picoquery

A lightweight query string parser/stringifier with support for nesting and some configurability.

Built on top of fast-querystring.

Install

npm i -S picoquery

CommonJS vs ESM

2.x and above are ESM only (i.e. your project will need type: "module" in the package.json).

If you cannot yet move to ESM, you may continue to use 1.x which will still receive non-breaking changes, backported from main.

Usage

Parsing a query string:

import {parse} from 'picoquery';

parse('foo.bar=abc&baz=def');

/*
  {
    foo: {
      bar: 'abc'
    },
    baz: 'def'
  }
*/

Stringifying an object:

import {stringify} from 'picoquery';

stringify({
  foo: {
    bar: 123
  }
});

/*
foo.bar=123
*/

API

stringify(object[, options])

Converts the given object into a query string, optionally with configured options.

parse(str[, options])

Parses the given query string into an object, optionally with configured options.

Options

Default options

The default options are as follows:

{
  nesting: true,
  nestingSyntax: 'dot',
  arrayRepeat: false,
  arrayRepeatSyntax: 'repeat',
  delimiter: '&'
}

nesting

When true, nested objects are supported.

For example, when parsing:

parse('foo.bar=baz', {nesting: true});

// {foo: {bar: 'baz'}}

When stringifying:

stringify({foo: {bar: 'baz'}}, {nesting: true});

// foo.bar=baz

This also results in arrays being supported:

parse('foo.0=bar', {nesting: true});
// {foo: ['bar']}

stringify({foo: ['bar']}, {nesting: true});
// foo.0=bar

nestingSyntax

Sets which style of nesting syntax should be used. The choices are:

• dot (e.g. foo.bar=baz)
• index (e.g. foo[bar]=baz)
• js (e.g. foo.bar[0]=baz, i.e. arrays are indexed and properties are dotted)

arrayRepeat

If true, this will treat repeated keys as arrays.

For example:

parse('foo=x&foo=y', {arrayRepeat: true});
// {foo: ['x', 'y']}

stringify({foo: ['x', 'y']}, {arrayRepeat: true});
// foo=x&foo=y

arrayRepeatSyntax

Sets which style of array repetition syntax should be used. The choices are:

• bracket (e.g. foo[]=x&foo[]=y)
• repeat (e.g. foo=x&foo=y)

delimiter

Sets the delimiter to be used instead of &.

For example:

parse('foo=x;bar=y', {delimiter: ';'});
// {foo: 'x', bar: 'y'}

stringify({foo: 'x', bar: 'y'}, {delimiter: ';'});
// foo=x;bar=y

valueDeserializer

Can be set to a function which will be used to deserialize each value during parsing.

It will be called with the value and the already deserialized key (i.e. (value: string, key: PropertyKey) => *).

For example:

parse('foo=300', {
  valueDeserializer: (value) => {
    const asNum = Number(value);
    return Number.isNaN(asNum) ? value : asNum;
  }
});

// {foo: 300}

keyDeserializer

Can be set to a function which will be used to deserialize each key during parsing.

It will be called with the key from the query string (i.e. (key) => PropertyKey).

For example:

parse('300=foo', {
  keyDeserializer: (key) => {
    const asNum = Number(key);
    return Number.isNaN(asNum) ? key : asNum;
  }
});

// {300: 'foo'}

shouldSerializeObject

Can be set to a function which determines if an object-like value should be serialized instead of being treated as a nested object.

All non-object primitives will always be serialized.

For example:

// Assuming `StringifableObject` returns its constructor value when `toString`
// is called.
stringify({
  foo: new StringifiableObject('test')
}, {
  shouldSerializeObject(val) {
    return val instanceof StringifableObject;
  },
  valueSerializer: (value) => {
    return String(value);
  }
});

// foo=test

If you want to fall back to the default logic, you can import the default function:

import {defaultShouldSerializeObject, stringify} from 'picoquery';

stringify({
  foo: new StringifiableObject('test')
}, {
  shouldSerializeObject(val) {
    if (val instanceof StringifableObject) {
      return true;
    }
    return defaultShouldSerializeObject(val);
  }
});

valueSerializer

Can be set to a function which will be used to serialize each value during stringifying.

It will be called with the value and the key (i.e. (value: unknown, key: PropertyKey) => string).

