assertRpcErr<T, E extends BaseError>(expectedErrorNameOrCtor?: string | TrellisTestErrorConstructor<E>): Promise<E>
Asserts that a Trellis RPC-style result is Err and returns the error.
The optional expectation may be an error name string or an error class.
optional
expectedErrorNameOrCtor: string | TrellisTestErrorConstructor<E>
Promise<E>