message: document return type
diff: @@ -57,7 +57,9 @@ export function diffDeletion(oldStr, newStr) {
  * @param {String} oldValue the previous value
  * @param {String} newValue the new value
  * @param {Number} caretPosition the position of the caret after `newValue` was applied.
  - * @return {object}
  + * @return {object} an object with `at` as the offset where characters were removed and/or added,
  + * `added` with the added string (if any), and
  + * `removed` with the removed string (if any)
  */
  export function diffAtCaret(oldValue, newValue, caretPosition) {
  const diffLen = newValue.length - oldValue.length;
  