plugins/lazy.nvim: new plugin manager (#1175)

plugins/default.nix

@@ -94,6 +94,7 @@
     ./dap
 
     ./pluginmanagers/packer.nix
+    ./pluginmanagers/lazy.nix
 
     ./snippets/friendly-snippets.nix
     ./snippets/luasnip

plugins/filetrees/nvim-tree.nix

@@ -759,7 +759,7 @@ in {
             helpers.defaultNullOpts.mkNullable (with types; attrsOf (listOf str))
             ''
               {
-                filetype = [ "notify" "packer" "qf" "diff" "fugitive" "fugitiveblame" ];
+                filetype = [ "notify" "lazy" "packer" "qf" "diff" "fugitive" "fugitiveblame" ];
                 buftype = [ "nofile" "terminal" "help" ];
               };
             ''

plugins/pluginmanagers/lazy.nix

@@ -0,0 +1,224 @@
+{
+  lib,
+  helpers,
+  config,
+  pkgs,
+  ...
+}:
+with lib; let
+  cfg = config.plugins.lazy;
+  lazyPlugins = cfg.plugins;
+
+  processPlugin = plugin: let
+    mkEntryFromDrv = p:
+      if lib.isDerivation p
+      then {
+        name = "${lib.getName p}";
+        path = p;
+      }
+      else {
+        name = "${lib.getName p.pkg}";
+        path = p.pkg;
+      };
+    processDependencies =
+      if plugin ? dependencies && plugin.dependencies != null
+      then builtins.concatMap processPlugin plugin.dependencies
+      else [];
+  in
+    [(mkEntryFromDrv plugin)] ++ processDependencies;
+
+  processedPlugins = builtins.concatLists (builtins.map processPlugin lazyPlugins);
+  lazyPath = pkgs.linkFarm "lazy-plugins" processedPlugins;
+in {
+  options = {
+    plugins.lazy = {
+      enable = mkEnableOption "lazy.nvim";
+
+      plugins = with types; let
+        pluginType =
+          either
+          package
+          (submodule {
+            options = {
+              dir = helpers.mkNullOrOption str "A directory pointing to a local plugin";
+
+              pkg = mkOption {
+                type = package;
+                description = "Vim plugin to install";
+              };
+
+              name = helpers.mkNullOrOption str "Name of the plugin to install";
+
+              dev = helpers.defaultNullOpts.mkBool false ''
+                When true, a local plugin directory will be used instead.
+                See config.dev
+              '';
+
+              lazy = helpers.defaultNullOpts.mkBool true ''
+                When true, the plugin will only be loaded when needed.
+                Lazy-loaded plugins are automatically loaded when their Lua modules are required,
+                or when one of the lazy-loading handlers triggers
+              '';
+
+              enabled = helpers.defaultNullOpts.mkStrLuaFnOr types.bool "`true`" ''
+                When false then this plugin will not be included in the spec. (accepts fun():boolean)
+              '';
+
+              cond =
+                helpers.defaultNullOpts.mkStrLuaFnOr types.bool "`true`"
+                ''
+                  When false, or if the function returns false,
+                  then this plugin will not be loaded. Useful to disable some plugins in vscode,
+                  or firenvim for example. (accepts fun(LazyPlugin):boolean)
+                '';
+
+              dependencies =
+                helpers.mkNullOrOption (helpers.nixvimTypes.eitherRecursive str listOfPlugins)
+                "Plugin dependencies";
+
+              init =
+                helpers.mkNullOrLuaFn
+                "init functions are always executed during startup";
+
+              config = helpers.mkNullOrStrLuaFnOr (types.enum [true]) ''
+                config is executed when the plugin loads.
+                The default implementation will automatically run require(MAIN).setup(opts).
+                Lazy uses several heuristics to determine the plugin's MAIN module automatically based on the plugin's name.
+                See also opts. To use the default implementation without opts set config to true.
+              '';
+
+              main = helpers.mkNullOrOption str ''
+                You can specify the main module to use for config() and opts(),
+                in case it can not be determined automatically. See config()
+              '';
+
+              submodules = helpers.defaultNullOpts.mkBool true ''
+                When false, git submodules will not be fetched.
+                Defaults to true
+              '';
+
+              event = with helpers.nixvimTypes;
+                helpers.mkNullOrOption (maybeRaw (either str (listOf str)))
+                "Lazy-load on event. Events can be specified as BufEnter or with a pattern like BufEnter *.lua";
+
+              cmd = with helpers.nixvimTypes;
+                helpers.mkNullOrOption (maybeRaw (either str (listOf str)))
+                "Lazy-load on command";
+
+              ft = with helpers.nixvimTypes;
+                helpers.mkNullOrOption (maybeRaw (either str (listOf str)))
+                "Lazy-load on filetype";
+
+              keys = with helpers.nixvimTypes;
+                helpers.mkNullOrOption (maybeRaw (either str (listOf str)))
+                "Lazy-load on key mapping";
+
+              module = helpers.mkNullOrOption (enum [false]) ''
+                Do not automatically load this Lua module when it's required somewhere
+              '';
+
+              priority = helpers.mkNullOrOption number ''
+                Only useful for start plugins (lazy=false) to force loading certain plugins first.
+                Default priority is 50. It's recommended to set this to a high number for colorschemes.
+              '';
+
+              optional = helpers.defaultNullOpts.mkBool false ''
+                When a spec is tagged optional, it will only be included in the final spec,
+                when the same plugin has been specified at least once somewhere else without optional.
+                This is mainly useful for Neovim distros, to allow setting options on plugins that may/may not be part
+                of the user's plugins
+              '';
+
+              opts = with helpers.nixvimTypes;
+                helpers.mkNullOrOption (maybeRaw (attrsOf anything)) ''
+                  opts should be a table (will be merged with parent specs),
+                  return a table (replaces parent specs) or should change a table.
+                  The table will be passed to the Plugin.config() function.
+                  Setting this value will imply Plugin.config()
+                '';
+            };
+          });
+
+        listOfPlugins = types.listOf pluginType;
+      in
+        mkOption {
+          type = listOfPlugins;
+          default = [];
+          description = "List of plugins";
+        };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    extraPlugins = [pkgs.vimPlugins.lazy-nvim];
+    extraPackages = [pkgs.git];
+
+    extraConfigLua = let
+      pluginToLua = plugin: let
+        keyExists = keyToCheck: attrSet: lib.elem keyToCheck (lib.attrNames attrSet);
+      in
+        if isDerivation plugin
+        then {
+          dir = "${lazyPath}/${lib.getName plugin}";
+        }
+        else {
+          "__unkeyed" = plugin.name;
+
+          inherit
+            (plugin)
+            cmd
+            cond
+            config
+            dev
+            enabled
+            event
+            ft
+            init
+            keys
+            lazy
+            main
+            module
+            name
+            optional
+            opts
+            priority
+            submodules
+            ;
+
+          dependencies =
+            helpers.ifNonNull' plugin.dependencies
+            (
+              if isList plugin.dependencies
+              then (pluginListToLua plugin.dependencies)
+              else plugin.dependencies
+            );
+
+          dir =
+            if plugin ? dir && plugin.dir != null
+            then plugin.dir
+            else "${lazyPath}/${lib.getName plugin.pkg}";
+        };
+
+      pluginListToLua = map pluginToLua;
+
+      plugins = pluginListToLua cfg.plugins;
+
+      packedPlugins =
+        if length plugins == 1
+        then head plugins
+        else plugins;
+    in
+      mkIf (cfg.plugins != []) ''
+        require('lazy').setup(
+          {
+            dev = {
+              path = "${lazyPath}",
+              patterns = {"."},
+              fallback = false
+            },
+            spec = ${helpers.toLuaObject packedPlugins}
+          }
+        )
+      '';
+  };
+}

