data-spec-validator 0.1.0

simple validation tool for API

data-spec-validator

Why

• To get rid of code snippet like these (... cumbersome and tedious validation)

def do_something(params):
    val_a_must_int = params.get('a', 0)
    val_b_must_be_non_empty_list = params.get('b', [])
    # if key c presents, value c must be a date string between '2000-01-01' to '2020-01-01'
    val_c_might_be_none = params.get('c', None)

    # check type
    if type(val_a_must_int) != int:
      raise XXX

    # check type & value
    if type(val_b_must_list) != list or len(val_b_must_be_non_empty_list) == 0:
      raise XXX

    # if value exists, check its value
    if val_c_might_be_none is not None:
        date_c = datetime.strptime(val_c_might_be_present, '%Y-%m-%d')
        date_20000101 = datetime.date(2000, 1, 1)
        date_20200101 = datetime.date(2020, 1, 1)
        if not (date_20000101 <= date_c <= date_20200101):
          raise XXX
    ...
    # do something actually

Quick Example

• Do validate_data_spec directly wherever you like (see test_spect.py for more)

from spec import INT, DIGIT_STR, ONE_OF, OPTIONAL, Checker, CheckerOP, validate_data_spec

class SomeSpec:
    field_a = Checker([INT])
    field_b = Checker([DIGIT_STR, OPTIONAL], op=CheckerOP.ANY)

some_data = dict(field_a=3, field_b='4', field_c=[1,2])
validate_data_spec(some_data, SomeSpec) # return True

some_data = dict(field_a=4)
validate_data_spec(some_data, SomeSpec) # return True

some_data = dict(field_a='3')
validate_data_spec(some_data, SomeSpec) # raise Exception

some_data = dict(field_a='3')
validate_data_spec(some_data, SomeSpec, nothrow=True) # return False

class AnotherSpec:
    field = Checker([ONE_OF], extra={ONE_OF: [1, '2', [3, 4], {'5': 6}]})

another_data = dict(field=[3, 4])
validate_data_spec(another_data, AnotherSpec) # return True

another_data = dict(field='4')
validate_data_spec(another_data, AnotherSpec) # raise Exception

• Decorate a method with data_spec_validation, the method must meet one of the following requirements.
  1. Has a WSGIRequest(django.core.handlers.wsgi.WSGIRequest) attribute.
  2. The 2nd argument of the method is a rest_framework.request.Request instance.

from rest_framework.views import APIView

from decorator import data_spec_validation
from spec import UUID, EMAIL, Checker

class SomeViewSpec:
  param_a = Checker([UUID])
  param_b = Checker([EMAIL])

class SomeView(APIView):
    @data_spec_validation(SomeViewSpec)
    def get(self, request):
        pass

Test

python -m unittest test.test_spec