jsf - Faking JSON data from a schema

Andy Challis — Tue, 04 May 2021 04:47:08 +0000

Use jsf along with fake data generators to provide consistent and meaningful fake data for your system.

Main Features

Provides out of the box data generation from any JSON schema 📦
Extendable custom data providers using any lambda functions 🔗
Multi level state for dependant data (eg multiple objects sharing value, such as children with same surname) 🤓
Inbuilt validation of fake JSON produced ✅
In memory conversion from JSON Schema to Pydantic Models with generated examples 🤯
Seamless integration with FastAPI 🚀

Installation

$ pip install jsf

---> 100%

Usage

Basic 😊

from jsf import JSF

faker = JSF(
    {
        "type": "object",
        "properties": {
            "name": {"type": "string", "$provider": "faker.name"},
            "email": {"type": "string", "$provider": "faker.email"},
        },
        "required": ["name", "email"],
    }
)

fake_json = faker.generate()

Results in ...

{
    'name': 'Jesse Phillips', 
    'email': 'xroberson@hotmail.com'
}

From JSON file 📁

from jsf import JSF

faker = JSF.from_json("demo-schema.json")
fake_json = faker.generate()

Or run stright from the commandline...

Native install

jsf --schema src/tests/data/custom.json --instance wow.json

Docker

docker run -v $PWD:/data challisa/jsf jsf --schema /data/custom.json --instance /data/example.json

FastAPI Integration 🚀

Create a file main.py with:

from jsf import JSF
from fastapi import FastAPI

app = FastAPI(docs_url="/")
generator = JSF.from_json("custom.json")


@app.get("/generate", response_model=generator.pydantic())
def read_root():
    return generator.generate()

Run the server with:

$ uvicorn main:app --reload

INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [28720]
INFO:     Started server process [28722]
INFO:     Waiting for application startup.
INFO:     Application startup complete.

Navigate to http://127.0.0.1:8000 and check out your endpoint. Notice the following are all automatically created:

Schema with descriptions and examples
Example response
Data generation by clicking "try it out"

Forem: Andy Challis