The original question is whether you add a project to an actor’s resume when it books, films or airs. What about on IMDB? The answer is…that depends on several things, like whether the role or character name is a spoiler, and if production has a reason not to include it. Otherwise, when you film, list it.
The next question was do you ever list a role you didn’t get? Really? A green actor might list a role they tested for, but do you want future employers to know you didn’t book? Find out why that isn’t a good idea.