home: fish: use real .fish files for functions

home/default.nix

@@ -3,7 +3,7 @@
   imports = [
     ./alacritty.nix
     ./emacs.nix
-    ./fish.nix
+    ./fish
     ./flameshot.nix
     ./secrets
     ./starship.nix

home/fish.nix

@@ -1,25 +0,0 @@
-{ config, lib, ... }:
-let
-  cfg = config.my.home.fish;
-in
-{
-  options.my.home.fish.enable = lib.mkEnableOption "Fish shell";
-
-  config = lib.mkIf cfg.enable {
-    programs.fish = {
-      enable = true;
-      functions = {
-        nfl = {
-          body = ''
-            set -l flags "--commit-lock-file"
-            for flake in $argv
-                set -a flags "--update-input" "$flake"
-            end
-            nix flake lock $flags
-          '';
-          description = "convenience wrapper around `nix flake lock` to only update certain flake inputs";
-        };
-      };
-    };
-  };
-}

home/fish/default.nix

@@ -0,0 +1,15 @@
+{ config, lib, ... }:
+let
+  cfg = config.my.home.fish;
+in
+{
+  options.my.home.fish.enable = lib.mkEnableOption "Fish shell";
+
+  config = lib.mkIf cfg.enable {
+    programs.fish = {
+      enable = true;
+    };
+
+    xdg.configFile."fish/functions" = { source = ./. + "/functions"; };
+  };
+}

home/fish/functions/nfl.fish

@@ -0,0 +1,7 @@
+function nfl
+    set -l flags "--commit-lock-file"
+    for flake in $argv
+        set -a flags "--update-input" "$flake"
+    end
+    nix flake lock $flags
+end