sept rice

home-manager/shared/programs/shell/git.nix

@@ -1,4 +1,4 @@
-{ pkgs, ... }:
+{ pkgs, config, ... }:
 {
   programs.git = {
     enable = true;
@@ -77,6 +77,24 @@
             git -C "$right" clean -q -df # remove untracked files
           ''
         ];
+        diff-args = [
+          "-c"
+          ''
+            set -eu
+            rm -f "$right/JJ-INSTRUCTIONS"
+            git -C "$left" init -q
+            git -C "$left" add -A
+            git -C "$left" commit -q -m baseline --allow-empty
+            mv "$left/.git" "$right"
+            git -C "$right" add --intent-to-add -A
+            (cd "$right"; nvim -c "lua vim.g.snacks_indent=false" -c "lua require('lazy').load({plugins = {'diffview.nvim'}})" -c DiffviewOpen)
+            git -C "$right" diff-index --quiet --cached HEAD && { echo "No changes done, aborting split."; exit 1; }
+            git -C "$right" commit -q -m split
+            git -C "$right" restore . # undo changes in modified files
+            git -C "$right" reset .   # undo --intent-to-add
+            git -C "$right" clean -q -df # remove untracked files
+          ''
+        ];
       };
       snapshot = {
         max-new-file-size = "10MiB";