morphine

living high on simple DI

Heavily inspired by Angular ui.router $resolve. I wrote this after a stressful day of Shepherd.js and other DI libs making me feel stupid. I am making some micro-services and didn't want to deal with proper DI, I just wanted something like a recursive Promise.all()

Ripped some regex magic out of Angular's $inject code, combined with a rewrite of ui.router's $resolve, and you get some sexy Promise dependency injection thing that looks like it was made with sweet.js.

Example:

var resolve = require("morphine");

resolve({
  now: function(path){
    return path;
  },
  future: function(path, now){
    return path + now;
  }
},{path: "something"})
.then(console.log);

output

{ path: 'something',
  now: 'something',
  future: 'somethingsomething' }

API

resolve(invokables, [knowns]) -> promise

invokeables:

An invokeable is a name (key) and a function with zero or more arguments that map to some or all of the keys in the invokeables object (resursive), or the knowns object. The return values for the invokeables functions can be promises. internally they get converted to promises anyway.

knowns:

an object of primative values (strings, ints).

resolve():

The return value (promise) that resolve gives is an object with the keys from both the invokeables and knowns list, and the resolved values from all of the invokeables (primatives).

More Examples:

resolve({
  now: function(path){
    return "something";
  }
})
.then(console.log);

output

{ path: 'something'}

var fs = require("q-io/fs");
resolve({
  config: function(configPath){
    return fs.read(configPath).then(JSON.parse);
  }
},{configPath: "config.json"})
.then(console.log);

output

{ configPath: 'config.json',
  config: { obj: { field: [Object] }, server: { port: 1111 } } }

what happens when you you make typos

resolve({
  path: function(){
    return "something";
  },
  fail: function(noResolution, path){
    return noResolution + path;
  }
})
.then(null, _.partial(console.log, "failure case"));

output

failure case [Error: can not resolve all dependencies: noResolution]