Description

If a match clause only has 2 cases, and the last case is _, then the whole thing can be converted into a simple if-then-else block, which is more readable.

Test1:

match foo with
| bar -> ()
| _ -> ()

Should throw warnings.

Test2:

match foo with
| bar -> ()
| baz -> ()
| _ -> ()

Should not throw warnings (because it has 3 cases, not 2).

Test3:

match foo with
| bar -> ()
| baz -> ()

Should not throw warnings (because its last case is not _).

Test4:

match foo with
| Bar baz -> ()
| _ -> ()

Should not throw warnings (because its first case is not a single element, so the casting is useful).