Article posting

[sgg]

Add the ability to post articles. Now would probably be a good time to introduce some integration tests!

POST is particularly tricky because (like IHAVE) it is a two stage command. If we model this incorrectly we could end up with an inconsistent stream state. The workflow is as follows:

1. Client sends POST
2. Server replies with status
3. If status is 340, send post and check response. Otherwise stop.

• Implement POST command(s)
• Provide builder(s)
• Provide first class support in the NntpClient so that users do not have to deal with the stateful nature themselves
• Provide doc examples and worked example

[sgg]

I've elected to model POST as two NntpCommands -- InitiatePost and Post.

InitiatePost can be used to initiate transfers and Post can be used to transfer an actual article. There is a Builder provided for creating these from headers and a body.

Fundamentally article transfer looks like two command/response exchanges, so I chose to model it that way.
This is line w/ Brokaw's general design philosophy -> leave the low level bits simple and introducing more user friendly abstractions at the NntpClient layer.

Alternatives Considered

1. Modifying the NntpCommand to support stateful behavior. I decided against as very few commands have this kind of behavior (w/r/t RFC3977 it's just POST and IHAVE). The added complexity that would be required here does not seem to be worth it.
2. Introducing new traits/types that can represent command sequences. Again, more code, more complexity, little benefit.

---

I am still chewing on the UX. I will definitely introduce a method in the NntpClient to make article transfer easier. A higher level Article may also be introduced.

Users may want:

• Creating articles from streams (aka a file/buffer)
• mandatory header validation.

[r3k2]

Hello @sgg so post is working? I am about to start a TUI usenet client and thinking in using this libraries...