TreeView should respond to Space keyboard event

[lukeed]

Description

Because multiple SubTrees can be expanded, it's recommended to allow Space to toggle expansion state.

While there are additional recommended keyboard navigations, these others aren't as common. Using Space seems to be supported everywhere.

Steps to reproduce

1. Visit any TreeView instance; see examples
2. Activate keyboard focus into TreeView
3. Focus a directory item & verify that left/right arrows and Enter are working
4. Press Space –> no toggle

Version

35.29.0 & latest

Browser

Chrome, Safari, Firefox

[siddharthkp]

Hi!

That's a very good bug report, thanks for taking the time!

Because multiple SubTrees can be expanded, it's recommended to allow Space to toggle expansion state.

Luckily, the interactions in TreeView are documented here: https://github.com/github/primer/blob/main/apis/tree-view-api.md#keyboard-interaction

I'll confirm with our accessibility experts if we are missing the control for Space in that spec ^ ❤

[siddharthkp]

Can't transfer issue to github/primer, so going to create a copy: https://github.com/github/primer/issues/3057

Closing the issue here!