Override the worker constructor — useful for tests or custom bundlers.
May return a Worker synchronously or a Promise resolving to one; the
client handles both. Sync callbacks remain the common case and stay
type-compatible with the previous signature.
Override the worker constructor — useful for tests or custom bundlers. May return a Worker synchronously or a Promise resolving to one; the client handles both. Sync callbacks remain the common case and stay type-compatible with the previous signature.