fish: add develop function

modules/home/console/shell/fish/default.nix

@@ -13,6 +13,7 @@ in {
     ./plugins.nix
     ./binds.nix
     ./aliases.nix
+    ./functions
   ];
 
   options.ooknet.home.fish.enable = mkEnableOption "";

modules/home/console/shell/fish/functions/default.nix

@@ -0,0 +1,5 @@
+{
+  imports = [
+    ./develop.nix
+  ];
+}

modules/home/console/shell/fish/functions/develop.nix

@@ -0,0 +1,31 @@
+{
+  self,
+  pkgs,
+  ...
+}: let
+  # get devshell names from flake
+  devShellNames = builtins.concatStringsSep " " (builtins.attrNames self.devShells.${pkgs.system});
+in {
+  programs.fish = {
+    # add devshells completions to init script
+    interactiveShellInit = ''
+      complete -c develop -f -a "${devShellNames}"
+    '';
+    functions.develop = {
+      description = "Easily jump into any of the ooknet devshells";
+      body =
+        #fish
+        ''
+          if test -n "$argv[1]"
+            if test -n "$FLAKE"
+              nix develop $FLAKE#$argv[1]
+            else
+              echo "error: FLAKE variable is not set";
+            end
+          else
+            echo "error: No argument was provided";
+          end
+        '';
+    };
+  };
+}