INVALID_SHIM.md

Invalid Shim Warning(s)

What are shims?

The shim feature of RequireJS is a way to declare the external dependencies for a 3rd party library that is not authored as an AMD module.

As an example, consider you have the library jquery-foo.js, which has the following code:

(function($) {
    // Implicit dependency on underscore being available globally
    $.fn.trim = _.trim;
})(jQuery);

For this code to work correctly, the underscore module has to:

1. Fully complete its loading/execution before jquery-foo.js
2. Expose its export (_) on the global object (window or globalThis)

To address this as an application developer, without modifying jquery-foo.js, you need a way to express that it is dependent on underscore. This is exactly what shim config enables.

An example shim config for jquery-foo.js would be:

{
  "shim": {
    'jquery-foo': {
      deps: ['underscore']
    }
  }
}

Why am I seeing warnings?

You are seeing warnings because baler is able to detect some invalid shim configurations, and encourages you to fix them. Although these can work when loading the application without bundling, it is not possible for baler to ensure your application will work when invalid shims are detected.

An example warning from baler:

One or more invalid shim configurations were found while bundling Magento/luma. See https://github.com/DrewML/baler/blob/master/docs/INVALID_SHIM.md
   - mage/common
   - moment
   - jquery/jquery-storageapi

These shim configuration are invalid for the following reasons

mage/common

mage/common has a shim config for jQuery, but mage/common is already an AMD module. Because mage/common has a direct dependency on jQuery, this shim does nothing

moment

moment has a shim config specifying its exported member is moment. However, moment is already an AMD module, so this shim does nothing

jquery/jquery-storageapi

jquery/jquery-storageapi has a shim configuration for jquery.cookie. However, jquery/jquery-storageapi is already an AMD module with its own list of dependencies. Because of this, jquery.cookie does not get loaded before jquery/jquery-storageapi, which breaks Magento 2 stores.