Refactor Command#handlers

lib/command.js

@@ -10,16 +10,6 @@ const defaultVersionAction = instance => console.log(instance.meta.version);
 const lastCommandHost = new WeakMap();
 const lastAddedOption = new WeakMap();
 
-const handlers = ['init', 'applyConfig', 'finishContext', 'action'].reduce((res, name) => {
- res.initial[name] = name === 'action' ? self : noop;
- res.setters[name] = function(fn) {
- this.handlers[name] = fn.bind(null);
-
- return this;
- };
- return res;
-}, { initial: {}, setters: {} });
-
 export default class Command {
  constructor(usage = '') {
  const [name, params] = usage.trim().split(/(\s+.*)$/);
@@ -34,12 +24,34 @@ export default class Command {
  help: null
  };
 
- this.handlers = { ...handlers.initial };
- Object.assign(this, handlers.setters);
+ this.handlers = {
+ init: noop,
+ applyConfig: noop,
+ finishContext: noop,
+ action: self
+ };
 
  this.help();
  }
 
+ // handlers
+ init(fn) {
+ this.handlers.init = fn.bind(null);
+ return this;
+ }
+ applyConfig(fn) {
+ this.handlers.applyConfig = fn.bind(null);
+ return this;
+ }
+ finishContext(fn) {
+ this.handlers.finishContext = fn.bind(null);
+ return this;
+ }
+ action(fn) {
+ this.handlers.action = fn.bind(null);
+ return this;
+ }
+
  // definition chaining
  extend(fn, ...args) {
  fn(this, ...args);