Middleware

One of the smallest middleware implementations out there.

No dependencies to other libraries. Works in node and the browser. Handles asynchronous and synchronous functions.

Middleware pattern

Benefits of using the middleware pattern:

• decouple the sender from it receiver
• allows single responsability principle
• allows open/closed principle

Usage

import middleware from 'middleware';

/*
 * Declare middleware functions
 */
async function authenticateMiddleware(request, next){
  const isAuthenticated = await userIsAuthenticated(request)
  if(isAuthenticated) {
    next(firstMiddlewareValue);
  } else {
    throw 'Not authorised user';
  }
}

async function authorizeMiddleware(request, next){
  const isAuthorized = await authorized(request)
  if(isAuthorized) {
    next(request);
  } else {
    throw 'Not authorised user';
  }
}

/*
 * Create chain of middlewares to execute
 */
const middlewareRunner = middleware([
  authenticatedMiddleware,
  authorizedMiddleware,
  function(data, error){
    // Code
  }
]);

middlewareRunner(request);