fs-ndjson

read and write NDJSON files (Newline Delimited JSON)

FYI

While NDJSON is often used for efficient streaming of JSON, it is also a good format for persisting and retreiving object data collections to and from disk. For example, NeDB uses the format.

See Also:

• http://ndjson.org/
• https://en.wikipedia.org/wiki/JSON_streaming#Line-delimited_JSON

API

The following fs-ndjson methods mirror the fs core module method APIs, however, the methods have been universalified so that you can use promises or callbacks for async.

• readFile
• readFileSync
• writeFile
• writeFileSync

BONUS: writeFile and writeFileSync will create the parent directory, if it does not already exist.

Installation

$ npm install --save fs-ndjson

Usage

Given /Users/tyler/project-mayhem/enemies.db contains

  {"name":"Equifax","location":"Atlanta, GA"}
  {"name":"Visa","location":"Foster City, CA"}

const fsNdjson = require('fs-ndjson');
 
// can return a promise
fsNdjson.readFile('/Users/tyler/project-mayhem/enemies.db').then(targets => {
  console.log(targets);
  // [
  //   {
  //     name: "Equifax",
  //     location: "Atlanta, GA"
  //   },
  //   {
  //     name: "Visa",
  //     location: "Foster City, CA"
  //   }
  // ]
});
 
// can use a callback
fsNdjson.readFile('/Users/tyler/project-mayhem/enemies.db', (err, enemies) => {
  if (err) throw err;
  console.log(enemies.length);
  // => 2
});
 
// can be used synchronously
let enemies = fsNdjson.readFileSync('/Users/tyler/project-mayhem/enemies.db');
 
// ******** BUT WAIT, THERE'S MORE! ******** //
// Not only does it read, but it writes too! //
 
// fsNdjson.writeFile     // use callback or promise
// fsNdjson.writeFileSync // does what you think it does

License

ISC © Buster Collings