Explicit resource management (using keyword) for Node API

[bestbeforetoday]

As an Node application developer
I want to use explicit resource management (using keyword)
So that I don't need to write clean-up code using try/finally blocks to ensure resources are closed after use

TypeScript 5.2 adds support for the using keyword, defined by the upcoming Explicit Resource Management ECMAScript feature. For closeable resources that are only used within a defined scope, this avoids the need for clean-up code (typically implemented using try/finally blocks to ensure it is called in the event of an error) to close resources. It provides similar capability to Java's try-with-resources, and (to some extent) Go's defer.

This feature proposes that all objects in the Node API with close() methods to perform resource clean-up are augmented to implement the Disposable type, and have a [Symbol.dispose] method that calls the existing close().

For example, the existing application code:

const events = await network.getChaincodeEvents(chaincodeName, { startBlock: BigInt(101) });
try {
    for async (const event of events) {
        // Process event
    }
} finally {
    events.close();
}

Could be simplified to the following, with the close() automatically called when the events variable goes out of scope:

using events = await network.getChaincodeEvents(chaincodeName, { startBlock: BigInt(101) });
for async (const event of events) {
    // Process event
}

Tasks:

• Augment CloseableAsyncIterable
  • Chaincode events
  • Block events
  • Filtered block events
  • Block and private data events
• Augment Gateway
• Add new code examples to API documentation:
  • Network
  • Network#getChaincodeEvents
  • Network#getBlockEvents
  • Network#getFilteredBlockEvents
  • Network#getBlockAndPrivateDataEvents
  • ChaincodeEventsRequest#getEvents
  • BlockEventsRequest#getEvents
  • FilteredBlockEventsRequest#getEvents
  • BlockAndPrivateDataEventsRequest#getEvents

The following samples should also be updated once this capability is published:

• asset-transfer-events
• off_chain_data