reka-ui/src/Checkbox/utils.ts

Vue port for Radix UI Primitives.

export type CheckedState = boolean | 'indeterminate'

export function isIndeterminate(checked?: CheckedState): checked is 'indeterminate' {
  return checked === 'indeterminate'
}

export function getState(checked: CheckedState) {
  return isIndeterminate(checked) ? 'indeterminate' : checked ? 'checked' : 'unchecked'
}