/^test\d{1,}(.*[^~])?$/
[download]

the hard part is that, based on your description, the pattern should match "test1" and not match "test1~". so a plain [^~] at the end doesn't work, because the requires another character after the 1 digit, which should be optional. so the whole thing is optional.

question: how does /^test\d+/.*/ work? i've seen regexes matches with 3 delims before but never quite got it