/** * Creates the TypeError to throw if an invalid object is passed to `from` or `scheduled`. * @param input The object that was passed. */ export function createInvalidObservableTypeError(input: any) { // TODO: We should create error codes that can be looked up, so this can be less verbose. return new TypeError( `You provided ${ input !== null && typeof input === 'object' ? 'an invalid object' : `'${input}'` } where a stream was expected. You can provide an Observable, Promise, ReadableStream, Array, AsyncIterable, or Iterable.` ); }