tiangolo.fastapi/tests/test_jsonable_encoder.py

from collections import deque
from dataclasses import dataclass
from datetime import datetime, timezone
from decimal import Decimal
from enum import Enum
from pathlib import PurePath, PurePosixPath, PureWindowsPath
from typing import Optional

import pytest
from fastapi._compat import PYDANTIC_V2, Undefined
from fastapi.encoders import jsonable_encoder
from pydantic import BaseModel, Field, ValidationError

from .utils import needs_pydanticv1, needs_pydanticv2


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


@dataclass
class Item:
    name: str
    count: int


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()


class RoleEnum(Enum):
    admin = "admin"
    normal = "normal"


class ModelWithConfig(BaseModel):
    role: Optional[RoleEnum] = None

    if PYDANTIC_V2:
        model_config = {"use_enum_values": True}
    else:

        class Config:
            use_enum_values = True


class ModelWithAlias(BaseModel):
    foo: str = Field(alias="Foo")


class ModelWithDefault(BaseModel):
    foo: str = ...  # type: ignore
    bar: str = "bar"
    bla: str = "bla"


def test_encode_dict():
    pet = {"name": "Firulais", "owner": {"name": "Foo"}}
    assert jsonable_encoder(pet) == {"name": "Firulais", "owner": {"name": "Foo"}}
    assert jsonable_encoder(pet, include={"name"}) == {"name": "Firulais"}
    assert jsonable_encoder(pet, exclude={"owner"}) == {"name": "Firulais"}
    assert jsonable_encoder(pet, include={}) == {}
    assert jsonable_encoder(pet, exclude={}) == {
        "name": "Firulais",
        "owner": {"name": "Foo"},
    }


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


def test_encode_dataclass():
    item = Item(name="foo", count=100)
    assert jsonable_encoder(item) == {"name": "foo", "count": 100}
    assert jsonable_encoder(item, include={"name"}) == {"name": "foo"}
    assert jsonable_encoder(item, exclude={"count"}) == {"name": "foo"}
    assert jsonable_encoder(item, include={}) == {}
    assert jsonable_encoder(item, exclude={}) == {"name": "foo", "count": 100}


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


@needs_pydanticv2
def test_encode_custom_json_encoders_model_pydanticv2():
    from pydantic import field_serializer

    class ModelWithCustomEncoder(BaseModel):
        dt_field: datetime

        @field_serializer("dt_field")
        def serialize_dt_field(self, dt):
            return dt.replace(microsecond=0, tzinfo=timezone.utc).isoformat()

    class ModelWithCustomEncoderSubclass(ModelWithCustomEncoder):
        pass

    model = ModelWithCustomEncoder(dt_field=datetime(2019, 1, 1, 8))
    assert jsonable_encoder(model) == {"dt_field": "2019-01-01T08:00:00+00:00"}
    subclass_model = ModelWithCustomEncoderSubclass(dt_field=datetime(2019, 1, 1, 8))
    assert jsonable_encoder(subclass_model) == {"dt_field": "2019-01-01T08:00:00+00:00"}


# TODO: remove when deprecating Pydantic v1
@needs_pydanticv1
def test_encode_custom_json_encoders_model_pydanticv1():
    class ModelWithCustomEncoder(BaseModel):
        dt_field: datetime

        class Config:
            json_encoders = {
                datetime: lambda dt: dt.replace(
                    microsecond=0, tzinfo=timezone.utc
                ).isoformat()
            }

    class ModelWithCustomEncoderSubclass(ModelWithCustomEncoder):
        class Config:
            pass

    model = ModelWithCustomEncoder(dt_field=datetime(2019, 1, 1, 8))
    assert jsonable_encoder(model) == {"dt_field": "2019-01-01T08:00:00+00:00"}
    subclass_model = ModelWithCustomEncoderSubclass(dt_field=datetime(2019, 1, 1, 8))
    assert jsonable_encoder(subclass_model) == {"dt_field": "2019-01-01T08:00:00+00:00"}


def test_encode_model_with_config():
    model = ModelWithConfig(role=RoleEnum.admin)
    assert jsonable_encoder(model) == {"role": "admin"}


def test_encode_model_with_alias_raises():
    with pytest.raises(ValidationError):
        ModelWithAlias(foo="Bar")


def test_encode_model_with_alias():
    model = ModelWithAlias(Foo="Bar")
    assert jsonable_encoder(model) == {"Foo": "Bar"}


def test_encode_model_with_default():
    model = ModelWithDefault(foo="foo", bar="bar")
    assert jsonable_encoder(model) == {"foo": "foo", "bar": "bar", "bla": "bla"}
    assert jsonable_encoder(model, exclude_unset=True) == {"foo": "foo", "bar": "bar"}
    assert jsonable_encoder(model, exclude_defaults=True) == {"foo": "foo"}
    assert jsonable_encoder(model, exclude_unset=True, exclude_defaults=True) == {
        "foo": "foo"
    }
    assert jsonable_encoder(model, include={"foo"}) == {"foo": "foo"}
    assert jsonable_encoder(model, exclude={"bla"}) == {"foo": "foo", "bar": "bar"}
    assert jsonable_encoder(model, include={}) == {}
    assert jsonable_encoder(model, exclude={}) == {
        "foo": "foo",
        "bar": "bar",
        "bla": "bla",
    }


@needs_pydanticv1
def test_custom_encoders():
    class safe_datetime(datetime):
        pass

    class MyModel(BaseModel):
        dt_field: safe_datetime

    instance = MyModel(dt_field=safe_datetime.now())

    encoded_instance = jsonable_encoder(
        instance, custom_encoder={safe_datetime: lambda o: o.isoformat()}
    )
    assert encoded_instance["dt_field"] == instance.dt_field.isoformat()


def test_custom_enum_encoders():
    def custom_enum_encoder(v: Enum):
        return v.value.lower()

    class MyEnum(Enum):
        ENUM_VAL_1 = "ENUM_VAL_1"

    instance = MyEnum.ENUM_VAL_1

    encoded_instance = jsonable_encoder(
        instance, custom_encoder={MyEnum: custom_enum_encoder}
    )
    assert encoded_instance == custom_enum_encoder(instance)


def test_encode_model_with_pure_path():
    class ModelWithPath(BaseModel):
        path: PurePath

        if PYDANTIC_V2:
            model_config = {"arbitrary_types_allowed": True}
        else:

            class Config:
                arbitrary_types_allowed = True

    test_path = PurePath("/foo", "bar")
    obj = ModelWithPath(path=test_path)
    assert jsonable_encoder(obj) == {"path": str(test_path)}


def test_encode_model_with_pure_posix_path():
    class ModelWithPath(BaseModel):
        path: PurePosixPath

        if PYDANTIC_V2:
            model_config = {"arbitrary_types_allowed": True}
        else:

            class Config:
                arbitrary_types_allowed = True

    obj = ModelWithPath(path=PurePosixPath("/foo", "bar"))
    assert jsonable_encoder(obj) == {"path": "/foo/bar"}


def test_encode_model_with_pure_windows_path():
    class ModelWithPath(BaseModel):
        path: PureWindowsPath

        if PYDANTIC_V2:
            model_config = {"arbitrary_types_allowed": True}
        else:

            class Config:
                arbitrary_types_allowed = True

    obj = ModelWithPath(path=PureWindowsPath("/foo", "bar"))
    assert jsonable_encoder(obj) == {"path": "\\foo\\bar"}


@needs_pydanticv1
def test_encode_root():
    class ModelWithRoot(BaseModel):
        __root__: str

    model = ModelWithRoot(__root__="Foo")
    assert jsonable_encoder(model) == "Foo"


@needs_pydanticv2
def test_decimal_encoder_float():
    data = {"value": Decimal(1.23)}
    assert jsonable_encoder(data) == {"value": 1.23}


@needs_pydanticv2
def test_decimal_encoder_int():
    data = {"value": Decimal(2)}
    assert jsonable_encoder(data) == {"value": 2}


def test_encode_deque_encodes_child_models():
    class Model(BaseModel):
        test: str

    dq = deque([Model(test="test")])

    assert jsonable_encoder(dq)[0]["test"] == "test"


@needs_pydanticv2
def test_encode_pydantic_undefined():
    data = {"value": Undefined}
    assert jsonable_encoder(data) == {"value": None}