`overrideTokens` replace theme-wide tokens, instead of cascading

[mischreiber]

Environment Information

• Platform:
  • [x] iOS
  • [ ] macOS
• Package version(s): 0.5.0, all package managers
• Xcode and OS versions: Xcode 13.3.1, iOS 15.x

Please provide a reproduction of the bug:

• Open a demo view that supports both per-control override and theme-wide override tokens (e.g. CardNudge)
• Update theme-wide override to include additional properties beyond what are covered by per-control override tokens (e.g. accentColor)
• Enable theme-wide override, then per-control override.

Actual behavior:

Theme-wide custom accentColor is replaced by default value.

Expected behavior:

Theme-wide custom accentColor is maintained, as per-control override doesn't override that value.

Priorities and help requested:

Are you willing to submit a PR to fix? (Yes, No)

Requested priority: (Blocking, High, Normal, Low)

Products/applications affected: (if applicable)

[mischreiber]

The fix for this will be to implement some form of cascading token resolution. I have a WIP in my personal fork; PR expected in the coming days.

[mischreiber]

This is now fixed in the fluent2-tokens branch. Next step will be merging to main.

[mischreiber]

Resolved back with https://github.com/microsoft/fluentui-apple/pull/1219, which is now released in the 0.8 branch!