• No mention of what to do if there are 2 sharp numbers
• No random tests
• Finding the most frequent number has obviously been done to death. There are many duplicates

more details could have been provided
if there are more than 1 "sharp numbers", return the first or throw an exception

In test cases there are two tests with the same name.

bad test case

wrong example testcase... nothing new

test 2 ....

The test case Test2() appears twice in C#. Other than that typo it works fine.

C# Unit Tet 2 is already defined.

I thought that in case two numbers have the same number of ocurrences, the first of them in the original array should be picked, no?

Although yeah, it is not obvious from the proposition.

Super minor: There are 2 Test2s. The 3rd test should be Test3.

I the last practice tests, there were as many negative 1's as positive. My program first detected the negative and so gave a wrong answer. If the kata supports negative numbers I think it would be really cool! ;)

Issues with TestCase naming.

Change the second "TestCase2" to "TestCase3"

Or consider a different naming convention.

There are 2 tests with the same name, which causes a compiler error.