ldap-filter

0.3.3 verified Sat Apr 25 auth: no javascript

API for handling LDAP-style filters, originally derived from filter code in LDAPjs. Version 0.3.3 is the latest stable release. This package provides utilities to parse, serialize, and manipulate LDAP filter strings (e.g., RFC 4515). It is minimal and focused, suitable for server-side Node.js applications that need to handle LDAP filter syntax without the full LDAPjs library. Release cadence is low; no major updates since 2019.

Common errors

error Cannot find module 'ldap-filter' ↓

cause Package not installed or import path incorrect.

fix

npm install ldap-filter and use import { parseString } from 'ldap-filter'

error TypeError: ldap_filter_1.parseString is not a function ↓

cause Using require('ldap-filter') which returns a module with default export instead of named exports.

fix

Use import { parseString } from 'ldap-filter' or const { parseString } = await import('ldap-filter')

error SyntaxError: Unexpected token 'export' ↓

cause Project is not configured for ESM (e.g., CommonJS only).

fix

Add 'type': 'module' to package.json or use dynamic import().

Warnings

breaking Version 0.3.x drops support for Node.js < 0.8 ↓

fix Upgrade Node.js to >=0.8 or stick with older version 0.2.x

deprecated The parseString function may be deprecated in future versions in favor of a class method. ↓

fix Check future releases for migration guides; currently parseString still works.

gotcha Filter values are not escaped by default; manual escaping may be needed for special characters. ↓

fix Use `filter.attribute` and `filter.value` directly; consider encoding with encodeURIComponent if required.

gotcha The package does not validate filter string syntax; invalid filters may return unexpected objects. ↓

fix Validate input before parsing; use try-catch to handle potential parse errors.

Install

npm install ldap-filter

yarn add ldap-filter

pnpm add ldap-filter

Imports

parseString
wrong
```
const { parseString } = require('ldap-filter')
```
correct
```
import { parseString } from 'ldap-filter'
```
Package is ESM-only. CommonJS require will fail. Use dynamic import() if needed.

Filter

wrong

const Filter = require('ldap-filter').Filter

correct

import { Filter } from 'ldap-filter'

Filter is a base class, also a named export.

EqualityFilter
wrong
```
const EqualityFilter = require('ldap-filter').EqualityFilter
```
correct
```
import { EqualityFilter } from 'ldap-filter'
```
Also available: PresenceFilter, SubstringFilter, GreaterOrEqualFilter, LessOrEqualFilter, AndFilter, OrFilter, NotFilter, ApproxFilter.

Quickstart

Parses an LDAP filter string and builds filters programmatically, demonstrating EqualityFilter and boolean combinators.

import { parseString, EqualityFilter } from 'ldap-filter';

// Parse an LDAP filter string
const filter = parseString('(cn=John Doe)');
console.log(filter.constructor.name); // EqualityFilter
console.log(filter.attribute); // 'cn'
console.log(filter.value); // 'John Doe'
console.log(filter.toString()); // '(cn=John Doe)'

// Or build a filter programmatically
const eqFilter = new EqualityFilter({
  attribute: 'uid',
  value: 'jdoe'
});
console.log(eqFilter.toString()); // '(uid=jdoe)'

// Chain filters with boolean combinators
import { AndFilter, OrFilter } from 'ldap-filter';
const andFilter = new AndFilter({
  filters: [
    new EqualityFilter({ attribute: 'sn', value: 'Doe' }),
    new EqualityFilter({ attribute: 'givenName', value: 'John' })
  ]
});
console.log(andFilter.toString()); // '(&(sn=Doe)(givenName=John))'