[bug] Integer-like strings in validator defaults are incorrectly cast to integers

When specifying a default value for a validator of "+172800", dynaconf is casting the post-validation value to an integer 172800. This is still true after explicitly adding is_type_of=str to the validator. Interestingly enough, performing another validation after this point fails the validation.

Validator section including the offending validator

Example of the problem

Dynaconf shouldn’t be explicitly casting default values to another type when not explicitly conflicting with the is_type_of value.

Environment:

• OS: Fedora: 33
• Dynaconf Version: 3.1.4
• Frameworks in use: None

[rochacbruno]

@JacobCallahan actually TOML takes more integer prefixes in to account https://github.com/toml-lang/toml/blob/master/toml.abnf#L116-L129

We can resolve the case for + and - as suggested.

But in any case, @andressadotpy we need to update the docs adding some notes like

# toml conversions

All values in dynaconf are parsed using toml format, TOML tries to be smart
and infer the type of the settings variables, some variables will be automatically
converted to integer:


    FOO = "0x..."  # hexadecimal
    FOO = "0o..."  # Octal
    FOO = "0b..."  # Binary

All the cases are on toml specs https://github.com/toml-lang/toml/blob/master/toml.abnf

If you need to force a specific type casting there are 2 options.

1. Use double quoted for strings ex: `FOO = "'0x...'"  will be string.
2. Specify the type using `@`  ex: FOO = "@str 0x..."
   (available converters are `@int, @float, @bool, @json`)

[JacobCallahan]

@andressadotpy thanks for taking an interest in this issue! So the problem isn’t with the validator object itself, but when the default value is cast into a settings object.

In [1]: import dynaconf

In [2]: validator1 = dynaconf.validator.Validator("Testing", is_type_of=str, default="+172800")

In [3]: validator1.default
Out[3]: '+172800'

In [4]: settings = dynaconf.Dynaconf(validators=[validator1])

In [5]: settings.testing
Out[5]: 172800

In [6]: type(settings.testing)
Out[6]: int