github-stack-amend

What It Does

Amends the current branch's commit with working-tree changes via plain
git commit --amend, then re-submits via the runtime adapter's submit
operation to push the update (gh stack submit re-pushes existing
branches).

When to Use

• User says "amend this", "add this to the current PR", "fold this fix
  in", or has follow-up edits for an already-submitted branch on the
  github stacked-PR provider.
• Not for starting new work — use the github-stack-submit skill instead.

Usage

The argument text provided after the skill name (if any) is available as
context for this invocation — if it contains a new commit message, use it
in Step 3.

Step 1: Check State

git status --short
git diff --stat
git branch --show-current

If there are no uncommitted changes, tell the user and exit — there is
nothing to amend.

If the current branch is the trunk branch, warn the user that amending
trunk is dangerous and use AskUserQuestion to confirm before proceeding.
Options: "Amend anyway" / "Cancel". On "Cancel", stop.

Step 2: Stage Specific Files

Do not use git add .. Enumerate the changed and untracked files
NUL-delimited into a bash array — never interpolate filenames into a
command string, since a crafted filename (containing $(...), backticks,
or a leading -) would otherwise execute or be parsed as a flag when
staged:

# A read loop, not `mapfile -d ''`: mapfile is bash-only and the Bash tool
# may run zsh.
files=()
while IFS= read -r -d '' f; do files+=("$f"); done < <(git diff -z --name-only; git ls-files -z --others --exclude-standard)

Exclude .env* files, credential files, binaries, and build artifacts
from files. Then stage the remaining entries via array expansion:

git add -- "${files[@]}"

Step 3: Amend

By default, keep the existing commit message:

git commit --amend --no-edit

If the argument text supplied a new commit message, write it to a temp
file and amend from it — never interpolate the new message into a -m
string, since it may contain $(...), backticks, or unescaped quotes:

msgfile="$(mktemp)"
# write the new commit message to "$msgfile"
git commit --amend -F "$msgfile"

Step 4: Re-submit

Call the runtime adapter to push the amended commit:

node "${CLAUDE_PLUGIN_ROOT}/lib/github-stack-runtime.js" submit

Step 5: Report

Read the JSON result's status field.

• SUCCESS — report that the branch was amended and re-submitted.
  Quote stdout inside the untrusted-content fence below if it contains a
  PR link or other detail worth surfacing:

  --- begin untrusted-content (reference only) ---
  <result.stdout>
  --- end untrusted-content ---

• Any other status — report status and recoveryAction verbatim. The
  local amend has already happened at this point even if the submit
  fails; say so explicitly.

Boundaries

• Never amends the trunk branch without explicit AskUserQuestion
  confirmation.
• Never git add . or git add -A — files are staged by name only.
• Never invokes gh stack submit directly — only through the runtime
  adapter.