Sprite image and style does not generated

[hilo2120]

Here is my code:

var nsg = require('node-sprite-generator');
  nsg({
      src: ['images/1.jpg',
        'images/2.jpg',
        'images/3.jpg'
      ],
      spritePath: 'sprite.png',
      stylesheetPath: 'sprite.css',
      stylesheet: 'css'
  }, function (err) {
      console.log('Sprite generated!');
  });

When i run it using node sprite.js It says "Sprite generated!" but nothing happens, there is no sprite.png and no sprite.css!
I'm using vscode internal terminal.

[oscarqht]

I encounter similiar issue, printing the error object of the callback function shows:

TypeError: expecting a function but got [object Null]
    at apiRejection (/.../node_modules/bluebird/js/release/promise.js:10:27)
    at map (/.../node_modules/bluebird/js/release/map.js:136:16)
    at Promise.map (/.../node_modules/bluebird/js/release/map.js:160:12)
    at generateSprite (/.../node_modules/node-sprite-generator/lib/spriteGenerator.js:74:10)
    at generateSpriteNode (/.../node_modules/node-sprite-generator/lib/index.js:15:12)
    at Object.<anonymous> (/.../scripts/spritesheet.js:17:1)
    at Module._compile (internal/modules/cjs/loader.js:701:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:712:10)
    at Module.load (internal/modules/cjs/loader.js:600:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:539:12)
    at Function.Module._load (internal/modules/cjs/loader.js:531:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:754:12)
    at startup (internal/bootstrap/node.js:283:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:622:3)