tiangolo.fastapi/tests/test_jsonable_encoder.py

import pytest
from fastapi.encoders import jsonable_encoder


class Person:
    def __init__(self, name: str):
        self.name = name


class Pet:
    def __init__(self, owner: Person, name: str):
        self.owner = owner
        self.name = name


class DictablePerson(Person):
    def __iter__(self):
        return ((k, v) for k, v in self.__dict__.items())


class DictablePet(Pet):
    def __iter__(self):
        return ((k, v) for k, v in self.__dict__.items())


class Unserializable:
    def __iter__(self):
        raise NotImplementedError()

    @property
    def __dict__(self):
        raise NotImplementedError()


def test_encode_class():
    person = Person(name="Foo")
    pet = Pet(owner=person, name="Firulais")
    assert jsonable_encoder(pet) == {"name": "Firulais", "owner": {"name": "Foo"}}


def test_encode_dictable():
    person = DictablePerson(name="Foo")
    pet = DictablePet(owner=person, name="Firulais")
    assert jsonable_encoder(pet) == {"name": "Firulais", "owner": {"name": "Foo"}}


def test_encode_unsupported():
    unserializable = Unserializable()
    with pytest.raises(ValueError):
        jsonable_encoder(unserializable)