Make PagingIterator support iterable protocol as well #528
Description
Is your feature request related to a problem? Please describe.
ES2018 supports for-await-of statements, which conveniently iterates over an async iterable object.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for-await...of
PagingIterators returned by enumerating methods of the SDK when config.iterators set to true, however, cannot be directly used in such statements since PagingIterator is just an async iterator, not an async iterable.
const pageit = await client.folders.getItems(folder_id);
for await (const item of pageit) { // won't work
}Describe the solution you'd like
Among several approaches that we may come up with, the simplest one shall be making PagingIterator support the async iterable protocol as well.
It is as simple as adding the following method to PagingIterator class.
[Symbol.asyncIterator]() { return this; }Note: I am not sure this code is compatible with pre-ES2018 runtime which lacks definition for Symbol.asyncIterator.
I am following an idea described in the note in the corresponding MDN article.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols
Describe alternatives you've considered
The suggested solution above has a flaw as the users of an iterable object might expect getting a fresh iterator every time one calls @@asyncIterator method, although it is not mandated by the specification.
It might be more pedantically correct if we had a separate iterable object and making all enumerating SDK methods return it instead of directly returning an iterator, but it is a breaking change.