Add SentTimestamp to SQSMetadata

[burhansavci]

#283

Adds the SentTimestamp message system attribute to the SQSMetadata class and maps it in the MessageMetadataHandler.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[JanHyka]

Why is the 'long' timestamp a string? Is it stored in the json itself as a quoted string? Even if so, is there any possibility to have non-numerical value?

[burhansavci]

I kept it as a string? for three main reasons:

• The AWS SQS API itself returns this value as a string within the JSON payload, as documented in here.
• The underlying data structure for all SQS message attributes is a Dictionary<string, string>, so it's read as a string by default.
• I'm accustomed to converting this into a long myself, then into DateTimeOffset if needed, when I directly use the Message class. It might be best to maintain the same behavior.

However, I agree that converting it to a long in the SQSMetadata class is more appropriate, as there's no indication in the documents that it could be anything else. I can update my PR if that's fine.

[JanHyka]

I am not one to decide, I just stumbled on that since it looks quite suspicious :-)
(and I might have to propagate it correctly in my serializers PR if your goes first, hence the questions)

[burhansavci]

Got it.😄 In that case, let's wait for the team's decision.

[GarrettBeatty]

@normj any preference on which one makes more sense?

[normj]

Thanks for the PR. I do agree this is a useful to add.

For the better user experience I think this library should do the conversion to DateTime from the epoch. It is only a string in the SDK because the timestamp is being given in the generic message attribute class. One of the goals of this library is to make the experience working with SQS more .NET idiomatic then the generated SQS client.

[burhansavci]

@normj, any particular reason for DateTime instead of DateTimeOffset here?

[Copilot]

Pull Request Overview

This PR adds SentTimestamp support to the SQS metadata handling functionality by exposing the SQS message system attribute for timestamp information.

• Adds SentTimestamp property to the SQSMetadata class
• Maps the SentTimestamp attribute in the message metadata handler
• Updates version tracking for the AWS.Messaging package

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/AWS.Messaging/SQSMetadata.cs	Adds SentTimestamp property with documentation
src/AWS.Messaging/Serialization/Handlers/MessageMetadataHandler.cs	Maps SentTimestamp attribute from SQS message
.autover/changes/45a6ab22-5bb9-4b65-bfb1-94571b502622.json	Version tracking for the new feature

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}