json_parse.py

from dataclasses import dataclass
from dacite import from_dict
import dataclasses
import types
import json


@dataclass
class Bar:
    age: int


@dataclass
class Foo:
    name: str
    bar: Bar


def test_can_convert_from_dict():
    input = {'name': "Olly", 'bar': {'age': 12}}
    foo = Foo(**input)
    assert foo.name == "Olly"
    # assert foo.bar.age == 12  # DOES NOT WORK


def test_can_convert_to_json():
    input = Foo("Olly", Bar(12))
    asjson = json.dumps(input, cls=EnhancedJSONEncoder)
    assert asjson == r'{"name": "Olly", "bar": {"age": 12}}'


def test_can_convert_from_json_to_dict():
    input = r'{"name": "Olly", "bar": {"age": 12}}'
    as_dict = json.loads(input)
    assert as_dict['bar']['age'] == 12


def test_can_convert_from_json_to_dataclass():
    input = r'{"name": "Olly", "bar": {"age": 12}}'
    as_dict = json.loads(input)
    foo = from_dict(data_class=Foo, data=as_dict)
    assert foo.bar.age == 12


def test_can_convert_from_dict_to_dataclass():
    input = {'name': "Olly", 'bar': {'age': 12}}
    foo = from_dict(data_class=Foo, data=input)
    assert foo.bar.age == 12


class EnhancedJSONEncoder(json.JSONEncoder):
    def default(self, o):
        if dataclasses.is_dataclass(o):
            return dataclasses.asdict(o)
        return super().default(o)


def _dict_to_sns(d):
    return types.SimpleNamespace(**d)


def test_simplenamespace():
    my_dict = {'foo': 1, 'bar': {'baz': 2}}
    my_json = """ {"foo":1, "bar": {"baz": 2}} """
    out = json.loads(my_json, object_hook=_dict_to_sns)
    assert 2 == out.bar.baz
    out2 = types.SimpleNamespace(**my_dict)
    assert 1 == out2.foo
    # assert 2 == out2.bar.baz #won't work