Adds Disposal Logic for IJSStreamReference in PullFromJSDataStream

[eugeneogongo]

Adds Disposal Logic for IJSStreamReference in PullFromJSDataStream

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Refactor PullFromJSDataStream disposal logic and add Dispose unit tests

Description

{Detail}

Fixes #62140 (in this specific format)

[dotnet-policy-service]

Thanks for your PR, @@eugeneogongo. Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[Copilot]

Pull Request Overview

This PR adds disposal logic for IJSStreamReference in PullFromJSDataStream and introduces unit tests to verify the disposal behavior. The changes refactor the stream to use a CancellationTokenSource instead of a CancellationToken directly, and implement both synchronous and asynchronous disposal patterns.

• Replaces direct CancellationToken usage with CancellationTokenSource for better lifecycle management
• Adds Dispose(bool disposing) and DisposeAsync() override methods to properly clean up resources
• Introduces unit tests to verify that disposal calls propagate to the underlying IJSStreamReference

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 5 comments.

File	Description
src/Components/Shared/src/PullFromJSDataStream.cs	Implements disposal pattern with CancellationTokenSource management and IJSStreamReference cleanup
src/Components/WebAssembly/WebAssembly/test/PullFromJSDataStreamTest.cs	Adds unit tests for synchronous and asynchronous disposal behavior, removes unused import

[Copilot]

The Preserve() extension method does not exist in the codebase. This will cause a compilation error.

To properly handle the fire-and-forget disposal in a synchronous context, you should use .AsTask() or simply discard the ValueTask without calling any method on it. Consider one of these alternatives:

// Option 1: Just discard the ValueTask (allows it to be collected)
_ = _jsStreamReference?.DisposeAsync();

or if you need to ensure the task runs:

// Option 2: Convert to Task (ensures the task runs)
_ = _jsStreamReference?.DisposeAsync().AsTask();

Suggested change

	_ = _jsStreamReference?.DisposeAsync().Preserve();
	_ = _jsStreamReference?.DisposeAsync();

[Copilot]

The _streamCts CancellationTokenSource is never disposed, which can lead to resource leaks. You should dispose it in both Dispose and DisposeAsync methods.

Add disposal after cancellation:

_streamCts?.Cancel();
_streamCts?.Dispose();