A middleware chain for plugins based only on async/await and dependency injections

• Features
• Motivations
• Examples
• Installation
• How does it work?
• API Documentation
• License

• extremely simple: the API exposes only two function : .use() and .run() !
• chainability: isn't that obvious, it's a chain, so all calls can be chained onto the previous one !
• simple semantic: to succeed, all links of the chain must give back a result, a single exception and the chain is broken !
• dependency injection: give all of your plugins all the goodies they want (free logger, free context, free tools...) so that they will require less dependencies !
• recursivity: a chain can be given to another chain and become a single link in a new process
• tracability: the api enforces giving chains and plugins a name so that every single step of execution can be very traceable !
• no dependency: yep

There is a great deal of chain middlewares around there. So why a new one ? The answer to this question is quite simple : to go forward !, and to get rid of all the outdated libraries that were based on the callback(err, ..) paradigm (otherwise known as callback-hell) We think that this programmatic paradigm has served node.JS well (pretty well in fact as it radically redefined the asynchronous way of thinking for programmers), but now that a powerful replacement is available natively in the form of the async/await statements, it's time to leave that past in the dust...

So, simply told : the chain middleware does not support the callback(err, what) paradigm.

That's the other strongest motivation for this library : a lot of these other libraries totally forgot another key point of interest of using a middleware framework : the freebies !

I mean,

You'll need Node.js 8 or higher then, type in the console and in your project's directory :

npm install --save chain

or

yarn add chain

Now, let's write a simple program that (...)

const chain = require('chain')

// let's write the most simple chain
chain('hello', {ensurePluginName: false}).use(str => str + ' World').use(console.log).run('Hello')