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plugins/csharp-dotnet-development/commands/csharp-async.md

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+---
+agent: 'agent'
+tools: ['changes', 'search/codebase', 'edit/editFiles', 'problems']
+description: 'Get best practices for C# async programming'
+---
+
+# C# Async Programming Best Practices
+
+Your goal is to help me follow best practices for asynchronous programming in C#.
+
+## Naming Conventions
+
+- Use the 'Async' suffix for all async methods
+- Match method names with their synchronous counterparts when applicable (e.g., `GetDataAsync()` for `GetData()`)
+
+## Return Types
+
+- Return `Task<T>` when the method returns a value
+- Return `Task` when the method doesn't return a value
+- Consider `ValueTask<T>` for high-performance scenarios to reduce allocations
+- Avoid returning `void` for async methods except for event handlers
+
+## Exception Handling
+
+- Use try/catch blocks around await expressions
+- Avoid swallowing exceptions in async methods
+- Use `ConfigureAwait(false)` when appropriate to prevent deadlocks in library code
+- Propagate exceptions with `Task.FromException()` instead of throwing in async Task returning methods
+
+## Performance
+
+- Use `Task.WhenAll()` for parallel execution of multiple tasks
+- Use `Task.WhenAny()` for implementing timeouts or taking the first completed task
+- Avoid unnecessary async/await when simply passing through task results
+- Consider cancellation tokens for long-running operations
+
+## Common Pitfalls
+
+- Never use `.Wait()`, `.Result`, or `.GetAwaiter().GetResult()` in async code
+- Avoid mixing blocking and async code
+- Don't create async void methods (except for event handlers)
+- Always await Task-returning methods
+
+## Implementation Patterns
+
+- Implement the async command pattern for long-running operations
+- Use async streams (IAsyncEnumerable<T>) for processing sequences asynchronously
+- Consider the task-based asynchronous pattern (TAP) for public APIs
+
+When reviewing my C# code, identify these issues and suggest improvements that follow these best practices.