plugins/treesitter: add workaround for performance.combinePlugins

plugins/languages/treesitter/treesitter.nix

@@ -328,5 +328,10 @@ helpers.neovim-plugin.mkNeovimPlugin config {
       foldmethod = mkDefault "expr";
       foldexpr = mkDefault "nvim_treesitter#foldexpr()";
     };
+
+    # Since https://github.com/NixOS/nixpkgs/pull/321550 upstream queries are added
+    # to grammar plugins. Exclude nvim-treesitter itself from combining to avoid
+    # collisions with grammar's queries
+    performance.combinePlugins.standalonePlugins = [ cfg.package ];
   };
 }

tests/test-sources/plugins/languages/treesitter/combine-plugins.nix

@@ -0,0 +1,37 @@
+{ pkgs, ... }:
+{
+  combine-plugins = {
+    performance.combinePlugins.enable = true;
+
+    plugins.treesitter = {
+      enable = true;
+
+      # Exclude nixvim injections for test to pass
+      nixvimInjections = false;
+    };
+
+    extraConfigLuaPost = ''
+      -- Ensure that queries from nvim-treesitter are first in rtp
+      local queries_path = "${pkgs.vimPlugins.nvim-treesitter}/queries"
+      for name, type in vim.fs.dir(queries_path, {depth = 10}) do
+        if type == "file" then
+          -- Resolve all symlinks and compare nvim-treesitter's path with
+          -- whatever we've got from runtime
+          local nvim_treesitter_path = assert(vim.uv.fs_realpath(vim.fs.joinpath(queries_path, name)))
+          local rtp_path = assert(
+            vim.uv.fs_realpath(vim.api.nvim_get_runtime_file("queries/" .. name, false)[1]),
+            name .. " not found in runtime"
+          )
+          assert(
+            nvim_treesitter_path == rtp_path,
+            string.format(
+              "%s from rtp (%s) is not the same as from nvim-treesitter (%s)",
+              name,
+              rtp_path, nvim_treesitter_path
+            )
+          )
+        end
+      end
+    '';
+  };
+}