Function toObservable

packages/forms/src/validators.ts:609–621

(value: any)

}

export function toObservable(value: any): Observable<any> {
  const obs = isPromise(value) ? from(value) : value;
  if ((typeof ngDevMode === 'undefined' || ngDevMode) && !isSubscribable(obs)) {
    let errorMessage = `Expected async validator to return Promise or Observable.`;
    // A synchronous validator will return object or null.
    if (typeof value === 'object') {
      errorMessage +=
        ' Are you using a synchronous validator where an async validator is expected?';
    }
    throw new RuntimeError(RuntimeErrorCode.WRONG_VALIDATOR_RETURN_TYPE, errorMessage);
  }
  return obs;
}

function mergeErrors(arrayOfErrors: (ValidationErrors | null)[]): ValidationErrors | null {
  let res: {[key: string]: any} = {};