#!/bin/bash
# Seeds the empty run workspace with a small home-library CLI (Node, node --test).
# Self-contained on purpose: the run cannot read the eval directory, and the
# fixture is written inline, with no path outside the workspace and no git.
set -eu
mkdir -p src bin tests
cat > package.json <<'J'
{ "name": "shelf", "version": "0.2.0", "type": "module", "private": true,
  "bin": { "shelf": "bin/shelf.mjs" },
  "scripts": { "test": "node --test", "lint": "node --check src/books.mjs" } }
J
cat > src/books.mjs <<'J'
// A tiny home-library catalogue kept in a JSON file.
import { readFileSync, writeFileSync, existsSync } from 'node:fs';

export function load(path) {
  return existsSync(path) ? JSON.parse(readFileSync(path, 'utf8')) : [];
}

export function save(path, books) {
  writeFileSync(path, JSON.stringify(books, null, 2) + '\n');
}

export function add(books, { title, author }) {
  if (!title) throw new Error('title is required');
  return [...books, { title, author: author ?? 'unknown', added: new Date().toISOString().slice(0, 10) }];
}
J
cat > bin/shelf.mjs <<'J'
#!/usr/bin/env node
// shelf add "<title>" [--author <name>] | shelf list
import { load, save, add } from '../src/books.mjs';

const file = process.env.SHELF_FILE ?? 'shelf.json';
const [cmd, ...rest] = process.argv.slice(2);

if (cmd === 'add') {
  const i = rest.indexOf('--author');
  const author = i >= 0 ? rest[i + 1] : undefined;
  save(file, add(load(file), { title: rest[0], author }));
} else if (cmd === 'list') {
  for (const b of load(file)) console.log(`${b.title} — ${b.author}`);
} else {
  console.error('usage: shelf add "<title>" [--author <name>] | shelf list');
  process.exit(2);
}
J
cat > tests/books.test.mjs <<'J'
import { test } from 'node:test';
import assert from 'node:assert/strict';
import { add } from '../src/books.mjs';

test('add appends a book', () => {
  const out = add([], { title: 'Dune', author: 'Herbert' });
  assert.equal(out.length, 1);
  assert.equal(out[0].author, 'Herbert');
});

test('add needs a title', () => assert.throws(() => add([], {}), /title is required/));
J