Cody Context: Better usage of editor selection and UI update

[umpox]

Description

This PR improves how Cody uses the current editor selection and displays it is part of the UI.

UI Changes:

We now display the selected lines against the file in the context footer. I went with start.line-end.line but happy to tweak if others feel a better UI would work.

Alternatives I considered:

• start.line:start.character-end.line:end.character (feels too noisy/verbose)
• L(start.line)-L(end.line)

Prompt changes:

We have always included the editor selection if present, but now we include it as the last piece of context. Cody uses it a lot more consistently now. I think this makes sense: broad context (embeddings) -> file context (editor contents) -> selection context (selection contents).

Example improvement:

BEFORE	AFTER

Test plan

Tested various prompts with different editor selections.

[toolmantim]

Love it!! Great work on making it feel so responsive too.

Looks like you might have an off-by-one error on the line number though:

Screen.Recording.2023-06-20.at.8.57.58.pm.mov

[umpox]

@toolmantim Thanks for testing, have just fixed that now! (think we caught it at the same time :D)

[toolmantim]

Working well for me! 👍🏼 from the UI & design side of things.

I do have a question though…

What's the difference between having my cursor on a line:

and selecting the line:

I would have naively assumed it would be the same thing. But do they affect the results you get?

If this design makes sense though, I'm pondering if a tooltip on the context item could help them master using Cody… something like, "The whole of ${file}" and "Lines ${a}-${b} of ${file}" (or "Lines ${a}-${b} of ${file}, and some surrounding lines" if that's the case)

[sourcegraph-bot]

📖 Storybook live preview

[philipp-spiess]

NICE

[umpox]

@toolmantim Good question!

Right now, we only provide Cody context when a user has explicitly selected some text. Having your cursor on a line, or over a variable doesn't have any effect right now.

We could extend this to always use the current cursor position but I think that might be a bit too much. The cursor is almost always going to be somewhere, so we might over index on using that as useful context. I think the correct approach will be to use code intelligence to include the cursor position when it is on a useful symbol (e.g. a variable). This should be possible in the future, I believe #team-cody-context is working on improving this, but will check