Handle optional values safely

Always provide safe defaults or fallbacks when working with optional or potentially undefined values. Avoid using non-null assertion operators (!) on optional parameters, and ensure proper handling in type checking and value merging scenarios.

Key practices:

• Use default objects instead of non-null assertions: val(info || { props: {} }) instead of val(info!)
• Order type checks to handle undefined cases first: check for object & not null, then boolean, then provide defaults
• Provide fallbacks for missing values: color: var(--ant-tooltip-color, ${tooltipColor}) instead of assuming the CSS variable exists
• Skip undefined values in object merging to preserve existing values rather than overwriting with undefined

Example:

// ❌ Dangerous - assumes info exists
return val(info!) as T;

// ✅ Safe - provides default
return val(info || { props: {} as Props }) as T;

// ❌ No fallback for missing CSS variable  
color: 'var(--ant-tooltip-color)',

// ✅ Provides fallback
color: `var(--ant-tooltip-color, ${tooltipColor})`,

This prevents runtime errors and ensures predictable behavior when dealing with optional or missing values.