Behavior when loaded with node is confusing

If someone tries to require the module from Node (like in a REPL below)

$ node 
> require('fitty')
{ default: undefined }
> require('fitty').default
undefined
> require('fitty').default()
TypeError: require(...).default is not a function

It isn’t clear what went wrong. I’d really recommend throwing an error or at least logging to stderr when this is attempted, at this point in your code:

  // no window, early exit
  if (!w) {
    // throw or log error here please
    return;
  }

It was really confusing to me when, separately, I wasn’t able to get the import working as expected.

Oh, and thanks for writing fitty!

[rikschennink]

@searls happy to merge any pull requests that fix this

[searls]

The same functions to be there, regardless of whether they worked. For example, I’d bail at the last possible moment, and not at require-time. Maybe a user will require jsdom right afterward only to find fitty is {default: undefined} instead of {default: function thisWillBlowUpWithoutADom(){}}.