JsonSerializer no longer passes the CancellationToken to the AsyncEnumerable

[Tratcher]

Description

This commit refactored the JsonSerializer:
3559d33#diff-65021de09c4fb9b39607f1f3ed228e53cd04b483880f66b0ea56310f71a5e400L320

However, now state.CancellationToken doesn't get set anymore. This is failing tests in AspNetCore
https://dev.azure.com/dnceng-public/public/_build/results?buildId=109479&view=ms.vss-test-web.build-test-results-tab&runId=2337376&resultId=105425&paneView=debug

runtime/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Metadata/JsonTypeInfoOfT.WriteHelpers.cs

Lines 117 to 122 in 0e60130

	WriteStack state = default;
	state.Initialize(this,
	rootValueBoxed,
	isInvokedByPolymorphicConverter,
	supportContinuation: true,
	supportAsync: true);

Reproduction Steps

The test cancels the token as soon as the async enumeration starts, but the token is not passed through to the IAsyncEnumerable.
https://github.com/dotnet/aspnetcore/blob/6956f42a0a01ed4fb8fc2cb889c2535f8fe5f735/src/Http/Http.Extensions/test/HttpResponseJsonExtensionsTests.cs#L360-L369

Expected behavior

The cancellation token should be passed through to the enumerator.

Actual behavior

The cancellation token is not passed through to the enumerator.

Regression?

Yes, 7 days ago.
3559d33#r92837773

Known Workarounds

No response

Configuration

8.0.0-alpha.1.22611.2
https://github.com/dotnet/aspnetcore/pull/45475/files#diff-1ea18ff65faa2ae6fed570b83747086d0317f5e4bc325064f6c14319a9c4ff67R122

Other information

No response

Tagging subscribers to this area: @dotnet/area-system-text-json, @gregsdennis
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Issue Details

---

Description

This commit refactored the JsonSerializer:
3559d33#diff-65021de09c4fb9b39607f1f3ed228e53cd04b483880f66b0ea56310f71a5e400L320

However, now state.CancellationToken doesn't get set anymore. This is failing tests in AspNetCore
https://dev.azure.com/dnceng-public/public/_build/results?buildId=109479&view=ms.vss-test-web.build-test-results-tab&runId=2337376&resultId=105425&paneView=debug

runtime/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Metadata/JsonTypeInfoOfT.WriteHelpers.cs

Lines 117 to 122 in 0e60130

	WriteStack state = default;
	state.Initialize(this,
	rootValueBoxed,
	isInvokedByPolymorphicConverter,
	supportContinuation: true,
	supportAsync: true);

Reproduction Steps

The test cancels the token as soon as the async enumeration starts, but the token is not passed through to the IAsyncEnumerable.
https://github.com/dotnet/aspnetcore/blob/6956f42a0a01ed4fb8fc2cb889c2535f8fe5f735/src/Http/Http.Extensions/test/HttpResponseJsonExtensionsTests.cs#L360-L369

Expected behavior

The cancellation token should be passed through to the enumerator.

Actual behavior

The cancellation token is not passed through to the enumerator.

Regression?

Yes, 7 days ago.
3559d33#r92837773

Known Workarounds

No response

Configuration

8.0.0-alpha.1.22611.2
https://github.com/dotnet/aspnetcore/pull/45475/files#diff-1ea18ff65faa2ae6fed570b83747086d0317f5e4bc325064f6c14319a9c4ff67R122

Other information

No response

Author:	Tratcher
Assignees:	-
Labels:	area-System.Text.Json
Milestone:	-

[eiriktsarpalis]

Our test coverage seems to have missed that because it relied on validating that the serialization operation throws TaskCanceledException:

runtime/src/libraries/System.Text.Json/tests/Common/CollectionTests/CollectionTests.AsyncEnumerable.cs

Lines 129 to 141 in fdd1f63

	var longRunningEnumerable = new MockedAsyncEnumerable<int>(
	source: Enumerable.Range(1, 1000),
	delayInterval: 1,
	delay: TimeSpan.FromMilliseconds(enumeratorDelayMilliseconds),
	passCancellationTokenToDelayTask);
	using var utf8Stream = new Utf8MemoryStream();
	using var cts = new CancellationTokenSource(delay: TimeSpan.FromMilliseconds(cancellationTokenSourceDelayMilliseconds));
	await Assert.ThrowsAsync<TaskCanceledException>(async () =>
	await JsonSerializer.SerializeAsync(utf8Stream, longRunningEnumerable, cancellationToken: cts.Token));
	Assert.Equal(1, longRunningEnumerable.TotalCreatedEnumerators);
	Assert.Equal(1, longRunningEnumerable.TotalDisposedEnumerators);

Looking at your test, is it fair to assume that your destination stream is ignoring cancelled tokens?

[Tratcher]

The destination stream is MemoryStream, which should honor cancellation.

[eiriktsarpalis]

Even though the token is not passed to the converters, it is still being passed to the underlying stream so I would expect this line

https://github.com/dotnet/aspnetcore/blob/6956f42a0a01ed4fb8fc2cb889c2535f8fe5f735/src/Http/Http.Extensions/test/HttpResponseJsonExtensionsTests.cs#L350

to throw TaskCanceledException.