Radio button background not grey on de-select

[robmckinnon]

Radio button backgrounds are no longer being re-greyed on de-select in the radio button section of the GOV.UK elements guide:

Checkboxes are not effected by this issue. They are still being re-greyed on de-select.

The changes to selection-buttons.js in this govuk_elements commit may have introduced the radio button issue. This issue has also been reported at the govuk_elements repo here: alphagov/govuk_elements#54

[tombye]

From a quick debug, looks like this is because they're not wrapped in a form.

When the selection in a radio group shifts from one to the other in the group, the JS in selection-buttons.js searches for the group within the parent form. If there is no parent form, it won't be able to find the group.