Middlewarefy makes it easy to make your code more extensible by allowing adding middlewares to any function.

This library works great with TypeScript projects. Everything is typed so that you get autocompletion and type checking. Make sure you are using at least TypeScript 3.1.6!

QuickStart

Installation

npm install --save middlewarefy

Usage

TypeScript

import { middlewarefy } from 'middlewarefy'

const fn = middlewarefy((n: string): string => {
    return n
})

fn.register((next: (n: string) => string, n: string): string => {
    return next('n='+n)
})

const result = fn('5')
// result is 'n=5'

JavaScript

const { middlewarefy } = require('middlewarefy')

const fn = middlewarefy((n) => {
    return n
})

fn.register((next, n) => {
    return next('n='+n)
})

const result = fn('5')
// result is 'n=5'

On a class

import { middlewarefyObj } from 'middlewarefy'

class Test {
    val(n: string): string { return n }
    fn(n: string): string {
        return this.val(n)
    }
}

// Prototype of the function that will be middlewarefied to keep type safety
type Fn = (n: string) => string

const middleware = function(next: Fn, n: string): string {
    return next('n='+n)
}

const middlewarefied = middlewarefyObj<Fn>(Test, 'fn')
middlewarefied.register(middleware)

const test = new Test()
const result = test.fn('5')
// result is 'n=5'

API

middlewarefy(fn)

Wraps the given function in a Middlewarefied object.

import { middlewarefy } from 'middlewarefy'

const fn = middlewarefy((n: string): string => {
    return n
})

middlewarefyObj(target, name)

Finds the function named {name} on the given object. Wraps it and returns a Middlewarefied object. If the function is not found, an error is thrown.

import { middlewarefyObj } from 'middlewarefy'

class Test {
    fn(n: string): string {
        return n
    }
}

// Prototype of the function that will be middlewarefied to keep type safety
type Fn = (n: string) => string

const fn = middlewarefyObj<Fn>(Test, 'fn')

Middlewarefied.register(middleware)

Registers a middleware. A middleware can only be registered once. Any call with an existing middleware will be ignored.

Middlewarefied.unregister(middleware)

Unregisters a middleware. If the middleware was not registered, nothing happens.

Middlewarefied.unregisterAll()

Unregisters all middlewares.

Development

Building

This project needs to be built because it uses TypeScript. Use the following command to build this project:

npm run build

Testing

This project uses mocha and chai for its unit tests. Use the following command to run all the tests:

npm run test

License

This project is licensed under the terms of the MIT license.