present-pr

Turn the current branch's PR (or commit range) into a deck_doctor-green premium deck grounded in the real diff — no invented content, no placeholder slides. This funnels into the existing premium-presentations skill pipeline verbatim: new-deck.sh → spec → generate → deck_doctor.py. Do not emit slides directly and do not bypass the spec contract.

0. Set provider paths

Claude Code keeps the installed plugin immutable. Capture its bundled skill from CLAUDE_PLUGIN_ROOT, and write every generated artifact beneath the active project in CLAUDE_PROJECT_DIR:

plugin_root="${CLAUDE_PLUGIN_ROOT}"
if [ -z "$plugin_root" ]; then
  echo "present-pr: CLAUDE_PLUGIN_ROOT is required" >&2
  exit 1
fi
skill_root="$plugin_root/skills/premium-presentations"
project_root="${CLAUDE_PROJECT_DIR}"
if [ -z "$project_root" ]; then
  echo "present-pr: CLAUDE_PROJECT_DIR is required" >&2
  exit 1
fi
deck_root="$project_root/assets/decks"
themes_css="$project_root/assets/shared/premium-themes.css"
if [ ! -f "$themes_css" ]; then
  themes_css="$skill_root/assets/shared/premium-themes.css"
fi
cd "$project_root"

The cd is deliberately after both roots are captured. All subsequent commands use these absolute paths; do not substitute cwd-relative skills/premium-presentations paths.

1. Determine the base ref

Resolve one base commit and reuse it for every diff/log below — never inline a literal main in the git commands themselves, since main may not exist locally (worktrees, orphan branches, shallow clones).

resolve_base() {
  # 1. Explicit argument always wins.
  if [ -n "$1" ]; then
    echo "$1"
    return 0
  fi
  # 2. Real PR ancestry: where this branch forked from main.
  local fork_point
  fork_point="$(git merge-base --fork-point main HEAD 2>/dev/null)"
  if [ -n "$fork_point" ]; then
    echo "$fork_point"
    return 0
  fi
  # 3. main exists locally and actually diverges from HEAD (not just a
  #    missing fork-point cache entry, e.g. a shallow clone).
  if git show-ref --verify --quiet refs/heads/main; then
    local mb head
    mb="$(git merge-base main HEAD 2>/dev/null)"
    head="$(git rev-parse HEAD)"
    if [ -n "$mb" ] && [ "$mb" != "$head" ]; then
      echo "$mb"
      return 0
    fi
  fi
  # 4. No usable main (orphan branch, worktree without main, or HEAD==main):
  #    the same synthetic stand-in the skill's own test fixtures use.
  if git rev-parse --verify --quiet HEAD~3 >/dev/null 2>&1; then
    echo "HEAD~3"
    return 0
  fi
  # 5. History too short even for HEAD~3 (shallow clone, brand-new repo):
  #    fall back to the root commit, or fail loudly rather than guess.
  local root
  root="$(git rev-list --max-parents=0 HEAD 2>/dev/null | tail -1)"
  if [ -n "$root" ] && [ "$root" != "$(git rev-parse HEAD)" ]; then
    echo "$root"
    return 0
  fi
  echo "present-pr: cannot resolve a comparison base — no main branch, no fork-point, and fewer than 3 commits of history. Pass an explicit base ref: /present-pr <base>" >&2
  return 1
}

base="$(resolve_base "$1")" || exit 1