I haven't done this with WAB, but for C# projects I use Visual Studio Online source control and it works well. I can work on code on my main desktop machine, check it into source control and then get the latest revisions on my laptop. Laptop revisions can be checked in the same way. Version control systems have the added benefit of being able to revert to an earlier version of a file. Using GitHub or any other source control system would be a similar experience.
The only issue in my situation is the laptop does not have some of the drive mappings that the desktop does so I sometimes need to point code to test data on a different drive. You could get around this by putting test data into source control as well but some of my projects generate a lot of data so it is easier to change the drive path.
When copying folders, you generally end up with multiple copies of the source all over the place making it difficult to track changes and versions.