modules/performance: handle optional plugins when combining plugins

modules/top-level/output.nix

@@ -74,17 +74,45 @@ in
 
   config =
     let
+      # Plugin normalization
+      normalize =
+        p:
+        let
+          defaultPlugin = {
+            plugin = null;
+            config = "";
+            optional = false;
+          };
+        in
+        defaultPlugin // (if p ? plugin then p else { plugin = p; });
+      normalizePluginList = plugins: map normalize plugins;
+
+      # Normalized plugin list
+      normalizedPlugins = normalizePluginList config.extraPlugins;
+
       # Plugin list extended with dependencies
       allPlugins =
         let
-          pluginWithItsDeps = p: [ p ] ++ builtins.concatMap pluginWithItsDeps p.dependencies or [ ];
+          pluginWithItsDeps =
+            p: [ p ] ++ builtins.concatMap pluginWithItsDeps (normalizePluginList p.plugin.dependencies or [ ]);
         in
-        lib.unique (builtins.concatMap pluginWithItsDeps config.extraPlugins);
+        lib.unique (builtins.concatMap pluginWithItsDeps normalizedPlugins);
 
-      # All plugins with doc tags removed
-      allPluginsOverridden = map (
+      # Separated start and opt plugins
+      partitionedPlugins = builtins.partition (p: p.optional) allPlugins;
+      startPlugins = partitionedPlugins.wrong;
+      # Remove opt plugin dependencies since they are already available in start plugins
+      optPlugins = map (
+        p: p // { plugin = builtins.removeAttrs p.plugin [ "dependencies" ]; }
+      ) partitionedPlugins.right;
+
+      # Combine start plugins into a single pack
+      pluginPack =
+        let
+          # Plugins with doc tags removed
+          overriddenPlugins = map (
             plugin:
-        plugin.overrideAttrs (prev: {
+            plugin.plugin.overrideAttrs (prev: {
               nativeBuildInputs = lib.remove pkgs.vimUtils.vimGenDocHook prev.nativeBuildInputs or [ ];
               configurePhase = builtins.concatStringsSep "\n" (
                 builtins.filter (s: s != ":") [
@@ -93,20 +121,19 @@ in
                 ]
               );
             })
-      ) allPlugins;
+          ) startPlugins;
 
-      # Python3 dependencies from all plugins
+          # Python3 dependencies
           python3Dependencies =
             let
-          deps = map (p: p.python3Dependencies or (_: [ ])) allPluginsOverrided;
+              deps = map (p: p.plugin.python3Dependencies or (_: [ ])) startPlugins;
             in
             ps: builtins.concatMap (f: f ps) deps;
-
-      # Combine all plugins into a single pack
-      pluginPack = pkgs.vimUtils.toVimPlugin (
+        in
+        pkgs.vimUtils.toVimPlugin (
           pkgs.buildEnv {
             name = "plugin-pack";
-          paths = allPluginsOverridden;
+            paths = overriddenPlugins;
             inherit (config.performance.combinePlugins) pathsToLink;
             # Remove empty directories and activate vimGenDocHook
             postBuild = ''
@@ -120,18 +147,10 @@ in
         );
 
       # Combined plugins
-      combinedPlugins = [ pluginPack ];
+      combinedPlugins = [ (normalize pluginPack) ] ++ optPlugins;
 
       # Plugins to use in finalPackage
-      plugins = if config.performance.combinePlugins.enable then combinedPlugins else config.extraPlugins;
-
-      defaultPlugin = {
-        plugin = null;
-        config = "";
-        optional = false;
-      };
-
-      normalizedPlugins = map (x: defaultPlugin // (if x ? plugin then x else { plugin = x; })) plugins;
+      plugins = if config.performance.combinePlugins.enable then combinedPlugins else normalizedPlugins;
 
       neovimConfig = pkgs.neovimUtils.makeNeovimConfig (
         {
@@ -144,7 +163,7 @@ in
             withNodeJs
             ;
           # inherit customRC;
-          plugins = normalizedPlugins;
+          inherit plugins;
         }
         # Necessary to make sure the runtime path is set properly in NixOS 22.05,
         # or more generally before the commit:
@@ -152,7 +171,7 @@ in
         // optionalAttrs (lib.functionArgs pkgs.neovimUtils.makeNeovimConfig ? configure) {
           configure.packages = {
             nixvim = {
-              start = map (x: x.plugin) normalizedPlugins;
+              start = map (x: x.plugin) plugins;
               opt = [ ];
             };
           };

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

@@ -129,4 +129,66 @@
         }
       ];
     };
+
+  # Test that optional plugins are handled
+  optional-plugins.module =
+    { config, ... }:
+    {
+      performance.combinePlugins.enable = true;
+      extraPlugins = with pkgs.vimPlugins; [
+        # Start plugins
+        plenary-nvim
+        nvim-lspconfig
+        # Optional plugin
+        {
+          plugin = nvim-treesitter;
+          optional = true;
+        }
+        # Optional plugin with dependency on plenary-nvim
+        # Dependencies should not be duplicated
+        {
+          plugin = telescope-nvim;
+          optional = true;
+        }
+      ];
+      extraConfigLuaPost = ''
+        -- Start plugins are loadable
+        require("plenary")
+        require("lspconfig")
+
+        -- Opt plugins are not loadable
+        local ok = pcall(require, "nvim-treesitter")
+        assert(not ok, "nvim-treesitter plugin is loadable")
+        ok = pcall(require, "telescope")
+        assert(not ok, "telescope-nvim plugin is loadable")
+
+        -- Load plugins
+        vim.cmd.packadd("nvim-treesitter")
+        vim.cmd.packadd("telescope.nvim")
+
+        -- Now opt plugins are loadable
+        require("nvim-treesitter")
+        require("telescope")
+
+        -- Only one copy of plenary-nvim should be available
+        assert(
+          #vim.api.nvim_get_runtime_file("lua/plenary/init.lua", true) == 1,
+          "plenary-nvim is duplicated"
+        )
+      '';
+      assertions =
+        let
+          packages = config.finalPackage.packpathDirs.myNeovimPackages;
+        in
+        [
+          {
+            assertion = builtins.length packages.start == 1;
+            message = "More than one start plugin is defined in packpathDirs";
+          }
+          {
+            assertion = builtins.length packages.opt == 2;
+            message = "Less than two opt plugins are defined in packpathDirs";
+          }
+        ];
+    };
 }