express-query-parser2


A parser helps you parse request for your express server. You may usually encounter some ``req.query` issues like parsing `'null'`, `'true'` and any numbered string. This parser converts them to the right type.

- Forked from express-query-parser
- ✅ Full Express v5 compatibility - Works seamlessly with both Express v4 and v5
- ✅ TypeScript support - Written in TypeScript with full type definitions
- ✅ Zero breaking changes - Drop-in replacement for the original package

Scenarios

$3

`js
// GET http://localhost/?a=null&b=true&c[d]=false&c[e]=3.14

// without this parser
req.query = {a: 'null', b: 'true', c: {d: 'false', e: '3.14'}}

// with this parser
req.query = {a: null, b: true, c: {d: false, e: 3.14}}
`

$3

`js
// GET http://localhost/?a[]=null&a[]=false

// without this parser
req.query = {a: ['null', 'false']}

// with this parser
req.query = {a: [null, false]}
`

Express v5 Compatibility

This package is fully compatible with both Express v4 and Express v5. It automatically detects the Express version and uses the appropriate method to parse query parameters:

- Express v4: Direct assignment to req.query
- Express v5: Property descriptor override (respects Express v5's read-only req.query)

Features

- Parse your query for null / boolean / undefined
- Support nested query
- Support array
- Support numbered string convert
- Full Express v4 and v5 compatibility
- TypeScript support with full type definitions

$3

You can install via Yarn or npm

`bash
yarn add express-query-parser2
`

`bash
npm install express-query-parser2
`

$3

- Express: v4.17.1+ and v5.0.0+
- Node.js: v14+ (follows Express requirements)
- TypeScript: v4.0+ (optional, includes full type definitions)

Usage

$3

`js
import { queryParser } from 'express-query-parser2'
import express from 'express'

const app = express()

// For nested object support (user[name]=john -> {user: {name: 'john'}})
// Set query parser to 'extended' before using the middleware
app.set('query parser', 'extended')

app.use(
queryParser({
parseNull: true,
parseUndefined: true,
parseBoolean: true,
parseNumber: true
})
)
`

$3

`js
const { queryParser } = require('express-query-parser2')
const express = require('express')

const app = express()

// For nested object support
app.set('query parser', 'extended')

app.use(queryParser())
`

$3

To parse nested query parameters like user[name]=john into {user: {name: 'john'}}, you must configure Express to use the extended query parser:

`js
app.set('query parser', 'extended')
`

Without this setting, Express uses the simple query parser which keeps bracket notation as literal keys: {'user[name]': 'john'}.

Config Options

| field | desc | type | default |
|---|---|---|---|
| parseNull | convert all `"null"` to `null` | `boolean` | `true` |
| parseUndefined | convert all `"undefined"` to `undefined` | `boolean` | `true` |
| parseBoolean | convert all `"true"` to `true` and `"false"` to `false` | `boolean` | `true` |
| parseNumber | convert all numbered string to int and float | `boolean` | `true` |

---

Local Development and Contributing

I am more than happy to accept PRs for bugs, improvements or new features.
Developing your own changes locally is easy, you just need to clone the repo

`bash
git clone git@github.com/reediculous456/express-query-parser.git
`

Then navigate to the project folder

`bash

cd express-query-parser
`

and install the dependencies with either npm or yarn

`bash
npm i
`

`bash
yarn
`

Tests can be ran with the test script

`bash
npm run test
`

`bash
yarn test
``