Likewise, please could you add two test cases: - for str = "" - and for when there's no whitespace after the specified index

Could you add a test case for the empty array please?

Please add a comment to describe: - What this function does - What are the parameters - What is the output

Could you refactor this into a function to make it clearer what it does?

As this is almost the same code as makeTitleSearchQuery, could you refactor both in a single `makeSearchQuery(query, field)` where field can be either "title" or "body"?