frontend-pr-screenshot

name	frontend-pr-screenshot
description	Capture a screenshot of the frontend app and post it to the current GitHub pull request. Use when a user asks to post a PR screenshot, show the UI in a PR comment, verify visual changes in a PR, or include visual evidence after UI work.
allowed-tools	Bash(gh *), Bash(git *), Bash(curl *), Bash(npx playwright*), Bash(lsof *), Bash(pnpm *), Bash(kill *), Bash(sleep *), Bash(seq *), Bash(cat *), Bash(date *), Bash(printf *)

frontend-pr-screenshot

Posts a live screenshot of the frontend chat app to the active GitHub PR.

Workflow

1 — Verify open PR

PR_NUMBER=$(gh pr view --json number -q '.number' 2>/dev/null)
# If this fails, tell the user to open a PR first and stop.

2 — Ensure dev server on port 3000

if ! lsof -ti:3000 > /dev/null 2>&1; then
  cd frontend && pnpm run dev &
  DEV_PID=$!
  READY=0
  for i in $(seq 1 30); do
    curl -sf http://localhost:3000 > /dev/null 2>&1 && READY=1 && break
    sleep 1
  done
  [ "$READY" -eq 0 ] && echo "Dev server unreachable after 30 s" && exit 1
fi

3 — Screenshot with Playwright

The app defaults to dark mode when no OS preference is detected. Pass --color-scheme dark so headless Chromium matches.

cd frontend && npx playwright screenshot \
  "http://localhost:3000/chat" \
  /tmp/frontend-screenshot.png \
  --wait-for-selector "#message-input" \
  --color-scheme dark \
  --timeout 15000

Install if missing: pnpm exec playwright install chromium --with-deps

4 — Post PR comment

gh pr comment --attach (gh ≥ 2.99.0) uploads the local file and rewrites the matching Markdown reference in place, so no release asset or public URL is needed. Do NOT commit screenshots to the repo (.github/pr-assets/ is gitignored).

DATE_UTC=$(date -u '+%Y-%m-%d %H:%M UTC')
gh pr comment "$PR_NUMBER" \
  --attach '/tmp/frontend-screenshot.png#App screenshot' \
  --body "$(cat <<EOF
## Frontend Screenshot

![App screenshot](/tmp/frontend-screenshot.png)

> Captured from /chat — ${DATE_UTC}
EOF
)"

5 — Clean up

If you started the dev server in step 2:

[ -n "$DEV_PID" ] && kill "$DEV_PID" 2>/dev/null || true