modules/performance/combine-plugins: propagate lua dependencies

Plugins from luarocks (e.g. telescope-nvim) have dependencies specified
in propagatedBuildInputs. These dependencies are not added as plugins in
Nvim runtime. They are added to LUA_PATH env var for wrapped neovim.
This commit collects all propagatedBuildInputs from input plugin list
and puts them in the combined plugin.
Note that such dependencies are never combined, because they are not
plugins.

modules/top-level/plugins/mk-plugin-pack.nix

@@ -28,24 +28,38 @@ let
       (builtins.concatMap (f: f ps))
     ];
 
+  # propagatedBuildInputs contain lua dependencies
+  propagatedBuildInputs = lib.pipe pluginsToCombine [
+    (builtins.catAttrs "plugin")
+    (builtins.catAttrs "propagatedBuildInputs")
+    builtins.concatLists
+    lib.unique
+  ];
+
   # Combined plugin
-  combinedPlugin = pkgs.vimUtils.toVimPlugin (
-    pkgs.buildEnv {
+  combinedPlugin =
+    lib.pipe
+      {
         name = "plugin-pack";
         paths = overriddenPlugins;
         inherit pathsToLink;
 
-      # Remove empty directories and activate vimGenDocHook
-      # TODO: figure out why we are running the `preFixup` hook in `postBuild`
+        # buildEnv uses runCommand under the hood. runCommand doesn't run any build phases.
+        # To run custom commands buildEnv takes postBuild argument.
+        # fixupPhase is used for propagating build inputs and to trigger vimGenDocHook
         postBuild = ''
           find $out -type d -empty -delete
-        runHook preFixup
+          fixupPhase
         '';
         passthru = {
           inherit python3Dependencies;
         };
       }
-  );
+      [
+        pkgs.buildEnv
+        pkgs.vimUtils.toVimPlugin
+        (drv: drv.overrideAttrs { inherit propagatedBuildInputs; })
+      ];
 
   # Combined plugin configs
   combinedConfig = lib.pipe pluginsToCombine [

tests/test-sources/modules/performance/combine-plugins.nix

@@ -69,6 +69,17 @@ let
   pluginWithPyDeps3 = mkPlugin "plugin-with-py-deps-3" {
     passthru.python3Dependencies = ps: [ ps.requests ];
   };
+  # Plugins with Lua dependencies
+  ensureDep =
+    drv: dep:
+    drv.overrideAttrs (prev: {
+      propagatedBuildInputs = lib.unique (
+        prev.propagatedBuildInputs or [ ] ++ [ prev.passthru.lua.pkgs.${dep} ]
+      );
+    });
+  pluginWithLuaDeps1 = ensureDep pkgs.vimPlugins.telescope-nvim "plenary-nvim";
+  pluginWithLuaDeps2 = ensureDep pkgs.vimPlugins.nvim-cmp "plenary-nvim";
+  pluginWithLuaDeps3 = ensureDep pkgs.vimPlugins.gitsigns-nvim "nui-nvim";
 in
 {
   # Test basic functionality
@@ -222,6 +233,35 @@ in
       ];
     };
 
+  # Test that plugin lua dependencies are handled
+  lua-dependencies =
+    { config, ... }:
+    {
+      performance.combinePlugins.enable = true;
+      extraPlugins = [
+        simplePlugin1
+        # Duplicated plenary-nvim dependency
+        pluginWithLuaDeps1
+        pluginWithLuaDeps2
+        # nui-nvim dependency
+        pluginWithLuaDeps3
+      ];
+      extraConfigLuaPost = ''
+        -- All packages and its dependencies are importable
+        require("telescope")
+        require("plenary")
+        require("cmp")
+        require("gitsigns")
+        require("nui.popup")
+      '';
+      assertions = [
+        {
+          assertion = pluginCount config.build.nvimPackage config.build.extraFiles "start" == 1;
+          message = "More than one plugin is defined in packpathDirs.";
+        }
+      ];
+    };
+
   # Test that optional plugins are handled
   optional-plugins =
     { config, ... }: