pydantic error case for GenericModel

00_test_showing_error.py

from typing import TypeVar, Generic

import pytest
from pydantic import BaseModel, PrivateAttr
from pydantic.generics import GenericModel


class Regular(BaseModel):
    value: int


T = TypeVar('T')
T_Bound = TypeVar('T_Bound', bound=Regular)


class RegGen(BaseModel, Generic[T_Bound]):
    value: T_Bound
    _privateattr: T_Bound = PrivateAttr(None)


class GenBound(GenericModel, Generic[T_Bound]):
    value: T_Bound
    _privateattr: T_Bound = PrivateAttr(None)


class GenT(GenericModel, Generic[T]):
    value: T
    _privateattr: T = PrivateAttr(None)


class Outer(BaseModel):

    a: GenBound[Regular]
    b: GenT[int]
    c: RegGen[Regular]


@pytest.fixture
def regular():
    regular = Regular(value=8)
    return regular


@pytest.fixture
def a(regular):
    a = GenBound(value=regular)
    a._privateattr = regular
    return a

@pytest.fixture
def b():
    b = GenT(value=42)
    b._privateattr = 42
    return b

@pytest.fixture
def c(regular):
    c = RegGen(value=regular)
    c._privateattr = regular
    return c

@pytest.fixture()
def o(a, b, c):
    o = Outer(a=a, b=b, c=c)
    return o


def test_equality(o: Outer, a: GenBound[Regular], b: GenT[int], c: RegGen[Regular], regular: Regular):
    assert o.a == a
    assert o.b == b
    assert o.c == c
    assert o.a.value == regular
    assert o.b.value == 42
    assert o.c.value == regular


def test_private_attr_generic_bound(o: Outer, regular: Regular):
    assert o.a._privateattr == regular

def test_private_attr_generic_unbound(o: Outer):
    assert o.b._privateattr == 42

def test_private_attr_basemodel_generic(o: Outer, regular: Regular):
    assert o.c._privateattr == regular


if __name__ == '__main__':
    import pytest
    pytest.main([__file__])

01_output.txt

============================= test session starts ==============================
platform darwin -- Python 3.8.3, pytest-5.4.3, py-1.8.1, pluggy-0.13.1
rootdir: /Users/mvanniekerk/Library/Application Support/JetBrains/PyCharm2020.3/scratches
plugins: fh-pytest-0.3.1
collected 4 items
test_pydantic_model.py .FF.                                              [100%]
=================================== FAILURES ===================================
_______________________ test_private_attr_generic_bound ________________________
o = Outer(a=GenBound[Regular](value=Regular(value=8)), b=GenT[int](value=42), c=RegGen(value=Regular(value=8)))
regular = Regular(value=8)
    def test_private_attr_generic_bound(o: Outer, regular: Regular):
>       assert o.a._privateattr == regular
E       assert None == Regular(value=8)
E        +  where None = GenBound[Regular](value=Regular(value=8))._privateattr
E        +    where GenBound[Regular](value=Regular(value=8)) = Outer(a=GenBound[Regular](value=Regular(value=8)), b=GenT[int](value=42), c=RegGen(value=Regular(value=8))).a
test_pydantic_model.py:77: AssertionError
______________________ test_private_attr_generic_unbound _______________________
o = Outer(a=GenBound[Regular](value=Regular(value=8)), b=GenT[int](value=42), c=RegGen(value=Regular(value=8)))
a = GenBound(value=Regular(value=8)), b = GenT(value=42)
c = RegGen(value=Regular(value=8)), regular = Regular(value=8)
    def test_private_attr_generic_unbound(o: Outer, a: GenBound[Regular], b: GenT[int], c: RegGen[Regular],
                                       regular: Regular):
>       assert o.b._privateattr == 42
E       assert None == 42
E        +  where None = GenT[int](value=42)._privateattr
E        +    where GenT[int](value=42) = Outer(a=GenBound[Regular](value=Regular(value=8)), b=GenT[int](value=42), c=RegGen(value=Regular(value=8))).b
test_pydantic_model.py:81: AssertionError
=========================== short test summary info ============================
FAILED test_pydantic_model.py::test_private_attr_generic_bound - assert None ...
FAILED test_pydantic_model.py::test_private_attr_generic_unbound - assert Non...
========================= 2 failed, 2 passed in 0.34s ==========================