Enter search text, then click a down arrow; it sets the value of the input:

https://github.com/corejavascript/typeahead.js/blob/master/src/typeahead/typeahead.js#L416

    // cursor moved to different selectable
    if (data) {
      this.input.setInputValue(data.val);
    }

but if the dataset contains objects, this will set the input to [object Object]:

Arrows should only navigate through suggestions; clicking an arrow should not redo the search for just the highlighted suggestion. This change skips setting the input value if data is not a string.