nvim: update flake to Neovim 0.12.4 and add a test suite

.github/workflows/test-install-scripts.yml

@@ -34,7 +34,6 @@ jobs:
           filters: |
             nvim:
               - 'install/nvim/**'
-              - '.github/scripts/verify-nvim.lua'
               - '.github/workflows/test-install-scripts.yml'
             kitty:
               - 'install/kitty.sh'
@@ -82,17 +81,9 @@ jobs:
           which nvim
           nvim --version | head -5
 
-      - name: Test nvim startup
+      - name: Run nvim test suite
         shell: bash
-        run: |
-          export PATH="$HOME/.nix-profile/bin:$PATH"
-          nvim --headless "+qa"
-
-      - name: Verify plugins and bundled tools load
-        shell: bash
-        run: |
-          export PATH="$HOME/.nix-profile/bin:$PATH"
-          nvim --headless -c "luafile .github/scripts/verify-nvim.lua" +qa
+        run: nix run ./install/nvim#test
 
   test-kitty-install:
     needs: changes

install/nvim/config/lua/plugins/lsp.lua

@@ -101,6 +101,16 @@ local servers = {
         telemetry = {
           enable = false,
         },
+        runtime = {
+          version = "LuaJIT",
+        },
+        workspace = {
+          checkThirdParty = false,
+          library = {
+            vim.env.VIMRUNTIME,
+            vim.api.nvim_get_runtime_file("lua/lspconfig", false)[1],
+          },
+        },
       },
     },
   },

install/nvim/flake.nix

@@ -51,7 +51,7 @@
           lua-language-server
           basedpyright
           clang-tools
-          nodePackages.bash-language-server
+          bash-language-server
           stylua
           python3Packages.yapf
           fzf
@@ -82,9 +82,43 @@
           wrapperArgs = neovimConfig.wrapperArgs
             ++ [ "--prefix" "PATH" ":" (pkgs.lib.makeBinPath extraBinaries) ];
         });
+
+        nvimTest = pkgs.writeShellApplication {
+          name = "nvim-test";
+          runtimeInputs = [ nvim pkgs.coreutils ];
+          text = ''
+            tmp="$(mktemp -d)"
+            trap 'rm -rf "$tmp"' EXIT
+            export XDG_DATA_HOME="$tmp/data"
+            export XDG_STATE_HOME="$tmp/state"
+            export XDG_CACHE_HOME="$tmp/cache"
+            mkdir -p "$XDG_DATA_HOME" "$XDG_STATE_HOME" "$XDG_CACHE_HOME"
+
+            # Mirror the live-or-baked pattern the config itself uses, so local
+            # edits are testable without committing them for nix to see.
+            tests="$HOME/dotfiles/install/nvim/tests"
+            if [ ! -d "$tests" ]; then
+              tests="${./tests}"
+            fi
+
+            status=0
+            nvim --headless \
+              --cmd "lua vim.g.nvim_tests_dir = '$tests'" \
+              -c "luafile $tests/run.lua" || status=$?
+
+            rm -rf "$tmp"
+            trap - EXIT
+            exit "$status"
+          '';
+        };
       in {
         packages.nvim = nvim;
+        packages.test = nvimTest;
         packages.default = nvim;
+        apps.test = {
+          type = "app";
+          program = "${nvimTest}/bin/nvim-test";
+        };
       }
     );
 }

install/nvim/tests/helpers.lua

@@ -0,0 +1,61 @@
+-- Shared bootstrap for the nvim config test suite.
+--
+-- The nix wrapper starts Neovim with the config split across two mechanisms:
+--   VIMINIT="lua dofile('/nix/store/<hash>-init.lua')"   (environment)
+--   --cmd "set packpath^=/nix/store/<hash>-vim-pack-dir" (argv)
+--   --cmd "set rtp^=<same>"                              (argv)
+--
+-- mini.test spawns child processes with a hardcoded `--clean`, which discards
+-- both. So we recover them from the running parent and pass them to the child
+-- explicitly. Without this a child has no mapleader and no plugins.
+
+local M = {}
+
+--- Reconstruct the argv a child needs in order to load the real config.
+---@return string[]
+function M.config_args()
+  local viminit = vim.env.VIMINIT
+  assert(viminit, "VIMINIT unset - tests must run under the nix-wrapped nvim")
+
+  local init = viminit:match("dofile%(.([^'\"]+).%)")
+  assert(init, "could not extract init path from VIMINIT: " .. viminit)
+
+  local pack
+  for _, p in ipairs(vim.opt.packpath:get()) do
+    if p:match("vim%-pack%-dir") then
+      pack = p
+      break
+    end
+  end
+  assert(pack, "no vim-pack-dir on packpath")
+
+  return {
+    "--cmd",
+    "set packpath^=" .. pack,
+    "--cmd",
+    "set rtp^=" .. pack,
+    "-u",
+    init,
+  }
+end
+
+--- A child Neovim preloaded with the args needed to reach the real config.
+function M.new_child()
+  local child = MiniTest.new_child_neovim()
+  child.args = M.config_args()
+  return child
+end
+
+--- A test set that gives every case a freshly restarted child.
+function M.new_set(child)
+  return MiniTest.new_set {
+    hooks = {
+      pre_case = function()
+        child.restart(child.args)
+      end,
+      post_once = child.stop,
+    },
+  }
+end
+
+return M

install/nvim/tests/run.lua

@@ -0,0 +1,39 @@
+-- Entry point. `vim.g.nvim_tests_dir` is set by the flake app.
+local dir = vim.g.nvim_tests_dir
+assert(dir, "vim.g.nvim_tests_dir not set - run via `nix run ./install/nvim#test`")
+
+package.path = dir .. "/?.lua;" .. package.path
+
+require("mini.test").setup {
+  collect = {
+    find_files = function()
+      return vim.fn.globpath(dir, "test_*.lua", true, true)
+    end,
+  },
+}
+
+-- MiniTest.collect() re-raises (via `error`) any failure while sourcing a
+-- test file (e.g. a broken top-level `assert` in a shared helper), and
+-- MiniTest.run() does not guard that call. Left unguarded, nvim prints the
+-- error (E5113) and then just sits there in headless mode instead of exiting
+-- nonzero, turning a bootstrap bug into a CI hang. Guard it ourselves.
+local ok, err = pcall(MiniTest.run)
+
+if not ok then
+  vim.api.nvim_err_writeln("nvim-test: bootstrap error: " .. tostring(err))
+  vim.cmd "cquit 1"
+end
+
+-- MiniTest.run() calls `cquit 0`/`cquit 1` itself (via the stdout reporter's
+-- `finish` hook) as soon as at least one case was collected, for both the
+-- passing and failing case, and that never returns control here. So reaching
+-- this point means zero cases were collected - e.g. the glob or tests dir
+-- resolved wrong - which mini.test would otherwise treat as a vacuous pass.
+-- Refuse that instead of exiting 0 having tested nothing.
+local all_cases = MiniTest.current.all_cases
+if all_cases == nil or #all_cases == 0 then
+  vim.api.nvim_err_writeln "nvim-test: collected 0 test cases - refusing to report success"
+  vim.cmd "cquit 1"
+end
+
+vim.cmd "qall!"