Add IAsyncEnumerable pagination support (#58)

[daviburg]

Summary

Implements IAsyncEnumerable<T> auto-pagination for paginated connector operations, following the Azure SDK pagination standard.

Closes #58

Breaking Changes

This is a pre-release breaking change (no customer previews shipped yet):

Method	Before	After
OnedriveforbusinessClient.ListFolderAsync	Task<BlobMetadataPage>	ConnectorPageable<BlobMetadataPage, BlobMetadata>
TeamsClient.GetMessagesFromChannelAsync	Task<GetMessagesFromConversationResponse>	ConnectorPageable<GetMessagesFromConversationResponse, ChatMessage>
TeamsClient.GetMessagesFromChatAsync	Task<GetMessagesFromConversationResponse>	ConnectorPageable<GetMessagesFromConversationResponse, ChatMessage>

What Changed

New Infrastructure

• IPageable<T> — Interface for page types with Value + NextLink
• ConnectorPageable<TPage, TItem> — IAsyncEnumerable<TItem> that follows NextLink automatically, with AsPages() for page-level access

Paginated Methods (Breaking)

• ListFolderAsync, GetMessagesFromChannelAsync, GetMessagesFromChatAsync now return ConnectorPageable instead of Task<Page>

Bug Fix (All Connectors)

• CallConnectorAsync in all 6 connectors now supports absolute NextLink URLs via Uri.IsWellFormedUriString — previously would incorrectly prepend connectionRuntimeUrl to absolute URLs

Tests

• 8 tests for ConnectorPageable (empty/null pages, single/multi-page, AsPages, cancellation, constructor validation)
• 4 tests for OneDrive pagination (single-page, multi-page, AsPages, absolute URL verification)

Usage

// Automatic item-level iteration (no NextLink handling needed)
await foreach (var file in client.ListFolderAsync("root"))
{
    Console.WriteLine(file.Name);
}

// Page-level access when needed
await foreach (var page in client.ListFolderAsync("root").AsPages())
{
    Console.WriteLine($"Page: {page.Value.Count} items, NextLink={page.NextLink}");
}

Cross-Language Design

This pattern maps directly to all three SDK languages:

• C#: await foreach / IAsyncEnumerable<T>
• Python: async for / __aiter__
• Node/TS: for await...of / Symbol.asyncIterator

Samples

Companion PR in Connectors-NET-Samples will demonstrate the pattern end-to-end.

[daviburg]

Companion samples PR demonstrating the pagination pattern: Azure/Connectors-NET-Samples#25

[Copilot]

Pull request overview

Adds SDK-wide async pagination support so generated connector operations can be consumed via await foreach, aligning with Azure SDK pagination patterns and enabling automatic nextLink traversal.

Changes:

• Introduces IPageable<T> and ConnectorPageable<TPage, TItem> to support item- and page-level async iteration over paginated connector responses.
• Updates select generated connector operations to return ConnectorPageable instead of Task<Page> and wires up nextLink traversal.
• Updates generated CallConnectorAsync URL construction to accept absolute nextLink URLs and adds unit tests covering pagination behavior.

Reviewed changes

Copilot reviewed 4 out of 10 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
tests/Microsoft.Azure.Connectors.Sdk.Tests/OnedriveforbusinessClientTests.cs	Adds OneDrive folder listing pagination tests (single/multi-page, AsPages(), absolute nextLink behavior).
tests/Microsoft.Azure.Connectors.Sdk.Tests/ConnectorPageableTests.cs	New unit tests for ConnectorPageable enumeration semantics, constructor validation, and cancellation token propagation.
src/Microsoft.Azure.Connectors.Sdk/IPageable.cs	Adds a public interface describing a paginated page shape (Value + NextLink).
src/Microsoft.Azure.Connectors.Sdk/ConnectorPageable.cs	Adds IAsyncEnumerable<T> implementation that auto-follows NextLink, plus AsPages() for page-level iteration.
src/Microsoft.Azure.Connectors.Sdk/Generated/TeamsExtensions.cs	Makes messages list response pageable and updates message listing methods to return ConnectorPageable; adjusts URL building for absolute paths.
src/Microsoft.Azure.Connectors.Sdk/Generated/SharepointonlineExtensions.cs	Updates URL building to support absolute paths/nextLinks.
src/Microsoft.Azure.Connectors.Sdk/Generated/OnedriveforbusinessExtensions.cs	Makes folder listing response pageable, changes ListFolderAsync to return ConnectorPageable, and updates URL building for absolute paths/nextLinks.
src/Microsoft.Azure.Connectors.Sdk/Generated/Office365Extensions.cs	Updates URL building to support absolute paths/nextLinks.
src/Microsoft.Azure.Connectors.Sdk/Generated/MsgraphgroupsanduserExtensions.cs	Updates URL building to support absolute paths/nextLinks.
src/Microsoft.Azure.Connectors.Sdk/Generated/KustoExtensions.cs	Updates URL building to support absolute paths/nextLinks.

[daviburg]

Companion BPM generator PR: AzureUX-BPM#15561655. Generated code now regenerated from the updated generator — pagination types, ConnectorPageable returns, ResolveUrl with SSRF host validation, and ManagedIdentityCredential fix all included.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 10 changed files in this pull request and generated 12 comments.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 10 changed files in this pull request and generated 7 comments.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 10 changed files in this pull request and generated 1 comment.