• sequel to the EF Core post — was trying to learn the ORM, got stuck fighting the editor instead
  • override completions (OnConfiguring, OnModelCreating, etc.) silently break in nvim-cmp + roslyn.nvim
  • keywords complete fine, method scaffolds don’t — the kind of bug that makes you question your entire config
  • spent 90 minutes with Claude debugging this layer by layer — it was wrong five times before it was right, but it was a relentless pair partner
  • the root cause: cmp-nvim-lsp sends completion commands directly to the Roslyn server, bypassing every client-side handler Neovim and roslyn.nvim provide
  • roslyn.nvim already ships the fix (lua/roslyn/lsp/commands.lua) — cmp-nvim-lsp just never calls it
  • the .client. in roslyn.client.completionComplexEdit is the tell — it’s a client-side command, the server literally can’t handle it
  • fix is a monkey-patch on the roslyn client’s request method — intercept before it hits the wire, route to the local handler
  • but cmp already applied its textEdit before the command fires, so the buffer state is wrong for the complexEdit’s ranges
  • undo scoping: <C-G>u break point before cmp.confirm() so silent! undo only reverts cmp’s edit, not the whole insert session
  • then autopairs fires on confirm_done and injects stray () after the scaffold — because of course it does
  • buffer-local flag (vim.b.roslyn_complex_edit) to suppress autopairs during complexEdit completions
  • cursor positioning: Roslyn parks you after the ; but the natural spot is inside the base call’s parens
  • three files touched: roslyn.lua, completion.lua, and your sanity
  • the code works, is labeled as AI-generated spaghetti in the comments, and I’m not sorry
  • this is the kind of DX gap that makes people give up on non-VS-Code .NET development
  • nobody should have to debug LSP protocol routing just to get method completions working
  • the fix is reusable — anyone running roslyn.nvim + nvim-cmp will hit this wall eventually
  • point readers to the repo: EntityFrameworkCore learning project — roslyn.lua and completion.lua are the files, documented inline
  • broader point: Neovim .NET dev is possible and genuinely good once you clear these hurdles — but clearing them is an unreasonable ask without someone else having done it first
  • this post is that someone else