@art-of-coding/compose

Compose

Simple utility to compose multiple async/await middleware functions into a single middleware function.

Also see @art-of-coding/lime.

Install

npm i @art-of-coding/lime-compose

API

compose()

compose<C = Context> (...middlewares: MiddlewareFunction<C>[]) => MiddlewareFunction<C>

Composes the middlewares into a single middleware function.

TypeScript users can provide a context definition (C) which allows type checking within the middlewares. For more information about type checking see index.ts.

Example

import compose, { Context } from '@art-of-coding/lime-compose'

// Optional context definition
// May extend `Context`, but this is not necessary
interface MyContext extends Context {
  age?: number
}

const composed = compose<MyContext>(
  async (ctx, next) => {
    // 1st middleware
    ctx.age = 18
    await next()
  },
  async (ctx, next) => {
    // 2nd middleware
    await next()
  },
  async ctx => {
    // 3rd middleware
  }
)

const ctx = {}
composed(ctx).then(() => {
  // middleware completed
}).catch(err => {
  // middleware error
})

License

Copyright 2019 Michiel van der Velde.

This software is licensed under the MIT License.