Allow multiple invocations of streaming Lambda functions with the local test server

[sebsto]

The Local HTTP Server (used when testing) used to block after one invocation of a streaming lambda function. Now you can invoke multiple times your streaming function without having to restart the local HTTP server.

Motivation:

Bug #588

Modifications:

The flow to respond to streaming and non-streaming requests are different. In the streaming request flow, we forgot to send an 202 accept response to the lambda runtime client after it posted the end chunck of the response (in other words, POST /response never received an HTTP 202 response.) This caused the Lambda Runtime to hang and never issue the next GET /next request.

Result:

You can now send multiple invocations to your streaming lambda.

[Copilot]

Pull Request Overview

This PR fixes a bug in the local test server that prevented multiple invocations of streaming Lambda functions. The issue was that streaming responses weren't receiving the required HTTP 202 acknowledgment after posting the end chunk, causing the Lambda runtime to hang instead of processing the next request.

Key Changes:

• Added missing HTTP 202 response acknowledgment for streaming function end chunks
• Added comprehensive test coverage for streaming Lambda functions including multiple invocations, custom headers, and error handling

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
Sources/AWSLambdaRuntime/Lambda+LocalServer.swift	Added HTTP 202 acknowledgment response for streaming END chunks to allow runtime to continue processing
Tests/AWSLambdaRuntimeTests/LambdaStreamingTests.swift	Added comprehensive test suite covering streaming handlers with multiple invocations, custom headers, and error scenarios

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[Copilot]

Pull Request Overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.

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[adam-fowler]

Looks good