@atlaskit/global-search/dist/es2019/util/autocomplete.js

A cross-product search component (batteries included)

import memoizeOne from 'memoize-one';
export const getAutocompleteText = memoizeOne((query, autocompleteSuggestions) => {
  if (!autocompleteSuggestions || query.length === 0) {
    return undefined;
  }

  if (autocompleteSuggestions.length === 0) {
    return query;
  }

  const lowerCaseQuery = query.toLowerCase();
  const match = autocompleteSuggestions.find(suggestion => suggestion.toLowerCase().startsWith(lowerCaseQuery));

  if (!match) {
    return query;
  }

  return `${query}${match.slice(query.length)}`;
});