@apidevtools/json-schema-ref-parser
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Parse, Resolve, and Dereference JSON Schema $ref pointers
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# JSON Schema $Ref Parser
#### Parse, Resolve, and Dereference JSON Schema $ref pointers
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## Installation
Install using [npm](https://docs.npmjs.com/about-npm/):
```bash
npm install @apidevtools/json-schema-ref-parser
yarn add @apidevtools/json-schema-ref-parser
bun add @apidevtools/json-schema-ref-parser
```
## The Problem:
You've got a JSON Schema with `$ref` pointers to other files and/or URLs. Maybe you know all the referenced files ahead
of time. Maybe you don't. Maybe some are local files, and others are remote URLs. Maybe they are a mix of JSON and YAML
format. Maybe some of the files contain cross-references to each other.
```json
{
"definitions": {
"person": {
// references an external file
"$ref": "schemas/people/Bruce-Wayne.json"
},
"place": {
// references a sub-schema in an external file
"$ref": "schemas/places.yaml#/definitions/Gotham-City"
},
"thing": {
// references a URL
"$ref": "http://wayne-enterprises.com/things/batmobile"
},
"color": {
// references a value in an external file via an internal reference
"$ref": "#/definitions/thing/properties/colors/black-as-the-night"
}
}
}
```
## The Solution:
JSON Schema $Ref Parser is a full [JSON Reference](https://tools.ietf.org/html/draft-pbryan-zyp-json-ref-03)
and [JSON Pointer](https://tools.ietf.org/html/rfc6901) implementation that crawls even the most
complex [JSON Schemas](http://json-schema.org/latest/json-schema-core.html) and gives you simple, straightforward
JavaScript objects.
- Use **JSON** or **YAML** schemas — or even a mix of both!
- Supports `$ref` pointers to external files and URLs, as well
as [custom sources](https://apitools.dev/json-schema-ref-parser/docs/plugins/resolvers.html) such as databases
- Can [bundle](https://apitools.dev/json-schema-ref-parser/docs/ref-parser.html#bundlepath-options-callback) multiple
files into a single schema that only has _internal_ `$ref` pointers
- Can [dereference](https://apitools.dev/json-schema-ref-parser/docs/ref-parser.html#dereferencepath-options-callback)
your schema, producing a plain-old JavaScript object that's easy to work with
- Supports [circular references](https://apitools.dev/json-schema-ref-parser/docs/#circular-refs), nested references,
back-references, and cross-references between files
- Maintains object reference equality — `$ref` pointers to the same value always resolve to the same object
instance
- Compatible with Node LTS and beyond, and all major web browsers on Windows, Mac, and Linux
## Example
```javascript
import $RefParser from "@apidevtools/json-schema-ref-parser";
try {
await $RefParser.dereference(mySchema);
// note - by default, mySchema is modified in place, and the returned value is a reference to the same object
console.log(mySchema.definitions.person.properties.firstName);
// if you want to avoid modifying the original schema, you can disable the `mutateInputSchema` option
let clonedSchema = await $RefParser.dereference(mySchema, { mutateInputSchema: false });
console.log(clonedSchema.definitions.person.properties.firstName);
} catch (err) {
console.error(err);
}
```
For more detailed examples, please see the [API Documentation](https://apitools.dev/json-schema-ref-parser/docs/)
## Polyfills
If you are using Node.js < 18, you'll need a polyfill for `fetch`,
like [node-fetch](https://github.com/node-fetch/node-fetch):
```javascript
import fetch from "node-fetch";
globalThis.fetch = fetch;
```
## Browser support
JSON Schema $Ref Parser supports recent versions of every major web browser. Older browsers may
require [Babel](https://babeljs.io/) and/or [polyfills](https://babeljs.io/docs/en/next/babel-polyfill).
To use JSON Schema $Ref Parser in a browser, you'll need to use a bundling tool such
as [Webpack](https://webpack.js.org/), [Rollup](https://rollupjs.org/), [Parcel](https://parceljs.org/),
or [Browserify](http://browserify.org/). Some bundlers may require a bit of configuration, such as
setting `browser: true` in [rollup-plugin-resolve](https://github.com/rollup/rollup-plugin-node-resolve).
#### Webpack 5
Webpack 5 has dropped the default export of node core modules in favour of polyfills, you'll need to set them up
yourself ( after npm-installing them )
Edit your `webpack.config.js` :
```js
config.resolve.fallback = {
path: require.resolve("path-browserify"),
fs: require.resolve("browserify-fs"),
};
config.plugins.push(
new webpack.ProvidePlugin({
Buffer: ["buffer", "Buffer"],
}),
);
```
## API Documentation
Full API documentation is available [right here](https://apitools.dev/json-schema-ref-parser/docs/)
## Contributing
I welcome any contributions, enhancements, and
bug-fixes. [Open an issue](https://github.com/APIDevTools/json-schema-ref-parser/issues) on GitHub
and [submit a pull request](https://github.com/APIDevTools/json-schema-ref-parser/pulls).
#### Building/Testing
To build/test the project locally on your computer:
1. **Clone this repo**<br>
`git clone https://github.com/APIDevTools/json-schema-ref-parser.git`
2. **Install dependencies**<br>
`yarn install`
3. **Run the tests**<br>
`yarn test`
## License
JSON Schema $Ref Parser is 100% free and open-source, under the [MIT license](LICENSE). Use it however you want.
## Thanks
Thanks to these awesome contributors for their major support of this open-source project.
- [JonLuca De Caro](https://jonlu.ca)
- [Phil Sturgeon](https://philsturgeon.com)
- [Stoplight](https://stoplight.io/?utm_source=github&utm_medium=readme&utm_campaign=json_schema_ref_parser)