The test cases don't include the case of more than one only-zeros array. My code works for all the given test cases but fails the case when it's an array of more than one only-zeros e.g. [0, 0, 0].

Understand what the interviewer is asking for by using test cases and questions about the problem. Established a set (2-3) of test cases to verify their own solution later. Established a set (1-2) of ...