fastify-prettier

A simple and lightweight beautifier plugin for Fastify.

fastify-prettier has support of beautifying payloads via query parameter to make responses more readable for developers/humans. Decoratorprettier can also be used anywhere in the fastify server as the content beautifier. The plugin itself uses prettier under the hood and is capable of parsing/formatting anything that prettier can.

fastify-prettier uses onSend fastify hook to beautify the response payload before it gets sent.

Note: streams and buffers are excluded in beautification process. Note: Fastify v4 support is shipped with v2.0.0.

Installation

$ npm install fastify-prettier

Usage

const fastify = require('fastify')()
const fastifyPrettier = require('fastify-prettier')

fastify.register(
  fastifyPrettier,
  {
    fallbackOnError: false
  }
)

fastify.get('/', (req, reply) => {
  const obj = {
    blackLivesMatter: true,
    favSinger: 'Ahmet Kaya'
  }

  reply
    .type('application/json')
    .send(obj)
})

fastify.listen(3000, () => {
  console.log('Fastify server is running on port: 3000')
})

// -------------------------------

// http://localhost:3000 -> will print out below result
/*
{"blackLivesMatter":true,"favSinger":"Ahmet Kaya"}
*/

// http://localhost:3000?pretty=true -> will print out below result
/*
{
  "blackLivesMatter": true,
  "favSinger": "Ahmet Kaya"
}
*/

You are allowed to change the query parameter option.

fastify.register(
  fastifyPrettier,
  {
    query: {
      name: 'beautify',
      value: 'yes'
    }
  }
)

// -------------------------------

// http://localhost:3000 -> will print out below result
/*
{"blackLivesMatter":true,"favSinger":"Ahmet Kaya"}
*/

// http://localhost:3000?beautify=yes -> will print out below result
/*
{
  "blackLivesMatter": true,
  "favSinger": "Ahmet Kaya"
}
*/

You can enable beautification for all outgoing payloads regardless the query parameter.

fastify.register(
  fastifyPrettier,
  {
    alwaysOn: true
  }
)

// -------------------------------

// http://localhost:3000 -> will print out below result
/*
{
  "blackLivesMatter": true,
  "favSinger": "Ahmet Kaya"
}
*/

Usage of Decorator

Feel free to use prettier decorator which beautifies the given content through the provided options whenever you need.

const response = fastify.prettier(
  // content type can be: boolean, number, object, array, string
  content,
  // prettier options (please see: prettierOpts)
  { parser: 'html', htmlWhitespaceSensitivity: 'ignore' }
)

Options

| Name | Type | Default | Description | | --- | --- | --- | --- | | alwaysOn | boolean | false | To make all the payloads beautified in anyway | | fallbackOnError | boolean | true | If something bad happens, send the original payload. If its false, an error will be thrown | | overrideContentLength | boolean | true | Re-calculate content-length header for the beautified response | | query | object | { name: 'pretty', value: 'true' } | The query parameter that triggers the plugin to beautify the outgoing payload | | enableOnSendHook | boolean | true | Allow the plugin to get injected into fastify onSend hook to beautify outgoing responses. The prettier decorator can still be used even if that option is disabled | | prettierOpts | object | { tabWidth: 2, parser: 'json-stringify' } | Please take a look prettier official documentation for more information |