invariant

Callable

• invariant(condition: false, message?: null | string): never
• invariant(condition: boolean, message?: null | string): asserts condition

---

• Assert that condition is truthy, else throws Error { name: 'InvariantError', message }

  In production environment, message parameter could be stripped from source in order to reduce file size

  @example

  invariant(true, 'this should be true');// pass
  invariant(false, 'this should be true');// throw new Error('this should be true')