def test_fields_can_fail_to_coerce_values():
# Given that I have a Field that allows coercions
field = Field(annotation=int, allow_coerce=True)
# When I call its validate method with a value that cannot be coerced
with pytest.raises(FieldValidationError) as e_data:
field.validate("invalid")
assert e_data.value.message == "value could not be coerced to int"
def test_fields_with_optional_unions(annotation, value, expected):
field = Field(annotation=annotation)
field.select_validator()
assert field.validate(value) == expected