code-block.tsx: TokensResult fg/bg are optional in Shiki types, but TokenizedCode requires string (strictNullChecks error)

[t-koyoyo]

Summary

In packages/elements/src/code-block.tsx, TokenizedCode defines fg/bg as required string, but codeToTokens returns TokensResult where fg/bg are optional (string | undefined). With strictNullChecks: true, this triggers a type error.

Steps to Reproduce

1. Use packages/elements/src/code-block.tsx as-is.
2. Enable strictNullChecks (or strict: true) in TS config.
3. Type check the project.

Expected

No TypeScript error.

Actual

Type error:
Type 'string | undefined' is not assignable to type 'string'.

References

• code-block.tsx: const tokenized: TokenizedCode = { tokens: result.tokens, fg: result.fg, bg: result.bg }
  
  
• Shiki types: TokensResult.fg? / bg? are optional.
  

Possible Fixes

• Make TokenizedCode use string | undefined for fg/bg
• Or provide defaults (fg: result.fg ?? "inherit", bg: result.bg ?? "transparent")
• Or use non-null assertion if intended

Environment

• TypeScript: (e.g.) 5.x
• Shiki: 3.21.0
• strictNullChecks: true