "User": {
        "type": "object",
        "properties": {
          "name": {
            "type": "string"
          }
        }
      }
    }
  }
}

Used commandline to start a server in the same directory where openapi.json is saved:

$ python -m http.server 8123

Used commandline:

$ datamodel-codegen --url http://127.0.0.1:8123/openapi.json

Expected behavior
The output should show the generated code as in version 0.40.0.

Version:

• OS: macOS 15.5
• Python version: 3.11.11
• datamodel-code-generator version: 0.52.1

Additional context
The error is httpx.ConnectError: [Errno 61] Connection refused

Looking at the logs, it seems that datamodel-codegen makes a first successful request to the endpoint, then it tries to make a new request to the wrong port 80, failing at:

datamodel-code-generator/src/datamodel_code_generator/parser/jsonschema.py

Line 3406 in 54c3ed9

return self.remote_object_cache.get_or_put(

Full traceback:

The input file type was determined to be: openapi
This can be specified explicitly with the `--input-file-type` option.
Traceback (most recent call last):
  File ".venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 101, in map_httpcore_exceptions
    yield
  File ".venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 250, in handle_request
    resp = self._pool.handle_request(req)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/httpcore/_sync/connection_pool.py", line 256, in handle_request
    raise exc from None
  File ".venv/lib/python3.11/site-packages/httpcore/_sync/connection_pool.py", line 236, in handle_request
    response = connection.handle_request(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/httpcore/_sync/connection.py", line 101, in handle_request
    raise exc
  File ".venv/lib/python3.11/site-packages/httpcore/_sync/connection.py", line 78, in handle_request
    stream = self._connect(request)
             ^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/httpcore/_sync/connection.py", line 124, in _connect
    stream = self._network_backend.connect_tcp(**kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/httpcore/_backends/sync.py", line 207, in connect_tcp
    with map_exceptions(exc_map):
  File "/Users/me/.local/share/uv/python/cpython-3.11.11-macos-aarch64-none/lib/python3.11/contextlib.py", line 158, in __exit__
    self.gen.throw(typ, value, traceback)
  File ".venv/lib/python3.11/site-packages/httpcore/_exceptions.py", line 14, in map_exceptions
    raise to_exc(exc) from exc
httpcore.ConnectError: [Errno 61] Connection refused

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/__main__.py", line 1363, in main
    run_generate_from_config(
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/__main__.py", line 938, in run_generate_from_config
    result = generate(
             ^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/__init__.py", line 764, in generate
    results = parser.parse(
              ^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/base.py", line 3107, in parse
    self.parse_raw()
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/openapi.py", line 753, in parse_raw
    self.parse_raw_obj(
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/jsonschema.py", line 3580, in parse_raw_obj
    self.parse_obj(name, obj, path)
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/jsonschema.py", line 3622, in parse_obj
    self.parse_object(name, obj, path)
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/jsonschema.py", line 2481, in parse_object
    fields = self.parse_object_fields(
             ^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/openapi.py", line 304, in parse_object_fields
    fields = super().parse_object_fields(obj, path, module_name, class_name=class_name)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/jsonschema.py", line 2421, in parse_object_fields
    field_type = self.parse_item(modular_name, field, [*path, field_name])
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/jsonschema.py", line 2767, in parse_item
    return self.get_ref_data_type(item.ref)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/openapi.py", line 294, in get_ref_data_type
    return super().get_ref_data_type(ref)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/jsonschema.py", line 1124, in get_ref_data_type
    ref_schema = self._load_ref_schema_object(ref)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/jsonschema.py", line 1379, in _load_ref_schema_object
    raw_doc = self._get_ref_body(file_part) if file_part else self.raw_obj
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/jsonschema.py", line 3387, in _get_ref_body
    return self._get_ref_body_from_url(resolved_ref)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/jsonschema.py", line 3406, in _get_ref_body_from_url
    return self.remote_object_cache.get_or_put(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/__init__.py", line 44, in get_or_put
    value = self[key] = default_factory(key)
                        ^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/jsonschema.py", line 3407, in <lambda>
    ref, default_factory=lambda key: load_data(self._get_text_from_url(key))
                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/base.py", line 1046, in _get_text_from_url
    return self.remote_text_cache.get_or_put(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/__init__.py", line 44, in get_or_put
    value = self[key] = default_factory(key)
                        ^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/parser/base.py", line 1048, in <lambda>
    default_factory=lambda _url: get_body(
                                 ^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/datamodel_code_generator/http.py", line 38, in get_body
    return httpx.get(
           ^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/httpx/_api.py", line 195, in get
    return request(
           ^^^^^^^^
  File ".venv/lib/python3.11/site-packages/httpx/_api.py", line 109, in request
    return client.request(
           ^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/httpx/_client.py", line 825, in request
    return self.send(request, auth=auth, follow_redirects=follow_redirects)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/httpx/_client.py", line 914, in send
    response = self._send_handling_auth(
               ^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/httpx/_client.py", line 942, in _send_handling_auth
    response = self._send_handling_redirects(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/httpx/_client.py", line 979, in _send_handling_redirects
    response = self._send_single_request(request)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/httpx/_client.py", line 1014, in _send_single_request
    response = transport.handle_request(request)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 249, in handle_request
    with map_httpcore_exceptions():
  File "/Users/me/.local/share/uv/python/cpython-3.11.11-macos-aarch64-none/lib/python3.11/contextlib.py", line 158, in __exit__
    self.gen.throw(typ, value, traceback)
  File ".venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 118, in map_httpcore_exceptions
    raise mapped_exc(message) from exc
httpx.ConnectError: [Errno 61] Connection refused

[koxudaxi]

Thank you for creating the issue.
This bug should be fixed as soon as possible. I will create the PR.

[github-actions]

🎉 Released in 0.52.2

The fix/feature from PR #2933 has been included in this release. See the release notes for details.

Thank you for your contribution!

[GianlucaFicarelli]

Thank you for the very quick fix and release 🎉