Pretty print object

Stringify an object/array like JSON.stringify just without all the double-quotes

This is a fork of stringify-object, modified to inline the dependencies and make it compatible with ES5 out of the box.

Useful for when you want to get the string representation of an object in a formatted way.

It also handles circular references and lets you specify quote type.

Install

$ npm install @base2/pretty-print-object

Usage

const stringifyObject = require('@base2/pretty-print-object');

const obj = {
    foo: 'bar',
    'arr': [1, 2, 3],
    nested: {
        hello: "world"
    }
};

const pretty = stringifyObject(obj, {
    indent: '  ',
    singleQuotes: false
});

console.log(pretty);
/*
{
    foo: "bar",
    arr: [
        1,
        2,
        3
    ],
    nested: {
        hello: "world"
    }
}
*/

API

stringifyObject(input, [options])

Circular references will be replaced with "[Circular]".

Object keys are only quoted when necessary, for example, {'foo-bar': true}.

input

Type: Object Array

options

Type: Object

indent

Type: string
Default: \t

Preferred indentation.

singleQuotes

Type: boolean
Default: true

Set to false to get double-quoted strings.

filter(obj, prop)

Type: Function

Expected to return a boolean of whether to include the property prop of the object obj in the output.

transform(obj, prop, originalResult)

Type: Function
Default: undefined

Expected to return a string that transforms the string that resulted from stringifying obj[prop]. This can be used to detect special types of objects that need to be stringified in a particular way. The transform function might return an alternate string in this case, otherwise returning the originalResult.

Here's an example that uses the transform option to mask fields named "password":

const stringifyObject = require('@base2/pretty-print-object');

const obj = {
    user: 'becky',
    password: 'secret'
};

const pretty = stringifyObject(obj, {
    transform: (obj, prop, originalResult) => {
        if (prop === 'password') {
            return originalResult.replace(/\w/g, '*');
        }

        return originalResult;
    }
});

console.log(pretty);
/*
{
    user: 'becky',
    password: '******'
}
*/

inlineCharacterLimit

Type: number

When set, will inline values up to inlineCharacterLimit length for the sake of more terse output.

For example, given the example at the top of the README:

const stringifyObject = require('@base2/pretty-print-object');

const obj = {
    foo: 'bar',
    'arr': [1, 2, 3],
    nested: {
        hello: "world"
    }
};

const pretty = stringifyObject(obj, {
    indent: '  ',
    singleQuotes: false,
    inlineCharacterLimit: 12
});

console.log(pretty);
/*
{
    foo: "bar",
    arr: [1, 2, 3],
    nested: {
        hello: "world"
    }
}
*/

As you can see, arr was printed as a one-liner because its string was shorter than 12 characters.