Judge Jsen

judge-jsen is a tiny service intended to allow easy validation of JSON payloads using a provided JSON schema. It uses the excellent jsen validation tool.

Conventions

For judge-jsen to rule on a JSON payload it must first know what schema it is supposed to be using to validate against. This is done by requiring the root object of the JSON payload contain a $schema property with a url to the schema to be validated against.

example payload:

{
  "$schema": "https://raw.githubusercontent.com/statuswoe/judge-jsen/master/demo/demo.schema.json",
  "testString": "this is a test",
  "testInt": 12345
}

contents of schema at https://raw.githubusercontent.com/statuswoe/judge-jsen/master/demo/demo.schema.json

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "properties": {
    "$schema": {
      "type": "string"
    },
    "testString": {
      "type": "string"
    },
    "testInt": {
      "type": "integer"
    }
  },
  "additionalProperties": false,
  "required": [
    "$schema",
    "testString",
    "testInt"
  ]
}

Usage

Simply check out the source and run

npm install
node src/app.js

to start the service. Then you should be able to send POST requests to http://localhost:8000/validate to test the service.

curl -H "Accept: application/json" -H "Content-Type: application/json" --data-binary '{"$schema": "https://raw.githubusercontent.com/statuswoe/judge-jsen/master/demo/demo.schema.json", "testString": "this is a test", "testInt": 12345}' --compressed "http://localhost:8000/validate"

Responses to POST requests with valid schemas and a conforming JSON object should return a 200 response with a body similar to

data conforms to provided schema

Responses to POST requests with valid schemas but a non-conforming JSON object should return a 400 response with a body similar to

data does not conform to provided schema: [{"path":"testInt","keyword":"type"}]

where the error returns the first instance of non-conformity with the schema

Demo

An instance of this service may be available on heroku which can be used as a demo. To see the result you can use the following curl request:

curl -H "Accept: application/json" -H "Content-Type: application/json" --data-binary '{"$schema": "https://raw.githubusercontent.com/statuswoe/judge-jsen/master/demo/demo.schema.json", "testString": "this is a test", "testInt": 12345}' --compressed "https://judge-jsen.herokuapp.com/validate"

Notes

Currently the service only supports dereferenced JSON schemas
This project is still in the early stages of development