Json

Warning

The to_json method has been deprecated and will be removed in a future releases. Use to_dict instead

Generating dynamic json object based on model. This is one of the most powerful feature of using models

Generating json based on model

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Let's imagine that we have a user object, and we need to get this object with random values each time

{
  "id": "3fa85f64-5717-4562-b3fc-2c963f66afa6",
  "username": "some random username",
  "email": "some random email"
}

So let's create a model which will generate us json above

Note

Id should be dynamic value. Usually when we write auto tests, we use dynamic values. Just like our API can't always accept static values, and vice versa they must be unique each time

import uuid

from models_manager import Model, Field
from models_manager.utils import random_string


class User(Model):
    id = Field(default=uuid.uuid4, json='id')
    username = Field(default=random_string, json='username')
    email = Field(default=random_string, json='email')

Let's see what's going on here

import uuid

from models_manager.utils import random_string

callable(uuid.uuid4)  # True
callable(random_string)  # True

callable(uuid.uuid4())  # False 
callable(random_string())  # False 

In this case, uuid4, random_string are callable objects. When generating json, these objects will be called and return values will be obtained from them

Let's try to use our user model and generate random json

import uuid

from models_manager import Model, Field
from models_manager.utils import random_string


class User(Model):
    id = Field(default=uuid.uuid4, json='id')
    username = Field(default=random_string, json='username')
    email = Field(default=random_string, json='email')


User.manager.to_json
{
    'id': '992ae8a2-ab6d-4d16-a7fd-e009bdcbff4c',
    'username': 'P8aNC414bqfSZEyUVpgZZQt',
    'email': 'UDxG3bKhvlLuM8n1LFCtfbZqwlKihogkL6BM8gfVIVk28'
}

User.manager.to_json
{
    'id': 'b3a02f98-7691-4a30-a42d-a1a3c600b584',
    'username': 'XUzl4QLP5mENis0tadeqacSSHf0vwaySeGQgV7S64R2M',
    'email': 'h1OnsjE5s1UXwTeEpuB5GbPPLF8'
}

Now we get random json values every time we call the to_json method

Generating negative json based on model

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Let's now imagine that we need to generate a negative json to test for an error in our API

Note

To generate negative json, we need to describe the fields in our model in more detail. This is necessary to more accurately generate negative json

Now we will extend our model and add new field attributes to it.

Imagine that the business logic of our product requests:

• id not null
• username should be up to 100 symbols, might be null
• email should be up to 70 symbols, not null

Let's describe it in our model

import uuid

from models_manager import Model, Field
from models_manager.utils import random_string


class User(Model):
    id = Field(default=uuid.uuid4, json='id', null=False)
    username = Field(default=random_string, json='username', max_length=100, null=True)
    email = Field(default=random_string, json='email', max_length=70, null=False)

Now let's try to generate negative json based on the model

import uuid

from models_manager import Model, Field
from models_manager.utils import random_string


class User(Model):
    id = Field(default=uuid.uuid4, json='id', null=False)
    username = Field(default=random_string, json='username', max_length=100, null=True)
    email = Field(default=random_string, json='email', max_length=70, null=False)


User.manager.to_negative_json()

{
    'id': None,
    'username': 'DV3CTqGsrXy95cXtCYniEE0BARnvmZTru0jhRFjEg7c4HZEsDHqo8TxkJbIh5FalDWNV2Cknu4OoeQ9CWyymfYvPUp9sXCvgbm13Eq1opfsVjiwbeIhTZo4gOyIbXDtbpg6vMHwuY1N',
    'email': None
}

Based on the business logic we described in the model, we generated a negative json that we can use in our test to test the negative scenario for the endpoint API

Overriding negative json provider

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You can make your own negative json generator. For that you have to override default negative json provider class. More info here