@ava/pretty-format 

> Stringify any JavaScript value.

- Supports all built-in JavaScript types
- Blazingly fast (similar performance to v8's JSON.stringify and significantly faster than Node's util.format)
- Plugin system for extending with custom types (i.e. ReactTestComponent)

Installation

``sh
$ npm install @ava/pretty-format
`

Usage

`js
var prettyFormat = require('pretty-format');

var obj = { property: {} };
obj.circularReference = obj;
obj[Symbol('foo')] = 'foo';
obj.map = new Map();
obj.map.set('prop', 'value');
obj.array = [1, NaN, Infinity];

console.log(prettyFormat(obj));
`

Result:

`js
Object {
"property": Object {},
"circularReference": [Circular],
"map": Map {
"prop" => "value"
},
"array": Array [
1,
NaN,
Infinity
],
Symbol(foo): "foo"
}
`

#### Type Support

Object, Array, ArrayBuffer, DataView, Float32Array, Float64Array, Int8Array, Int16Array, Int32Array, Uint8Array, Uint8ClampedArray, Uint16Array, Uint32Array, arguments, Boolean, Date, Error, Function, Infinity, Map, NaN, null, Number, RegExp, Set, String, Symbol, undefined, WeakMap, WeakSet

$3

`js
console.log(prettyFormat(object));
console.log(prettyFormat(object, options));
`

Options:

* callToJSON

Type: boolean, default: true

Call toJSON() on passed object.
* indent

Type: number, default: 2

Number of spaces for indentation.
* maxDepth

Type: number, default: Infinity

Print only this number of levels.
* min

Type: boolean, default: false

Print without whitespace.
* plugins

Type: array, default: []

Plugins (see the next section).
* printFunctionName

Type: boolean, default: true

Print function names or just [Function].
* escapeRegex

Type: boolean, default: false

Escape special characters in regular expressions.
* highlight

Type: boolean, default: false

Highlight syntax for terminal (works only with ReactTestComponent and ReactElement plugins.
* theme

Type: object, default: {tag: 'cyan', content: 'reset'...}

Syntax highlight theme.

Uses ansi-styles colors + reset for no color.

Available types: tag, content, prop and value.

$3

Pretty format also supports adding plugins:

`js
var fooPlugin = {
test: function(val) {
return val && val.hasOwnProperty('foo');
},
print: function(val, print, indent) {
return 'Foo: ' + print(val.foo);
}
};

var obj = { foo: { bar: {} } };

prettyFormat(obj, {
plugins: [fooPlugin]
});
// Foo: Object {
// "bar": Object {}
// }
`

#### ReactTestComponent and ReactElement plugins

`js
var prettyFormat = require('pretty-format');
var reactTestPlugin = require('pretty-format/plugins/ReactTestComponent');
var reactElementPlugin = require('pretty-format/plugins/ReactElement');

var React = require('react');
var renderer = require('react-test-renderer');

var jsx = React.createElement('h1', null, 'Hello World');

prettyFormat(renderer.create(jsx).toJSON(), {
plugins: [reactTestPlugin, reactElementPlugin]
});
//


// Hello World
//


``