Invariants written once, run two ways

Neovim freezes and the configuration is fine. The fault is outside the repository.

• mason has three C# language servers installed: omnisharp, omnisharp-mono and csharp-language-server. All three attach to a .cs buffer, so the solution loads three times and the UI thread stays blocked until the first highlight. The configuration asks for one. The other two are simply present.
• lsp.log is several megabytes. Some server is flooding WARN, and every line of it is written synchronously while you edit.
• blink.cmp loaded before InsertEnter. Requiring it costs about a second on the machine, and that second is now on every file open.

None of these show up in a linter. What is in the repository is right, and what is around it has drifted.

The assertions live in one module#

nvim/src/lua/my/checks/init.lua holds all of them. Each function returns a list of { ok, msg } and touches neither the display nor the exit code.

M.lsp_log_size = function()
  local max_bytes = 5 * 1024 * 1024
  local path = vim.lsp.get_log_path()
  local stat = vim.uv.fs_stat(path)
  local size = stat and stat.size or 0
  return { result(size < max_bytes,
    ("lsp.log is %.1f MB (%s)"):format(size / 1024 / 1024, path)) }
end

The same checks are wanted in two places: interactively, and in CI. Written twice, one copy gets fixed and the other quietly stops agreeing.

:checkhealth my reports what is true now#

lua/my/health.lua pushes each result into vim.health.ok or .error.

The LSP attachment check is the exception, because it needs an open buffer to say anything. So it walks the loaded buffers and looks only at the filetypes with a declared expectation, and says so when none qualify.

M.expected_lsp_clients = { cs = { "omnisharp" }, lua = { "lua_ls" } }
M.lsp_client_noise = { copilot = true, ["null-ls"] = true, ["GitHub Copilot"] = true }

The noise list is there because clients that belong to no language attach to the same buffer. Without it, having copilot running is enough to fail the comparison.

CI has to create the state first#

Headless, there are no open buffers. nvim/tests/cs_single_lsp.lua opens a fixture .cs file and waits up to 120 seconds for omnisharp to attach.

Then it waits five seconds more.

vim.wait(5000) -- let any unexpected second server show itself

“No second server attached” cannot be observed at an instant. The second one may simply not have arrived. An absence has to be waited for.

The probe skips when omnisharp is not installed. The workflow runsMasonInstall omnisharp explicitly, so the skip cannot quietly swallow the check on CI.

Exit codes, and getting them to run#

Each probe ends in cq! or qa!. cq! is the non-zero one.

nvim/tests/run.sh walks nvim/tests/*.lua. Two things catch it out:

• Check for GNU timeout before using it. Windows ships a different program under the same name in System32. The probe is whethertimeout 1 true succeeds.
• Hand Neovim a native path. Neovim on Windows cannot open an MSYS-style /d/... path, so each file goes through cygpath -m first.

The workflow runs them on ubuntu and windows, and only when nvim/** changes.