Pull diagnostics are a relatively new feature in the LSP specification where the client requests the server for diagnostics, instead of the server notifying the client. Known servers that use this feature include ruby-lsp and the new Roslyn language server for .NET.

New capabilities:

• textDocument.diagnostic (client)
• diagnosticProvider (server)

New methods:

• textDocument/diagnostic - Computes diagnostics for a single document, and possibly related documents
• workspace/diagnostic - Computes workspace-wide diagnostics which were previously published from server to client
• workspace/diagnostic/refresh - Refreshes workspace-wide diagnostics, used when a project-related change is detected

Related:

joaotavora/eglot#1290
neovim/neovim#22838
neovim/neovim#24128