fast-json-stringify

fast-json-stringify  

fast-json-stringify is x1-5 times faster than JSON.stringify(). It is particularly suited if you are sending small JSON payloads, the advantages reduces on large payloads.

Benchmarks:

JSON.stringify array x 3,500 ops/sec ±0.91% (85 runs sampled)
fast-json-stringify array x 4,456 ops/sec ±1.68% (87 runs sampled)
JSON.stringify long string x 13,395 ops/sec ±0.88% (91 runs sampled)
fast-json-stringify long string x 95,488 ops/sec ±1.04% (90 runs sampled)
JSON.stringify short string x 5,059,316 ops/sec ±0.86% (92 runs sampled)
fast-json-stringify short string x 12,219,967 ops/sec ±1.16% (91 runs sampled)
JSON.stringify obj x 1,763,980 ops/sec ±1.30% (88 runs sampled)
fast-json-stringify obj x 5,085,148 ops/sec ±1.56% (89 runs sampled)

Example

const fastJson = require('fast-json-stringify')
const stringify = fastJson({
  title: 'Example Schema',
  type: 'object',
  properties: {
    firstName: {
      type: 'string'
    },
    lastName: {
      type: 'string'
    },
    age: {
      description: 'Age in years',
      type: 'integer'
    },
    reg: {
      type: 'string'
    }
  }
})

console.log(stringify({
  firstName: 'Matteo',
  lastName: 'Collina',
  age: 32,
  reg: /"([^"]|\\")*"/
}))

API

fastJsonStringify(schema)

Build a stringify() function based on jsonschema.

Supported types:

• 'integer'
• 'number'
• 'array'
• 'object'
• 'boolean'
• 'null'

And nested ones, too.

Specific use cases

Instance	Serialized as
Date	string via toISOString()
RegExp	string

Required

You can set specific fields of an object as required in your schema, by adding the field name inside the required array in your schema.
Example:

const schema = {
  title: 'Example Schema with required field',
  type: 'object',
  properties: {
    nickname: {
      type: 'string'
    },
    mail: {
      type: 'string'
    }
  },
  required: ['mail']
}

If the object to stringify has not the required field(s), fast-json-stringify will throw an error.

Missing fields

If a field is present in the schema (and is not required) but it is not present in the object to stringify, fast-json-stringify will not write it in the final string.
Example:

const stringify = fastJson({
  title: 'Example Schema',
  type: 'object',
  properties: {
    nickname: {
      type: 'string'
    },
    mail: {
      type: 'string',
      required: true
    }
  }
})

const obj = {
  mail: '[e-mail]'
}

console.log(stringify(obj)) // '{"mail":"[e-mail]"}'

Acknowledgements

This project was kindly sponsored by nearForm.

License

MIT

Similar packages

Other packages similar to fast-json-stringify

json-stringify-safe

json-stringify-safe is a package that provides a safer version of JSON.stringify by handling circular references gracefully. While it focuses on safety and preventing errors during serialization, fast-json-stringify is optimized for speed and schema-based serialization.

ajv

ajv is a JSON schema validator that can also serialize JSON data. It is more focused on validation and supports a wide range of JSON schema features. While ajv can serialize data, fast-json-stringify is specifically optimized for high-performance serialization based on pre-compiled schemas.

superjson

superjson is a library that extends JSON serialization to support more JavaScript data types, such as Dates and Maps. It is designed to handle more complex data types, whereas fast-json-stringify focuses on speed and efficiency with a schema-based approach.