DIC.js

//
// Reference: https://medium.com/better-programming/dependency-injection-containers-in-javascript-5fd2c2b4be30
//

import parseFunction from 'parse-function'

const app = parseFunction({
  ecmaVersion: 2017,
})

class DIC {
  constructor() {
    this.dependencies = {}
    this.factories = {}
  }
  
  register(name, dependency) {
    this.dependencies[name] = dependency
  }
  
  factory(name, factory) {
    this.factories[name] = factory
  }
  
  get(name) {
    if (!this.dependencies[name]) {
      const factory = this.factories[name]
      if (factory) {
        this.dependencies[name] = this.inject(factory)
      } else {
        throw new Error('No module found for: ' + name)
      }
    }
    return this.dependencies[name]
  }
  
  inject(factory) {
    const fnArgs = app.parse(factory).args.map((arg) => this.get(arg))
    return new factory(...fnArgs)
  }
}