For example:

stringify({foo: 'bar'}, {
  valueSerializer: (val) => String(val) + String(val)
});

// foo=barbar

Note that you can import the default serializer if you only want to handle some cases.

For example:

import {defaultValueSerializer, stringify} from 'picoquery';

stringify({foo: 'bar'}, {
  valueSerializer: (val, key) => {
    if (val instanceof Date) {
      return val.toISOString();
    }

    // Call the original serializer otherwise
    return defaultValueSerializer(val, key);
  }
});

Benchmarks

IMPORTANT: there are a few things to take into account with these benchmarks:

• fast-querystring is not capable of parsing or stringifying nested objects, so the results are incomparible (but here as reference)
• all libraries have their own level of configurability. It will be possible to increase perf in each of them by disabling various features, but these are just the 'happy path'

Parse

Benchmark: Basic (no nesting)
┌─────────┬─────────────────────────────────┬─────────────┬────────────────────┬──────────┬─────────┐
│ (index) │ Task Name                       │ ops/sec     │ Average Time (ns)  │ Margin   │ Samples │
├─────────┼─────────────────────────────────┼─────────────┼────────────────────┼──────────┼─────────┤
│ 0       │ 'picoquery'                     │ '2,393,539' │ 417.79130492907393 │ '±0.42%' │ 1196770 │
│ 1       │ 'qs'                            │ '382,933'   │ 2611.4212945313157 │ '±1.04%' │ 191467  │
│ 2       │ 'fast-querystring (no nesting)' │ '2,633,148' │ 379.77342802356833 │ '±1.58%' │ 1316575 │
└─────────┴─────────────────────────────────┴─────────────┴────────────────────┴──────────┴─────────┘
Benchmark: Dot-syntax nesting
┌─────────┬─────────────────────────────────┬─────────────┬───────────────────┬──────────┬─────────┐
│ (index) │ Task Name                       │ ops/sec     │ Average Time (ns) │ Margin   │ Samples │
├─────────┼─────────────────────────────────┼─────────────┼───────────────────┼──────────┼─────────┤
│ 0       │ 'picoquery'                     │ '1,406,039' │ 711.2176054736389 │ '±0.56%' │ 703020  │
│ 1       │ 'qs'                            │ '205,611'   │ 4863.536155478235 │ '±0.98%' │ 102806  │
│ 2       │ 'fast-querystring (no nesting)' │ '2,588,560' │ 386.3151031345139 │ '±0.66%' │ 1294281 │
└─────────┴─────────────────────────────────┴─────────────┴───────────────────┴──────────┴─────────┘

Stringify

Benchmark: Basic (no nesting)
┌─────────┬─────────────────────────────────┬─────────────┬────────────────────┬──────────┬─────────┐
│ (index) │ Task Name                       │ ops/sec     │ Average Time (ns)  │ Margin   │ Samples │
├─────────┼─────────────────────────────────┼─────────────┼────────────────────┼──────────┼─────────┤
│ 0       │ 'picoquery'                     │ '4,163,092' │ 240.20605684139227 │ '±0.16%' │ 2081547 │
│ 1       │ 'qs'                            │ '843,630'   │ 1185.352608720127  │ '±0.76%' │ 421816  │
│ 2       │ 'fast-querystring (no nesting)' │ '3,795,565' │ 263.46536774751036 │ '±0.24%' │ 1897783 │
└─────────┴─────────────────────────────────┴─────────────┴────────────────────┴──────────┴─────────┘
Benchmark: Dot-syntax nesting
┌─────────┬─────────────────────────────────┬─────────────┬────────────────────┬──────────┬─────────┐
│ (index) │ Task Name                       │ ops/sec     │ Average Time (ns)  │ Margin   │ Samples │
├─────────┼─────────────────────────────────┼─────────────┼────────────────────┼──────────┼─────────┤
│ 0       │ 'picoquery'                     │ '1,768,770' │ 565.3644818387182  │ '±1.08%' │ 884387  │
│ 1       │ 'qs'                            │ '332,254'   │ 3009.743667534287  │ '±1.38%' │ 166128  │
│ 2       │ 'fast-querystring (no nesting)' │ '7,227,031' │ 138.36940410118828 │ '±1.15%' │ 3613517 │
└─────────┴─────────────────────────────────┴─────────────┴────────────────────┴──────────┴─────────┘

License

MIT