IDE functionality in unsaved examples

While your basic GUI editor like VS Code can’t do it, the majority of command line editors support providing the path a file will be saved under prior to actually writing out the buffer upon first save.

I realize this could be an issue with the LSP client, so please correct me if so, but in cases where the user creates a buffer associated with an unmaterialized path, could RA use that path instead of showing errors about the buffer not being part of the crate tree?

eg :e examples/foo.rs will currently trip up RA until a :w is issued, but does that need to be the case (assuming the client sends the path along)?

Start by reproducing the :e examples/foo.rs case before and after :w, then trace how the LSP client provides the unsaved path and how rust-analyzer checks whether a buffer belongs to the crate tree. Done means an unsaved buffer with a valid future path no longer triggers the reported crate-tree errors, while the existing save workflow remains correct.