Disable CodeSandbox Auto-Formatting
CodeSandbox autoformats your code on save by default, which I find very valuable. Sometimes, when debugging an issue or experimenting with a code style, I don't actually want autoformatting to occur.
This can be disabled under 'Preferences' -> 'Settings' -> 'User Settings' -> 'Format On Save'. Make sure to turn it back on when you're done experimenting.