fast-qs

A tiny URL or URL query string parsing and stringifying library.

---

Installation

Install via npm

$ npm install fast-qs --save

Load fast-qs via classical <script> tag

<script src="https://cdn.jsdelivr.net/npm/fast-qs/dist/index.umd.js"></script>

or

<script src="https://cdn.jsdelivr.net/npm/fast-qs@2.0.1/dist/index.umd.js"></script>

use in window

// window.fastQs
fastQs.append
fastQs.escape
fastQs.parse
fastQs.stringify
fastQs.unescape

API

parse(str[, options])

The parse() method parses a URL query string (str) into a collection of key and value pairs.

interface ParseOptions {
  sep?: string;
  eq?: string;
  decodeURIComponent?: (str: string) => string;
  filter?: (key: string, val: any) => any;
  start?: number | string;
}

function parse(
  str: string,
  options?: ParseOptions
): Record<string, string | string[]>;

• str <string> The URL or URL query string to parse.
• options [ParseOptions]
  • sep The substring used to delimit key and value pairs in the query string. Default: '&'.
  • eq The substring used to delimit keys and values in the query string. Default: '='.
  • decodeURIComponent The function to use when decoding percent-encoded characters in the query string. Default: unescape().
  • filter The function to use when filtering keys and values from the query string.
  • start The index or substring of the str to start searching for the query string. Default: '?'.

For example:

import { parse } from 'fast-qs';

parse(null)
// => {}

parse('12342343')
// => {}

parse('a=1&b=2&c=3&d=&f=')
// => { a: '1', b: '2', c: '3', d: '', f: '' }

parse('&a=1&b=2&c=3&d=&f=')
// => { a: '1', b: '2', c: '3', d: '', f: '' }

parse('abcd1234&a=1&b=2&c=3&d=&f=')
// => { a: '1', b: '2', c: '3', d: '', f: '' }

parse('?a=1&a=2&a=3&d=&f=')
// => { a: ['1', '2', '3'], d: '', f: '' }

parse('https://www.npmjs.com/search?q=qs#hash')
// => { q: 'qs' }

parse('http://demo.com?a=1&a=2&b=1&c=1&hideTopbar=1&hideSidebar=1', {
  filter(key) {
    return key !== 'hideTopbar' && key !== 'hideSidebar';
  }
})
// => { a: ['1', '2'],  b: '1', c: '1' }

stringify(obj[, options])

The stringify() method produces a URL query string from a given obj by iterating through the object's "own properties".

export interface StringifyOptions {
  sep?: string;
  eq?: string;
  encodeURIComponent?: (str: string) => string;
  filter?: (key: string, val: any) => any;
}

function stringify(
  obj: Record<string, any>, 
  options?: StringifyOptions
): string;

• obj <Object> The object to serialize into a URL query string.
• options <StringifyOptions>
  • sep <string> The substring used to delimit key and value pairs in the query string. Default: '&'.
  • eq <string>. The substring used to delimit keys and values in the query string. Default: '='.
  • decodeURIComponent The function to use when decoding percent-encoded characters in the query string. Default: unescape().
  • encodeURIComponent <Function> The function to use when converting URL-unsafe characters to percent-encoding in the query string. Default: escape().
  • filter <Function> The function to use when filtering keys and values before adding them to the query string.

For example:

import { stringify } from 'fast-qs';

stringify(null)
// => {}
    
stringify({ a: 1, b: null, c: undefined, d: NaN, e: '' })
// => 'a=1&b=&c=&d=&e='

stringify({ a: '', c: ['\'1\'', '2', '3', NaN, undefined], f: null, '': 'null' })
// => 'a=&c=%271%27&c=2&c=3&c=&c=&f='

stringify({ a: { key: 'value', 'key2': 'value2' }, d: undefined, f: '' })
// => 'a=%7B%22key%22%3A%22value%22%2C%22key2%22%3A%22value2%22%7D&d=&f='

stringify({ a: () => { } })
// => 'a='

stringify({ a: [1, 2, 3, 4], b: 'test' }, {
  filter(key) {
    return key === 'a';
  }
})
// => 'a=1&a=2&a=3&a=4'

append(url, query[, options])

The append() method appends a URL query string or object(query) to the url.

export interface AppendOptions {
  sep?: string;
  eq?: string;
  encodeURIComponent?: (str: string) => string;
  filter?: (key: string, val: any) => any;
}

function append(
  url: string,
  query: string | object,
  opts?: AppendOptions
): string 

• url <string> The url to append the given query.
• query <string|object> The query to be appended to the url.
• options <StringifyOptions>
  • sep <string> The substring used to delimit key and value pairs in the query string. Default: '&'.
  • eq <string>. The substring used to delimit keys and values in the query string. Default: '='.
  • encodeURIComponent <Function> The function to use when converting URL-unsafe characters to percent-encoding in the query string. Default: escape().
  • filter <Function> The function to use when filtering keys and values before adding them to the query string.

For example:

import { append } from 'fast-qs';

append('http://demo.com', 'a=1&b=1&c=1');
// 'http://demo.com?a=1&b=1&c=1'

append('http://demo.com?test=1#hash', 'a=1&b=1&c=1');
// 'http://demo.com?test=1&a=1&b=1&c=1#hash'

append('http://demo.com', { a: 1, b: 1, c: 1 });
// 'http://demo.com?a=1&b=1&c=1'

append('http://demo.com?test=1#hash', { a: 1, b: 1, c: 1 });
// 'http://demo.com?test=1&a=1&b=1&c=1#hash'

append('http://demo.com', 'a=1&b=1&c=1&hideTopbar=1&hideSidebar=1', {
  filter(key) {
    return key !== 'hideTopbar' && key !== 'hideSidebar';
  },
})
// 'http://demo.com?a=1&b=1&c=1'

append('http://demo.com', { a: 1, b: 1, c: 1, hideTopbar: 1, hideSidebar: 1 }, {
  filter(key) {
    return key !== 'hideTopbar' && key !== 'hideSidebar';
  },
})
// 'http://demo.com?a=1&b=1&c=1'

escape(str)

• str <string>: The escape() method performs URL percent-encoding on the given str in a manner that is optimized for the specific requirements of URL query strings.

The escape() method is used by stringify() and is generally not expected to be used directly. It is exported primarily to allow application code to provide a replacement percent-encoding implementation if necessary by assigning escape() to an alternative function.

unescape(str)

• str <string>: unescape() method performs decoding of URL percent-encoded characters on the given str.

The unescape() method is used by parse() and is generally not expected to be used directly. It is exported primarily to allow application code to provide a replacement decoding implementation if necessary by assigning unescape() to an alternative function.

Test

$ npm test

Benchmark

$ npm run benchmark