How to create a new file or directory to the tree

[websiddu]

Can there be a quick code snippet or guidance on how to create a new file/directory to the tree?

[jaredLunde]

There are a bunch of examples in tests: https://github.com/jaredLunde/exploration/blob/main/src/file-tree.test.ts#L655

Unfortunately I lost access to the web IDE I built this for when I left DigitalOcean last year so I don't have complete examples on hand.

[jaredLunde]

I've been meaning to add more examples to CodeSandbox, I just haven't found the time