@idan-loo/middleware

middleware

Create your own middlewares to divide a large logic into serveral wares.

It is inspired by the middleware system of Koa

Install

# with npm
npm install --save @idan-loo/middleware
# with yarn
yarn add @idan-loo/middleware

Usage

import { executorOf } from '@idan-loo/middleware'

const mw1 = async (ctx, next) => {
  ctx.name = 'mw1'
  await next()
}

const mw2 = async (ctx, next) => {
  ctx.name = 'mw2'
  await next()
}

const mw3 = async (ctx, next) => {
  ctx.name = 'mw3'
  await next()
}

const exec = executorOf({ name: 'test' })
await exec(mw1, mw2, mw3)

Middleware

Each middleware should return a Promise object. You can simply add an async keyword in front of the function declation, or just return next().

import { Next } from '@idan-loo/middleware'

type Context = {
  name: string,
}

const mw1 = async (ctx: Context, next: Next) => {
  ctx.name = 'mw1'
  return next()
}

const mw2 = async (ctx: Context, next: Next) => {
  ctx.name = await anAsyncAction()
  await next()
}

const mw3 = async (ctx: Context, next: Next) => {
  await next()
  ctx.name = 'after next'
}

If you want to go on executing the next middlewares, you should call next() manually.

import { executorOf } from '@idan-loo/middleware'

const mw1 = async (ctx: Context, next: Next) => {
  ctx.name = 'mw1'
  return next()
}

const mw2 = async (ctx: Context) => {
  ctx.name = 'mw2'
}

const mw3 = async (ctx: Context, next: Next) => {
  ctx.name = 'mw3'
  return next()
}

const exec = executorOf({ name: 'test' })
// mw3 won't be executed because mw2 doesn't call the next method
exec(mw1, mw2, mw3)