707 refactor of chatgptchatcompletion

[pmarsh-scottlogic]

Description

REFACTOR: moves the logic for setting the system role in chat history to its own method (setSystemRoleInChatHistory), and then instead of calling that method from chatGptChatCompletion (openAI module), we call it from handleChatToGPT (chatController module). The idea of moving where it's invoked is to make methods responsible for fewer things.

Rewrites tests accordingly.

Notes

• we also alter the logic to reduce mutation. Except we change the value of the chat history in the session once we've made the updated value (with the system role set)
• unit tests the new method setSystemRoleInChatHistory on its own, then just checks that it gets called in handleChatToGPT
• removes the old integration test that checked setting system roles in the chat history

Concerns

• Wasn't sure where to put the definition of setSystemRoleInChatHistory, so I left it in openai. In my ideal word, we'd have some module "chatService" which sits in between the chatController and the lower level modules (openai, langchain) which would deal with this sort of thing.

Checklist

Have you done the following?

• [x] Linked the relevant Issue
• [x] Added tests
• [x] Ensured the workflow steps are passing

[pmarsh-scottlogic]

Very nice! The only thing I'd prefer would be to move setSystemRoleInChatHistory out of openai.ts. I'd argue it can go in the chat controller, as that's the only place that uses it, although I appreciate that file is getting a little large. Adding services for each controller would be nice, but a little overkill for this ticket. Could be worth making a new issue for it though? 👀 Alternatively, in #740 I added a chat utils file, could go there?

Re chat Service, I've just made #761 to introduce that. I don't think the other controllers are big enough to warrant a service however.

I reckon I'll wait for #740 and put setSystemRoleInChatHistory in there. Thus, consider this PR BLOCKED by #740