Sandboxes:
- sandbox 1, sandbox 2.1 and sandbox 3, when one just doesn't cut it
- sandboxjson for unique pagetype testing
- sandboxmessy - the literal sandbox
- SafeEnvironmentTesting - somewhat defunct sandbox, still sometimes used for certain tests
Module:Sandbox/Aidan9382 - module coding
Any linter errors here are likely intentional as part of testing. Do not fix them