[Analyzer] Async methods that don't take a CancellationToken

[stephentoub]

Cancellation is often important to the scalability of an app / service. If an async method has no way to cancel it, that can impact scalability and responsiveness. We should consider adding an analyzer (likely off by default due to noise) that flags async methods (async and/or Task/ValueTask-returning) that have no overloads which accept a CancellationToken, and issue a diagnostic to consider taking one.

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Issue Details

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Cancellation is often important to the scalability of an app / service. If an async method has no way to cancel it, that can impact scalability and responsiveness. We should consider adding an analyzer (likely off by default due to noise) that flags async methods (async and/or Task/ValueTask-returning) that have no overloads which accept a CancellationToken, and issue a diagnostic to consider taking one.

Author:	stephentoub
Assignees:	-
Labels:	area-System.Threading.Tasks, code-analyzer
Milestone:	-

[bartonjs]

Video

Looks good as proposed (finding Task-like returning method groups with no overloads that accept a CancellationToken).

Category: Design
Severity: None (off by default)