From 880efe7fc4ba40ef704cc2de88d120c6ae4c6a6b Mon Sep 17 00:00:00 2001
From: Shun Kakinoki <shunkakinoki@gmail.com>
Date: Mon, 12 Jan 2026 00:15:18 +0900
Subject: [PATCH] feat(fish): add global dev command for nix devshell

Add a `dev` fish abbreviation that enters a Nix development shell from
anywhere. The function searches for the nearest flake.nix in parent
directories and uses that devshell, or falls back to ~/dotfiles if no
flake is found.
---
 home-manager/programs/fish/default.nix        |  2 ++
 .../fish/functions/_dev_function.fish         | 23 +++++++++++++++++++
 2 files changed, 25 insertions(+)
 create mode 100644 home-manager/programs/fish/functions/_dev_function.fish

diff --git a/home-manager/programs/fish/default.nix b/home-manager/programs/fish/default.nix
index af1856f61..7147f438a 100644
--- a/home-manager/programs/fish/default.nix
+++ b/home-manager/programs/fish/default.nix
@@ -65,6 +65,7 @@
       coxeh = "_coxeh_function";
       coxel = "_coxel_function";
       coxelh = "_coxelh_function";
+      dev = "_dev_function";
       ocxe = "_ocxe_function";
       ocxeh = "_ocxeh_function";
       gco = "_gco_function";
@@ -137,6 +138,7 @@
         "_coxeh_function"
         "_coxel_function"
         "_coxelh_function"
+        "_dev_function"
         "_ocxe_function"
         "_ocxeh_function"
         "_fish_shortcuts"
diff --git a/home-manager/programs/fish/functions/_dev_function.fish b/home-manager/programs/fish/functions/_dev_function.fish
new file mode 100644
index 000000000..08708a344
--- /dev/null
+++ b/home-manager/programs/fish/functions/_dev_function.fish
@@ -0,0 +1,23 @@
+function _dev_function --description "Enter Nix development shell"
+    # Find the nearest directory with flake.nix, or use dotfiles
+    set -l target_dir ""
+
+    # Check if current directory or any parent has flake.nix
+    set -l check_dir (pwd)
+    while test "$check_dir" != "/"
+        if test -f "$check_dir/flake.nix"
+            set target_dir $check_dir
+            break
+        end
+        set check_dir (dirname $check_dir)
+    end
+
+    # Fallback to dotfiles if no flake found
+    if test -z "$target_dir"
+        set target_dir "$HOME/dotfiles"
+    end
+
+    # Enter the devshell
+    echo "Entering devshell in $target_dir"
+    DEVENV_ROOT=$target_dir nix develop $target_dir $argv
+end