Writing Asynchronous Dart Code

Contents

• Core Guidelines
• Handling Futures
• Managing Streams
• Workflows
• Examples
• Related Skills

Core Guidelines

Write asynchronous Dart code using modern, declarative patterns. Avoid legacy callback-based approaches. Assume all network, file I/O, and database operations are asynchronous.

• Use async/await: Always prefer async and await over raw .then(), .catchError(), or .whenComplete() chains. This flattens the execution flow and improves readability.
• Handle Errors Gracefully: Wrap all await calls in try-catch blocks to handle exceptions. Do not rely on unhandled future rejections.
• Execute Concurrently: Use Future.wait to initiate and await multiple independent futures concurrently rather than awaiting them sequentially.
• Consume Streams Sequentially: Prefer await for over .forEach() or .listen() when consuming streams, unless you specifically need low-level subscription management (like pausing or resuming).
• Prevent Memory Leaks: Always call .close() on a StreamController when it is no longer needed or when the owning class is disposed.