Easily import packages (non ember addons) from node_modules (you can import from any folder if you want to)
NOTE: From Ember CLI version 2.15, packages from node_modules folder can be imported directly using app.import in ember-cli-build.js file . Refer here for release notes.
ember install ember-cli-node-modules-to-vendor
// ember-cli-build.js
// ...
var app = new EmberApp(defaults, {
  nodeModulesToVendor: [
    'node_modules/some-package/dist/js'
  ]
});
// then you can easily do
app.import('vendor/a-file-from-the-folder-above.js');
// ...You can supply a tree if you want finer control:
// ember-cli-build.js
var Funnel = require('broccoli-funnel');
var UnwatchedDir = require('broccoli-source').UnwatchedDir;
// ...
var app = new EmberApp(defaults, {
  nodeModulesToVendor: [
    /* UnwatchedDir is optional, but it is rare to need a watcher assigned to a node_modules dependencies */
    new Funnel(new UnwatchedDir('node_modules/some-package/dist/js'), {
      destDir: 'some-package',
      files: ['only-this-file.js']
    })
  ]
});
app.import('vendor/some-package/only-this-file.js');Note: omitting the destDir option will place the file directly into the vendor
folder, so app.import('vendor/only-this-file.js') would be your import instead.
You can conditionally import:
// ember-cli-build.js
// ...
function isDevelopment() {
  return EmberApp.env() !== 'production';
}
// ...
var nodeModulesToVendor = [];
if (isDevelopment()) {
  nodeModulesToVendor.push('node_modules/dev-helper/dist');
}
var app = new EmberApp(defaults, {
  nodeModulesToVendor: nodeModulesToVendor
});
if (isDevelopment()) {
  app.import('vendor/a-file-from-the-folder-above.js');
}
// ...