How many unit tests should I write per function/method?

Question

Do you write one test per function/method, with multiple checks in the test, or a test for each check?

Answer 1

One test per check and super descriptive names, per instance:

@Test
public void userCannotVoteDownWhenScoreIsLessThanOneHundred() {
 ...
}

Both only one assertion and using good names gives me a better report when a test fails. They scream to me: "You broke THAT rule!".