agnostic-deref

Agnostic Dereference

Dereference JSON pointers in a JSON schemas with their true resolved values. A custom parsing function can be specified to support dereferencing of any file format. This has been forked from json-schema-deref.

Installation

npm install agnostic-deref

Overview

Let's say you have the following JSON Schema:

{
  "description": "Just some JSON schema.",
  "title": "Basic Widget",
  "type": "object",
  "definitions": {
    "id": {
      "description": "unique identifier",
      "type": "string",
      "minLength": 1,
      "readOnly": true
    }
  },
  "properties": {
    "id": {
      "$ref": "#/definitions/id"
    },
    "foo": {
      "$ref": "http://www.mysite.com/myschema.json#/definitions/foo"
    },
    "bar": {
      "$ref": "bar.json"
    }
  }
}

Sometimes you just want that schema to be fully expanded, with $ref's being their (true) resolved values:

{
  "description": "Just some JSON schema.",
  "title": "Basic Widget",
  "type": "object",
  "definitions": {
    "id": {
      "description": "unique identifier",
      "type": "string",
      "minLength": 1,
      "readOnly": true
    }
  },
  "properties": {
    "id": {
      "description": "unique identifier",
      "type": "string",
      "minLength": 1,
      "readOnly": true
    },
    "foo": {
      "description": "foo property",
      "readOnly": true,
      "type": "number"
    },
    "bar": {
      "description": "bar property",
      "type": "boolean"
    }
  }
}

This utility lets you do that:

var deref = require('agnostic-deref');
var myschema = require('schema.json');

var fullSchema = deref(myschema);

Agnostic Deference also allows refs of any format to be parsed via the options.parser function. This is useful if you specify your schemas in a non-JSON format, such as YAML:

# schema.yaml
---
  description: User
  title: User
  type: object

  properties:
    subschema:
      $ref: subschema.yaml

# subschema.yaml
---
  description: "Some subschema"
  properties:
    foo:
      type: string
    bar:
      type: object

const yaml = require('js-yaml');
const deref = require('agnostic-deref');
const fs = require('fs');

const schema = yaml.safeLoad(fs.readFileSync('schema.yaml'));

const fullSchema = deref(schema, { parser: yaml.safeLoad });

API Reference

deref(schema, options) ⇒ Object | Error

Derefs $ref's in JSON Schema to actual resolved values. Supports local, and file refs.

Kind: global function Returns: Object | Error - the deref schema oran instance of Error if error.

Param	Type	Description
schema	Object	The JSON schema
options	Object	options
options.baseFolder	String	the base folder to get relative path files from. Default is process.cwd()
options.failOnMissing	Boolean	By default missing / unresolved refs will be left as is with their ref value intact. If set to true we will error out on first missing ref that we cannot resolve. Default: false.
options.parser	Function	The function invoked to parse the contents of files located at each $ref. This defaults to JSON.parse.