curse-filter

curse-filter is a fully-equipped Node.js library that simplifies profanity filtering in 15+ different languages.

Installation

npm install curse-filter

Loading the module

ESM / Typescript

This module is first thought for Typescript/ESM, so this is the recommended way to load it.

import { filter } from 'curse-filter';

Usage

supportedLangs

import { supportedLangs } from 'curse-filter';

console.log(supportedLangs); // This will log an array of supported languages

filter()

The filter() function will return a string with all curse words replaced with asterisks ("***").

import { filter } from 'curse-filter';

filter('fuck you'); // '*** you'
filter('fuck you', 'en'); // '*** you'
filter('fuck you, coglione', ['en', 'it']); // '*** you, ***'
filter('fuck you, coglione', ['en', 'it'], 'customPlaceholder'); // 'customPlaceholder you, customPlaceholder'

Alternately, if you want to reduce filtering time, you can pass as second parameter a string of an array of string (all supported languages).

import { filter } from 'curse-filter';

const str = '<...>';

filter(str); // automatically selects all languages
filter(str, 'en');
filter(str, ['en', 'es', 'fr', 'it']);

detect()

The detect() function will return a boolean representing whether or not curse words are in a string.

import { detect } from 'curse-filter';

// you can select the languages to detect in the second argument, like in the `filter()` function

console.log(detect('Fuck you')); // true
console.log(detect('Fuck you', 'en')); // true
console.log(detect('Fuck you', ['en', 'fr'])); // true
console.log(detect('Fuckyou', 'en')); // false, view next paragraph.
console.log(detect('I love you')); // false

For more rigid use cases, you can use rigidMode option to also detect curse words that are part of bigger words (For example, for hiding them!).

import { detect } from 'curse-filter';

console.log(detect('Fuckyou', 'en')); // false, the word "Fuck" is inside of a bigger word: "Fuckyou"
console.log(detect('Fuckyou', 'en', { rigidMode: true })); // true, the word "Fuck" is detected even if part of a bigger word

Promise versions

You can access promise versions of filter and detect functions from curse-filter/promises.

import { filter, detect } from 'curse-filter/promises';

const main = async () => {
    const filtered = await filter('Fuck you');
    const detected = await detect('Fuck you');

    console.log(filtered, detected); // '*** you', true
};

main();

Adding custom keywords to search for

curse-filter offers a nice and familiar way to add strings or arrays of strings to the words to search for with the CustomKeywords Set-like object.

import { filter, CustomKeywords } from 'curse-filter';

CustomKeywords.add('Hello'); // Hello

// Custom method of CustomKeywords object
CustomKeywords.addKeywords('Hey', 'Hi', ['Bonjour', 'Ciao']); // Hello, Hey, Hi, Bonjour, Ciao

// The filter and detect functions automatically look for custom keywords added to the object
const result = filter('Hey John!');
console.log(result); // '*** John!'

Express.js middlewares

curse-filter comes with built-in express.js middlewares.

detectMiddleware middleware

The detectMiddleware middleware analizes the whole req.body object for curses.

import express, { Request, Response } from 'express';
import { detectMiddleware } from 'curse-filter';
import { registerUserToDB } from './db';

const app = express();

app.use(express.json());

app.post('/register', detectMiddleware, async (req: Request, res: Response) => {
    /* If the request body contains curse words, the middleware will automatically 
    send a 422 response with a message containing the detected curse words.
    If no curse words are detected, the middleware will call the next() function. */

    await registerUserToDB(req.body);

    res.status(200).json({ message: 'User registered!' });
});

You can configure the middleware with the following options:

// Class for configuring the middleware
import { MiddlewaresConfig } from 'curse-filter';

// Default values:

MiddlewareConfig.onError = null; // Called when a curse word is detected, before sending the response

MiddlewareConfig.detectOptions = {}; // Options for the detect function

MiddlewareConfig.errorMessage = 'Not allowed content detected.'; // Message sent in the response

MiddlewareConfig.statusCode = 422; // Status code sent in the response

Typescript

SupportedLang type

import { SupportedLang } from 'curse-filter';

const lang: SupportedLang = 'en';

Custom Set interfaces

import { KeywordsSet, KeywordsSetConstructor } from 'curse-filter';

/*
 * KeywordsSet is a Set<string> with a custom addKeywords method
 * KeywordsSetConstructor is a SetConstructor with a custom addKeywords method
 */

License

MIT