Expose mdc-ripple's util.js for ES5

I’m implementing custom MDCRippleFoundation adapter. As you mentioned in document, supportsCssVariables function in util.js would be useful to implement browserSupportsCssVars() => boolean. But, @material/ripple/dist/mdc.ripple does not exposes the utils module. So I cannot use the module without transpiler configured for MDC.

/*
 * In `some_library/src/foo.js`
 * Will be transpiled to ES5 code in `some_library/lib/foo.js`
 */
import {supportsCssVariables} from '@material/ripple/util';

...

If i use transpiler to use that module, users of some_library also have to use same transpiler. But It does not seem to be good constraints.

/* In application that does not use any transpiler  */

// Raises syntax error when importing `@material/ripple/util`
var RippleWrapper = require('some_library/lib/foo.js'); 

[traviskaufman]

@Hardtack fair point. I can see the value in exposing the ripple’s util module via index.js. However, as a general rule we’ll probably only expose util-like modules on a case-by-case basis.

We don’t want to add too much to a public API right off the bat, only to change/remove something thus causing a breaking change.

[codesuki]

I also had that problem.

Anyhow for now you can circumvent it by doing the following:

rippleFoundation = new MDCRippleFoundation(Object.assign(MDCRipple.createAdapter(this), {
// your funcs
}

This will give you a default foundation that already uses supportsCssVariables so you don’t have to implement it yourself.