유틸리티 타입 해부

// 유틸리티 타입 시뮬레이션
  const unitBase = { model: 'T-800', threat: 8, status: 'ACTIVE', location: 'LA' };

  // Partial<Unit> - 모든 속성 선택적
  function updateUnit(base, partial) { return { ...base, ...partial }; }

  // Pick<Unit, 'model' | 'threat'>
  function pickUnit(unit, keys) { return Object.fromEntries(keys.map(k => [k, unit[k]])); }

  // Omit<Unit, 'location'>
  function omitUnit(unit, keys) { return Object.fromEntries(Object.entries(unit).filter(([k]) => !keys.includes(k))); }

  const results = [
    { type: 'Partial — 부분 업데이트', result: JSON.stringify(updateUnit(unitBase, { status: 'OFFLINE' })) },
    { type: 'Pick — 선택 속성만', result: JSON.stringify(pickUnit(unitBase, ['model', 'threat'])) },
    { type: 'Omit — 특정 속성 제외', result: JSON.stringify(omitUnit(unitBase, ['location'])) },
  ];

  results.forEach(r => {
    const el = document.createElement('div');
    el.style.marginBottom = '8px'; el.style.fontSize = '11px';
    el.innerHTML = `<div style="color:#f59e0b;">${r.type}</div><div style="color:#888; font-size:10px; word-break:break-all;">${r.result}</div>`;
    document.currentScript.parentElement.appendChild(el);
  });