Update task-id and context-id when a non final status-update arrives

[graemefoster]

Description

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Fixes #119

[holtskinner]

Thanks for your contribution! However, this sample is being replaced here: https://github.com/google-a2a/a2a-js/blob/main/src/samples/cli.ts

@swapydapy Can review what you have.

[swapydapy]

The check for currentTaskId and current ContextId is already there when task object is first streamed.
https://github.com/a2aproject/a2a-js/blob/main/src/samples/cli.ts#L304

An Agent is supposed to first send a Task object, and then subsequent task updates.

[graemefoster]

@swapydapy is that documented somewhere? I haven’t looked for a while but felt like the semantics of the protocol are not that obvious - what is sent and when, that sort of thing.

That the message updates contain a task id led me to believe that this was acceptable.

Iirc the examples also don’t (didn’t) make this clear.

[graemefoster]

@swapydapy see here: https://a2aproject.github.io/A2A/latest/specification/#71-messagesend

no mention that the first message must be a task.