tests/test-sources/plugins/pluginmanagers/lazy.nix

@@ -0,0 +1,72 @@
+{pkgs, ...}: {
+  # Empty configuration
+  empty = {
+    plugins.lazy.enable = true;
+  };
+
+  test = {
+    plugins.lazy = with pkgs.vimPlugins; {
+      enable = true;
+
+      plugins = [
+        vim-closer
+
+        # Load on specific commands
+        {
+          pkg = vim-dispatch;
+          optional = true;
+          cmd = ["Dispatch" "Make" "Focus" "Start"];
+        }
+
+        # Load on an autocommand event
+        {
+          pkg = vim-matchup;
+          event = "VimEnter";
+        }
+
+        # Load on a combination of conditions: specific filetypes or commands
+        {
+          pkg = ale;
+          name = "w0rp/ale";
+          ft = ["sh" "zsh" "bash" "c" "cpp" "cmake" "html" "markdown" "racket" "vim" "tex"];
+          cmd = "ALEEnable";
+        }
+
+        # Plugins can have dependencies on other plugins
+        {
+          pkg = completion-nvim;
+          optional = true;
+          dependencies = [
+            {
+              pkg = vim-vsnip;
+              optional = true;
+            }
+            {
+              pkg = vim-vsnip-integ;
+              optional = true;
+            }
+          ];
+        }
+
+        # Plugins can have post-install/update hooks
+        {
+          pkg = markdown-preview-nvim;
+          cmd = "MarkdownPreview";
+        }
+
+        # Post-install/update hook with neovim command
+        {
+          pkg = nvim-treesitter;
+          opts = {ensure_installed = {};};
+        }
+
+        # Use dependency and run lua function after load
+        {
+          pkg = gitsigns-nvim;
+          dependencies = [plenary-nvim];
+          config = ''function() require("gitsigns").setup() end'';
+        }
+      ];
+    };
+  };
+}