prettyoutput

What is prettyoutput?

The prettyoutput npm package is designed to format and print JavaScript objects in a visually appealing and readable way. It is particularly useful for debugging and logging purposes, as it helps developers quickly understand the structure and content of complex objects.

What are prettyoutput's main functionalities?

Basic Object Formatting

This feature allows you to format a basic JavaScript object into a more readable string format. The code sample demonstrates how to use prettyoutput to print a simple object.

const prettyoutput = require('prettyoutput');
const obj = { name: 'John', age: 30, city: 'New York' };
console.log(prettyoutput(obj));

Nested Object Formatting

This feature handles the formatting of nested objects, making it easier to visualize the structure of more complex data. The code sample shows how prettyoutput can be used to print an object with nested properties.

const prettyoutput = require('prettyoutput');
const nestedObj = { person: { name: 'John', age: 30 }, address: { city: 'New York', zip: '10001' } };
console.log(prettyoutput(nestedObj));

Array Formatting

This feature formats arrays, including those containing objects and other arrays. The code sample demonstrates how prettyoutput can be used to print an array with mixed content.

const prettyoutput = require('prettyoutput');
const arr = [1, 2, { name: 'John', age: 30 }, [3, 4]];
console.log(prettyoutput(arr));

Other packages similar to prettyoutput

prettyjson

The prettyjson package is another tool for formatting JSON data in a readable way. It offers similar functionality to prettyoutput but focuses specifically on JSON objects. It provides colorized output and supports custom indentation levels.

json-stringify-pretty-compact

This package provides a way to stringify JSON objects in a compact and pretty format. It is similar to prettyoutput in that it aims to make JSON data more readable, but it focuses on producing a compact output that still maintains readability.

cli-color

The cli-color package is a comprehensive tool for styling and formatting console output, including JSON objects. While it offers broader functionality beyond just pretty-printing objects, it can be used to achieve similar results to prettyoutput with additional customization options.

README

prettyoutput

Library to format js/json object into YAML style readable output. It's performance centric to be used as a logger formatter. It's currently 3 to 5 times quicker than util.inspect used by many loggers. It's available as a NodeJS library or a cli too.

Credits

This is based on the great work done on the project prettyjson

How to install

Via NPM:

$ npm install prettyoutput

Using it

It's pretty easy to use. Just have include it in your script and call it:

const prettyoutput = require('prettyoutput')

const data = {
  username: 'kic',
  url: 'https://github.com/keepitcool',
  projects: ['prettyoutput', '3m2tuio']
}

console.log(prettyoutput(data))

Output:

API

const prettyoutput = require('prettyoutput')
prettyoutput(data, options, indent)

Parameters are :

• {*} data : js or json object
• {Object} [options] : Optional. See options below
• {number} [indent] : Optional. Indent all output

Options are :

• {number} [indentationLength] : Length of indentation (in terms of space)
• {number} [maxDepth] : maximum sublevel of nested objects/arrays to output. Default: 3
• {boolean} [noColor] : disable colors. Default: false
• {colors} [colors] : Output colors. See below

Colors are :

• {string} [keys] : Objects keys color. Default: green
• {string} [dash] : Array prefixing dash ("- "). Default: green
• {string} [number] : Numbers color. Default: blue
• {string} [string] : Strings color. Default: no color
• {string} [true] : Boolean value 'true' color. Default: green
• {string} [false] : Boolean value 'false' color. Default: red
• {string} [null] : 'Null' color. Default: grey

Example using options :

const prettyoutput = require('prettyoutput')

const data = {
  username: 'kic',
  url: 'https://github.com/keepitcool',
  projects: ['prettyoutput', '3m2tuio']
}

const colors = {
  keys: 'blue',
  'null': 'red'
}

const options = {
  noColor: true,
  maxDepth: 5,
  colors: colors
};

console.log(prettyoutput(data, options, 2);

Cli usage

Command line tool support file param or stdin.

Usage:

$ prettyoutput package.json

This should output :

Command line options

It's possible to customize the output through some command line options:

# Indent 4, max depth 5, disable colors
$ prettyjson --indent=4 --depth=5 --noColor package.json

or

# Indent 4, max depth 5, disable colors
$ cat package.json | prettyjson --indent=4 --depth=5 --noColor

Benchmark

Project target logging, so performance is an issue. Currently, prettyoutput is 3 times quicker than util.inspect and 2.5 times quicker than prettyjson, the library it's inspired from.

To run benchmark, just run :

$ node benchmark/benchmark.js

Results :

LEVELS | KEYS | LOOPS | WEIGTHS
3      | 20   | 100   | serializable: 0.9    array: 0.3    object: 0.5    multilineString: 0.3    error: 0.2

NAME         | MIN                 | MAX                 | MEAN                | TOTAL
prettyoutput | 3 ms 133 µs 526 ns  | 42 ms 563 µs 146 ns | 4 ms 365 µs 617 ns  | 436 ms 561 µs 716 ns
prettyjson   | 9 ms 615 µs 703 ns  | 21 ms 441 µs 595 ns | 11 ms 447 µs 83 ns  | 1 s 144 ms 708 µs 348 ns
util.inspect | 10 ms 839 µs 974 ns | 24 ms 332 µs 545 ns | 12 ms 526 µs 168 ns | 1 s 252 ms 616 µs 884 ns


LEVELS | KEYS | LOOPS | WEIGTHS
4      | 20   | 100   | serializable: 0.9    array: 0.3    object: 0.5    multilineString: 0.3    error: 0.2

NAME         | MIN                 | MAX                  | MEAN                 | TOTAL
prettyoutput | 29 ms 966 µs 837 ns | 102 ms 170 µs 779 ns | 39 ms 502 µs 799 ns  | 3 s 950 ms 279 µs 972 ns
prettyjson   | 86 ms 731 µs 622 ns | 159 ms 166 µs 633 ns | 107 ms 813 µs 674 ns | 10 s 781 ms 367 µs 439 ns
util.inspect | 90 ms 942 µs 290 ns | 256 ms 995 µs 418 ns | 118 ms 794 µs 343 ns | 11 s 879 ms 434 µs 322 ns


LEVELS | KEYS | LOOPS | WEIGTHS
5      | 20   | 100   | serializable: 0.9    array: 0.3    object: 0.5    multilineString: 0.3    error: 0.2

NAME         | MIN                      | MAX                      | MEAN                     | TOTAL
prettyoutput | 616 ms 495 µs 243 ns     | 1 s 602 ms 965 µs 211 ns | 768 ms 761 µs 315 ns     | 76 s 876 ms 131 µs 544 ns
prettyjson   | 1 s 294 ms 734 µs 939 ns | 1 s 686 ms 600 µs 593 ns | 1 s 490 ms 394 µs 707 ns | 149 s 39 ms 470 µs 777 ns
util.inspect | 1 s 623 ms 160 µs 631 ns | 2 s 460 ms 983 µs 994 ns | 1 s 731 ms 699 µs 847 ns | 173 s 169 ms 984 µs 758 ns

Running Tests

To run the test suite first invoke the following command within the repo, installing the development dependencies:

$ npm install

then run the tests:

$ npm test