为什么回调附加到一个事件被调用两次？

Question

我正在梳理this 教程，我很好奇为什么回调被多次调用——在这种情况下是两次。这是我的代码：

'use strict';

var chai = require('chai'),
    expect = chai.expect,
    sinon = require('sinon'),
    sinonChai = require('sinon-chai');

var Backbone = require('backbone'),
    _ = require('lodash/dist/lodash.underscore');

chai.use(sinonChai);

describe('Backbone.Events', function() {
  var myObj;

  beforeEach(function() {
    myObj = {};
    _.extend(myObj, Backbone.Events);
  });

  it('allows us to bind and trigger custom named events on an object', function() {
    var callback = sinon.spy();

    myObj.bind('custom event', callback);
    myObj.trigger('custom event');

    expect(callback).to.have.been.called;      // => passes
    expect(callback).to.have.been.calledOnce;  // => fails??
    expect(callback).to.have.been.calledTwice; // => passes, why?
  });
});

有什么见解吗？

Answer 1

你正在绑定并触发两个事件custom eventcustom和event

尝试将其更改为custom_event