Vielzeug

Illusionist 3.0 ​

Illusionist 3 removes lifecycle methods from createIllusion() instances. Instances retain only their locale and pseudorandom generator state, own no external resources, and require no cleanup.

Remove disposal calls ​

Use an ordinary binding instead of using, and remove explicit cleanup calls.

ts
// Before
using illusion = createIllusion({ seed, locale });
const user = illusion.person.fullName();
ts
// After
const illusion = createIllusion({ seed, locale });
const user = illusion.person.fullName();

Remove reads or calls of:

  • dispose()
  • disposed
  • disposalSignal
  • [Symbol.dispose]()

Creating one instance per test remains useful for deterministic isolation, but no teardown step is required.

Validate custom random sources ​

Illusionist now validates values returned by consumer-provided RandomSource implementations. next() must return a finite number in [0, 1).

ts
const source: RandomSource = {
  next: () => 0.25,
};

Category helpers throw RangeError when a custom source returns NaN, an infinite value, a negative value, or 1 and above. Sources returned by createSeed() and mulberry32() already satisfy this contract.

Upgrade checklist ​

  • Replace using illusion with const illusion.
  • Remove lifecycle method calls and state checks.
  • Remove cleanup handlers that only disposed an Illusionist instance.
  • Ensure custom RandomSource.next() implementations return finite values in [0, 1).
  • Update @vielzeug/illusionist to version 3.