pretty-format
Stringify any JavaScript value.
Supports objects, arrays (and typed arrays and array buffers), arguments,
booleans, dates, errors, functions, Infinity
, maps, NaN
, null
, numbers,
regular expressions, sets, strings, symbols, undefined
, weak maps, weak
sets, and circular data structures.
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"
}
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 plugin
var prettyFormat = require('pretty-format');
var reactPlugin = require('pretty-format/plugins/ReactTestComponent');
var React = require('react');
var renderer = require('react/lib/ReactTestRenderer');
var jsx = React.createElement('h1', null, 'Hello World');
prettyFormat(renderer.create(jsx).toJSON(), {
plugins: [reactPlugin]
});
// <h1>
// Hello World
// </h1>