test_issue.py

import json
from dataclasses import dataclass
from typing import List, Optional

from apispec import APISpec

from dataclasses_jsonschema import JsonSchemaMixin
from dataclasses_jsonschema.apispec import DataclassesPlugin

# Create an APISpec
spec = APISpec(
    title="Swagger Petstore",
    version="1.0.0",
    openapi_version="3.0.2",
    plugins=[DataclassesPlugin()],
)


@dataclass
class Category(JsonSchemaMixin):
    """Pet category"""

    name: str
    id: Optional[int]


@dataclass
class Pet(JsonSchemaMixin):
    """A pet"""

    categories: List[Category]
    name: str


@dataclass
class Cat(Pet):
    """A cat"""

    color: str


# Dependant schemas (e.g. 'Category') are added automatically
spec.components.schema("Pet", schema=Pet)
spec.components.schema("Cat", schema=Cat)
print(json.dumps(spec.to_dict(), indent=2))