'use strict';
const assert = require('node:assert');
const { capImage } = require('../lib/image-cap');

let passed = 0;
function check(name, fn) {
  try { fn(); console.log('  ok -', name); passed++; }
  catch (e) { console.error('  FAIL -', name, e.message); process.exitCode = 1; }
}

check('small buffer returned untouched', () => {
  const buf = Buffer.alloc(1024); // 1 KB
  const r = capImage(buf);
  assert.strictEqual(r.buf, buf, 'small images should not be modified');
  assert.strictEqual(r.preview, null);
});

check('oversized buffer triggers preview placeholder', () => {
  const buf = Buffer.alloc(3 * 1024 * 1024); // 3 MB
  const r = capImage(buf);
  assert.ok(r.preview !== null, 'oversized images should produce preview');
  assert.strictEqual(r.preview, '[图片]');
});