Validate Json

.gitignore

*.pyc
*.swp
env

json_validator.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#Author: Tim Henderson
#Email: tadh@case.edu
#Copyright (C) 2012 All Rights Reserved
#For licensing see the LICENSE file in the top level directory.

class Checker(object):

    def __init__(self, checker):
        self.checker = checker

    def __call__(self, data):
        return self.checker(data)

    def __and__(a, b):
        if not isinstance(b, Checker): return NotImplemented
        def a_and_b(data):
            a_ok, a_err = a(data)
            b_ok, b_err = b(data)
            if a_err is None: a_err = list()
            if b_err is None: b_err = list()
            assert isinstance(a_ok, bool)
            assert isinstance(b_ok, bool)
            return (a_ok and b_ok), (a_err + b_err)
        return Checker(a_and_b)

    def __or__(a, b):
        if not isinstance(b, Checker): return NotImplemented
        def a_or_b(data):
            a_ok, a_err = a(data)
            b_ok, b_err = b(data)
            if a_err is None: a_err = list()
            if b_err is None: b_err = list()
            if a_ok: return True, list()
            if b_ok: return True, list()
            return False, (a_err + b_err)
        return Checker(a_or_b)

def checker(f):
    def decorator(*args, **kwargs):
        def wrapper(data):
            return f(data, *args, **kwargs)
        return Checker(wrapper)
    return decorator

@checker
def value_checker(data, value):
    if data != value:
        return False, [
            "'%s' is not equal to '%s'" % (str(data), str(value))]
    return True, list()

@checker
def type_checker(data, type):
    if not isinstance(data, type):
        return False, [
            "Object, '%s', not of type %s" % (repr(data), str(type))]
    return True, list()

@checker
def length_checker(data, length):
    if not hasattr(data, '__len__'):
        return False, ["Object, '%s', doesn't have a length" % (repr(data))]
    if len(data) != length:
        return False, [
            "Sequence, '%s', is not %d items long" % (str(data), int(length))]
    return True, list()

@checker
def max_length_checker(data, length):
    if not hasattr(data, '__len__'):
        return False, ["Object, '%s', doesn't have a length" % (repr(data))]
    if len(data) > length:
        return False, [
            "Sequence, '%s', greater than %d items long" % (str(data), int(length))]
    return True, list()

@checker
def min_length_checker(data, length):
    if not hasattr(data, '__len__'):
        return False, ["Object, '%s', doesn't have a length" % (repr(data))]
    if len(data) < length:
        return False, [
            "Sequence, '%s', less than %d items long" % (str(data), int(length))]
    return True, list()

def validate_json(schema, json_data):
    ''' Assert that d matches the schema
    @param d = the dictionary
    @param allow_none = allow Nones in d '''

    errors = list()

    def proc(v1, v2):
        '''process 2 values assert they are of the same type'''
        #print 'proc>', v1, v2
        if   isinstance(v1, dict):
            return procdict(v1, v2)
        elif isinstance(v1, list):
            return proclist(v1, v2)
        else:
            validator = v1
            if not hasattr(validator, '__call__'):
                errors.append(
                    "Expected schema item to be a callable got %s" % str(v1))
                return False
            ret = validator(v2)
            if not isinstance(ret, tuple):
                errors.append(
                    "Expected item validator to return a tuple got %s" %
                    str(ret))
                return False
            if len(ret) != 2:
                errors.append(
                    "Expected item validator to return 2 items got %s" %
                    str(ret))
                return False
            ok, err = ret
            #print ok, err
            if not ok:
                errors.extend(err)
                return False
            return True
    def proclist(t, d):
        '''process a list type'''
        if not isinstance(d, list):
            msg = ("Expected a <type 'list'> got %s" % type(d))
            errors.append(err)
            return False
        if len(t) != 1:
            errors.append(
                "Expected schema item to contain one element got %s" % str(t))
            return False
        v1 = t[0]
        acc = True
        for v2 in d:
            #print v1, v2
            r = proc(v1, v2)
            acc = acc and r
        return acc
    def procdict(t, d):
        '''process a dictionary type'''
        if not isinstance(d, dict):
            raise AssertionError, "Expected a <type 'dict'> got %s, '%s'"\
                                  % (type(d), str(d))
        tkeys = set(t.keys());
        dkeys = set(d.keys());
        acc = True
        if '__undefinedkeys__' in tkeys:
            v1 = t['__undefinedkeys__']
            for v2 in d.values():
                r = proc(v1, v2)
                acc = acc and r
        else:
            for k in tkeys:
                if k not in dkeys:
                    msg = (
                      'Expected name, "%s", in %s'
                    ) % (str(k), str(d))
                    errors.append(msg)
                    acc = False
            for k in dkeys:
                if k not in tkeys:
                    msg = (
                      'Unexpected name, "%s". The name must be in %s'
                    ) % (str(k), str(tkeys))
                    errors.append(msg)
                    acc = False
                else:
                    v1 = t[k]
                    v2 = d[k]
                    r = proc(v1, v2)
                    acc = acc and r
        return acc
    ok = proc(schema, json_data)
    return ok, errors

reqs.txt

nose==1.1.2

test_json_validator.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#Author: Tim Henderson
#Email: tadh@case.edu
#Copyright (C) 2012 All Rights Reserved
#For licensing see the LICENSE file in the top level directory.

