Use LLMs to generate a PR summary

prompt-pr.sh

#!/usr/bin/env bash
# Generates a prompt for a PR summary and copies it to clipboard.
#
# Usage: prompt-pr.sh 1234
#
# Paste into Claude and watch it generate a PR summary.
#
# Try following up with these questions:
#
# - given the PR description and this plan, is there anything in this PR that may need changing?
# - what are pros and cons of this change?
#
# More ideas: enhance this prompt with a repo map and a CONVENTIONS.md file
#
# <repo_map>
# $(aider --sonnet --no-show-model-warnings --show-repo-map)
# </repo_map>
#
# <conventions>
# $(cat CONVENTIONS.md)
# </conventions>

set -e

if [[ -z "$1" ]]; then
  echo "Error: Please provide a PR number"
  exit 1
fi

pr_number="$1"

copy_to_clipboard() {
  if command -v pbcopy >/dev/null 2>&1; then
    pbcopy # macOS
  elif command -v wl-copy >/dev/null 2>&1; then
    wl-copy # Wayland
  else
    echo "No clipboard command found"
    exit 1
  fi
}

cat <<EOF | copy_to_clipboard
Assist in tasks involving a Git repository.
Pull request details may be provided in <pr_diff>.
Pull request info may be provided in <pr_info>.

Context:

- I am reviewing a pull request.
- I need help summarising it. Reverse-engineer a possible plan that led to these changes.

Steps to do:

- Print out a draft of this reverse-engineered plan.

The plan should:

- Be a spec for an LLM assistant to carry out a task
- Have enough information for an LLM assistant to accomplish the task
- Have ambiguities answered
- Have a "Context" heading that describes info that relates to the task
- Have an "Objectives" heading with a list of high-level actions to do
- Have an "Actions" heading with a list of files and functions and the changes to be made to them
- Have an "Out of scope" heading for a list of things not to do (optional)

<pr_info>

$(gh pr view "$pr_number")

</pr_info>

<pr_diff>

$(gh pr diff "$pr_number")

</pr_diff>
EOF

echo "Prompt copied to clipboard ✓"