The test case should be revised to test for edge case solutions as I saw that somebody's solution has passed but it didn't found solutions that contained digit 8 or 9

The description doesn't need to be updated because:
Ad. 1 Description says you have to "break a code of 3 digits" not numbers, and digits are integers;
Ad. 2 Digits are numbers but numbers aren't necessarily a digits, so they have their min/max value (look at the definition of digit)

This solution isn't a best practice because it can't find digit 9. E.g. for edge case of solution being [9, 9, 9], or any other solution where one of digits is 9, your tryCode function will not find a solution.