def test_decimal_float_precision() -> None:
    """https://github.com/pydantic/pydantic/issues/6807"""
    ta = TypeAdapter(Decimal)
    assert ta.validate_json('1.1') == Decimal('1.1')
    assert ta.validate_python(1.1) == Decimal('1.1')
    assert ta.validate_json('"1.1"') == Decimal('1.1')
    assert ta.validate_python('1.1') == Decimal('1.1')
    assert ta.validate_json('1') == Decimal('1')
    assert ta.validate_python(1) == Decimal('1')
https://github.com/pydantic/pydantic/issues/6807
tests/test_types.py