wrappers: make _shared.nix return a module

wrappers/_shared.nix

@@ -1,37 +1,65 @@
-helpers:
+{
+  # Our helpers
+  helpers,
+  # Option path where extraFiles should go
+  filesOpt ? null,
+  # Filepath prefix to apply to extraFiles
+  filesPrefix ? "nvim/",
+  # Filepath to use when adding `cfg.initPath` to `filesOpt`
+  # Is prefixed with `filesPrefix`
+  initName ? "init.lua",
+}:
 { lib, config, ... }:
 let
   inherit (lib)
     isAttrs
     listToAttrs
     map
+    mkIf
+    mkMerge
     mkOption
     mkOptionType
+    optionalAttrs
+    setAttrByPath
     ;
   cfg = config.programs.nixvim;
   extraFiles = lib.filter (file: file.enable) (lib.attrValues cfg.extraFiles);
 in
 {
-  helpers = mkOption {
-    type = mkOptionType {
-      name = "helpers";
-      description = "Helpers that can be used when writing nixvim configs";
-      check = isAttrs;
+  options = {
+    nixvim.helpers = mkOption {
+      type = mkOptionType {
+        name = "helpers";
+        description = "Helpers that can be used when writing nixvim configs";
+        check = isAttrs;
+      };
+      description = "Use this option to access the helpers";
     };
-    description = "Use this option to access the helpers";
-    default = helpers;
   };
 
-  # extraFiles, but nested under "nvim/" for use in etc/xdg config
-  configFiles = listToAttrs (
-    map (
-      { target, source, ... }:
-      {
-        name = "nvim/" + target;
-        value = {
-          inherit source;
-        };
-      }
-    ) extraFiles
-  );
+  config = mkMerge [
+    # Make our lib available to the host modules
+    { nixvim.helpers = lib.mkDefault helpers; }
+    # Propagate extraFiles to the host modules
+    (optionalAttrs (filesOpt != null) (
+      mkIf (!cfg.wrapRc) (
+        setAttrByPath filesOpt (
+          listToAttrs (
+            map (
+              { target, source, ... }:
+              {
+                name = filesPrefix + target;
+                value = {
+                  inherit source;
+                };
+              }
+            ) extraFiles
+          )
+          // {
+            ${filesPrefix + initName}.source = cfg.initPath;
+          }
+        )
+      )
+    ))
+  ];
 }