Diagnostics after didChange contain incorrect ranges

Hello,

This issue might be related to the know issue that on-the-fly diagnostics are mostly unimplemented. If that's the case, I apologize for the noise. I wanted to bring it up anyway.

When making changes to a file without saving, the editor will only send textDocument/didChange notifications to the server. As a result of this, some times the server will then send a textDocument/publishDiagnostics. However, some times the diagnostics coming for this request contain incorrect ranges, which cases warning/error markup to be rendered in incorrect places by the editor.

Here is a GIF showing this behaviour on VS Code:

What is happening here is that the textDocument/publishDiagnostics notification contains ranges for the latest saved version of the file, not the one reported by textDocument/didChange. The interesting bit is that the textDocument/publishDiagnostics notification does contain a version field which matches perfectly with the one sent by textDocument/didChange. It's just that the ranges are incorrect.

This was tested with the released version of rust-analyzer from 2021-05-10. Please let me know if you need more information for debugging.

Start by reproducing the issue in VS Code while inspecting textDocument/didChange and textDocument/publishDiagnostics notifications, especially their version and ranges. Done means diagnostics for an unsaved file use ranges from the matching changed version rather than the latest saved version.