pretty-format Travis build status

Stringify any JavaScript value.

Installation

$ npm install pretty-format

Usage

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:

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

Plugins

Pretty format also supports adding plugins:

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

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/lib/ReactTestRenderer');

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

prettyFormat(renderer.create(jsx).toJSON(), {
  plugins: [reactTestPlugin, reactElementPlugin]
});
// <h1>
//   Hello World
// </h1>