from json_validator import validate_json
import json_validator as vlib

def test_one_item_valid():
    schema = {
        "name" : vlib.value_checker("value")
    }
    ok, errors = validate_json(schema, {"name":"value"})
    assert ok
    assert len(errors) == 0

def test_one_item_invalid():
    schema = {
        "name" : 
          lambda b: (
            (True, list()) 
              if (b == 'value') 
              else (False, ["'%s' is not equal to 'value'" % b]))
    }
    ok, errors = validate_json(schema, {"name":"vsdalue"})
    assert not ok
    assert len(errors) == 1
    assert errors[0] == "'vsdalue' is not equal to 'value'"

def test_one_item_no_validator():
    schema = {
        "name" : "value"
    }
    ok, errors = validate_json(schema, {"name":"vsdalue"})
    assert not ok
    assert len(errors) == 1
    assert errors[0] == 'Expected schema item to be a callable got value'

def test_one_item_validator_returns_one_item():
    schema = {
        "name" : 
          lambda b: (True if (b == 'value') else False)
    }
    ok, errors = validate_json(schema, {"name":"vsdalue"})
    assert not ok
    assert len(errors) == 1
    assert errors[0] == 'Expected item validator to return a tuple got False'

def test_one_item_validator_returns_three_items():
    schema = {
        "name" : 
          lambda b: ((True, None, None) if (b == 'value') else (False, "asdf",
          "adfs"))
    }
    ok, errors = validate_json(schema, {"name":"vsdalue"})
    assert not ok
    assert len(errors) == 1
    assert errors[0] == "Expected item validator to return 2 items got (False, 'asdf', 'adfs')"

def test_list_one_item_valid():
    schema = [
      {
        "name" : vlib.value_checker("value")
      }
    ]
    ok, errors = validate_json(schema, [{"name":"value"}])
    assert ok
    assert len(errors) == 0

def test_list_three_items_valid():
    schema = [
      {
        "name" : vlib.value_checker("value")
      }
    ]
    ok, errors = validate_json(schema, [{"name":"value"}, {"name":"value"},
      {"name":"value"}])
    assert ok
    assert len(errors) == 0

def test_list_three_items_invalid():
    schema = [
      {
        "name" : vlib.value_checker("value")
      }
    ]
    ok, errors = validate_json(schema, [{"name":"vaque"}, {"name":"valqe"},
      {"name":"vqlue"}])
    assert not ok
    assert len(errors) == 3
    assert errors == ["'vaque' is not equal to 'value'", 
                      "'valqe' is not equal to 'value'", 
                      "'vqlue' is not equal to 'value'"]

def test_list_three_bare_items_valid():
    schema = [
        vlib.value_checker("value")
    ]
    ok, errors = validate_json(schema, ["value", "value", "value"])
    assert ok
    assert len(errors) == 0


def test_length_checker():
    schema = [
          vlib.length_checker(5)
    ]
    ok, errors = validate_json(schema, ["value", "value", "value"])
    assert ok
    assert len(errors) == 0

def test_type_checker():
    schema = [
          vlib.type_checker(basestring)
    ]
    ok, errors = validate_json(schema, ["value", "value", "value"])
    assert ok
    assert len(errors) == 0
 
def test_max_length_checker():
    schema = [
          vlib.max_length_checker(5)
    ]
    ok, errors = validate_json(schema, ["value", "value", "value"])
    assert ok
    assert len(errors) == 0

def test_max_length_checker_under():
    schema = [
          vlib.max_length_checker(5)
    ]
    ok, errors = validate_json(schema, ["valu"])
    assert ok
    assert len(errors) == 0

def test_max_length_checker_over():
    schema = [
          vlib.max_length_checker(5)
    ]
    ok, errors = validate_json(schema, ["values"])
    assert not ok
    assert len(errors) == 1
    assert errors == ["Sequence, 'values', greater than 5 items long"]

def test_min_length_checker():
    schema = [
          vlib.min_length_checker(5)
    ]
    ok, errors = validate_json(schema, ["value", "value", "value"])
    assert ok
    assert len(errors) == 0

def test_min_length_checker_under():
    schema = [
          vlib.min_length_checker(5)
    ]
    ok, errors = validate_json(schema, ["valu"])
    assert not ok
    assert len(errors) == 1
    assert errors == ["Sequence, 'valu', less than 5 items long"]

def test_min_length_checker_over():
    schema = [
          vlib.min_length_checker(5)
    ]
    ok, errors = validate_json(schema, ["values"])
    assert ok
    assert len(errors) == 0

def test_type_or_type_checker():
    schema = [
          vlib.type_checker(int) | vlib.type_checker(float)
    ]
    ok, errors = validate_json(schema, ["value", "value", "value"])
    assert not ok
    assert len(errors) == 6

def test_type_and_type_checker():
    schema = [
          vlib.type_checker(int) & vlib.type_checker(float)
    ]
    ok, errors = validate_json(schema, ["value", "value", "value"])
    assert not ok
    assert len(errors) == 6
    assert errors == [
        "Object, ''value'', not of type <type 'int'>", 
        "Object, ''value'', not of type <type 'float'>", 
        "Object, ''value'', not of type <type 'int'>", 
        "Object, ''value'', not of type <type 'float'>", 
        "Object, ''value'', not of type <type 'int'>", 
        "Object, ''value'', not of type <type 'float'>"]

def test_type_and_length_checker():
    schema = [
          vlib.type_checker(basestring) & vlib.length_checker(4)
    ]
    ok, errors = validate_json(schema, ["value"])
    assert not ok
    assert len(errors) == 1
    assert errors == ["Sequence, 'value', is not 4 items long"]

def test_type_or_length_checker():
    schema = [
          vlib.type_checker(basestring) | vlib.length_checker(4)
    ]
    ok, errors = validate_json(schema, ["value"])
    assert ok
    assert len(errors) == 0

def test_type_and_length_checker_both_true():
    schema = [
          vlib.type_checker(basestring) & vlib.length_checker(5)
    ]
    ok, errors = validate_json(schema, ["value"])
    assert ok
    assert len(errors) == 0