fix(nixos): deploy local worktree changes

configs/nixos/modules/shell/fish/functions/deploy-to.fish

@@ -5,31 +5,51 @@ end
 
 set host $argv[1]
 set branch $argv[2]
+set branch_source explicit
 
 if test -z "$branch"
+    set branch_source current
     set branch (git branch --show-current)
 end
 
-if test -z "$branch"
-    echo "deploy-to: could not determine the current branch" >&2
-    return 2
-end
-
 git rev-parse --show-toplevel >/dev/null 2>&1
 or begin
     echo "deploy-to: run this from a git checkout" >&2
     return 2
 end
 
-set dirty_lines (git status --porcelain)
-if test (count $dirty_lines) -gt 0
-    echo "deploy-to: refusing to deploy with a dirty local worktree" >&2
+set untracked_lines (git status --porcelain --untracked-files=normal | string match -r '^\?\? ')
+if test (count $untracked_lines) -gt 0
+    echo "deploy-to: refusing to deploy untracked files" >&2
+    echo "deploy-to: git add new files that Nix must see, or remove them" >&2
     return 1
 end
 
 git fetch origin
 or return $status
 
+if test -z "$branch"; or not git rev-parse --verify --quiet refs/remotes/origin/$branch >/dev/null
+    if test "$branch_source" = explicit
+        echo "deploy-to: origin/$branch does not exist" >&2
+        return 1
+    end
+
+    set branch_source upstream
+    set upstream_ref (git rev-parse --abbrev-ref --symbolic-full-name '@{upstream}' 2>/dev/null)
+    set branch (string replace -r '^origin/' '' -- $upstream_ref)
+end
+
+if test -z "$branch"; or not git rev-parse --verify --quiet refs/remotes/origin/$branch >/dev/null
+    set branch_source default
+    set origin_head (git symbolic-ref --quiet --short refs/remotes/origin/HEAD 2>/dev/null)
+    set branch (string replace -r '^origin/' '' -- $origin_head)
+end
+
+if test -z "$branch"
+    echo "deploy-to: could not determine a deploy branch" >&2
+    return 2
+end
+
 set remote_ref refs/remotes/origin/$branch
 git rev-parse --verify --quiet $remote_ref >/dev/null
 or begin
@@ -37,17 +57,37 @@ or begin
     return 1
 end
 
-set local_head (git rev-parse HEAD)
-set remote_head (git rev-parse $remote_ref)
-
-if test "$local_head" != "$remote_head"
-    echo "deploy-to: local HEAD differs from origin/$branch" >&2
-    echo "deploy-to: push or reset the branch before deploying" >&2
-    return 1
+set has_local_changes false
+if not git diff --quiet $remote_ref --
+    set has_local_changes true
 end
 
 set escaped_branch (string escape -- $branch)
 set escaped_host (string escape -- $host)
-set remote_command "cd ~/dev && git fetch origin && git switch -- $escaped_branch && git reset --hard origin/$escaped_branch && sudo nixos-rebuild switch --flake .#$escaped_host --print-build-logs"
+set remote_command "cd ~/dev && git fetch origin && git switch -- $escaped_branch && git reset --hard origin/$escaped_branch && git clean -fd"
+
+set patch_file ""
+set remote_patch_file ""
+if test "$has_local_changes" = true
+    set patch_file (mktemp)
+    set remote_patch_file "/tmp/deploy-to-$host.patch"
+    git diff --binary $remote_ref -- >$patch_file
+    or begin
+        rm -f $patch_file
+        return $status
+    end
+
+    scp $patch_file $host:$remote_patch_file
+    set scp_status $status
+    rm -f $patch_file
+    if test $scp_status -ne 0
+        return $scp_status
+    end
+
+    set escaped_remote_patch_file (string escape -- $remote_patch_file)
+    set remote_command "$remote_command && git apply --index $escaped_remote_patch_file && rm -f $escaped_remote_patch_file"
+end
+
+set remote_command "$remote_command && sudo nixos-rebuild switch --flake .#$escaped_host --print-build-logs"
 
 ssh -t $host $remote_command