greview - PR code review in worktrees with Claude

greview

#!/usr/bin/env bun

const USAGE = `greview - PR code review in worktrees with Claude

Usage:
  greview <github-url|graphite-url|pr-number>

Examples:
  greview https://github.com/gamma-app/gamma/pull/4521
  greview https://app.graphite.com/github/pr/gamma-app/gamma/4521
  greview 4521

Note: run from the target repo directory. Worktree is cleaned up on exit.`;

function parsePR(input: string): number | null {
  if (/^\d+$/.test(input)) return parseInt(input);

  // github.com/owner/repo/pull/123
  const gh = input.match(/github\.com\/[^/]+\/[^/]+\/pull\/(\d+)/);
  if (gh) return parseInt(gh[1]);

  // app.graphite.com/github/pr/owner/repo/123
  const gr = input.match(/graphite\.(?:com|dev)\/github\/pr\/[^/]+\/[^/]+\/(\d+)/);
  if (gr) return parseInt(gr[1]);

  return null;
}

async function prBranch(pr: number): Promise<string> {
  const proc = Bun.spawn(
    ["gh", "pr", "view", String(pr), "--json", "headRefName", "-q", ".headRefName"],
    { stdout: "pipe", stderr: "pipe" }
  );
  const out = await new Response(proc.stdout).text();
  const code = await proc.exited;
  if (code !== 0) {
    console.error(`failed to resolve branch for PR #${pr}`);
    process.exit(1);
  }
  return out.trim();
}

const input = process.argv[2];
if (!input || input === "--help" || input === "-h") {
  console.log(USAGE);
  process.exit(input ? 0 : 1);
}

const pr = parsePR(input);
if (!pr) {
  console.error(`cannot parse PR number from: ${input}`);
  process.exit(1);
}

const prompt = [
  `Load context for PR #${pr}:`,
  `1. \`gh pr view ${pr} --json title,body,url\` to get PR info`,
  `2. \`gh pr diff ${pr}\` to see the diff`,
  `3. \`gh api repos/{owner}/{repo}/pulls/${pr}/comments\` and \`gh api repos/{owner}/{repo}/pulls/${pr}/reviews\` to load review comments`,
  `4. Read the changed files for full context`,
  ``,
  `You are in a worktree checked out to the PR's branch, so you can read any file directly.`,
  `Once loaded, just say "Ready" and wait for my questions. Do not review or summarize unless asked.`,
].join("\n");

// resolve branch before launching so we can clean up after
const branch = await prBranch(pr);

const proc = Bun.spawn(
  ["wt", "switch", `pr:${pr}`, "-x", "claude", "--", "--dangerously-skip-permissions", prompt],
  { stdio: ["inherit", "inherit", "inherit"] }
);
await proc.exited;

// cleanup worktree after claude exits
const rm = Bun.spawn(["wt", "remove", "-D", branch], {
  stdio: ["inherit", "inherit", "inherit"],
});
await rm.exited;