Should the theme prop be required for non-root components?

[envex]

I noticed that there's a few instances in the repo where the theme prop isn't being correctly passed down to child components. This means that the Default theme is always being used.

Half the problem here is that theme is optional because useTheme uses the Default theme if the theme prop is omitted. We don't get warned if the prop isn't passed down.

My idea is that we:

• Keep theme optional for root chart components (BarChart, LineChart, etc).
• Use theme = 'Default' in those root components to set the default theme.
• Make theme required for any child component that uses it.

[krystalcampioni]

Sounds like a good solution. I'm down for it 🙌🏽

[LBWright]

@krystalcampioni's comment++

[envex]

#1111