Variantsinterface

Dictionary of boolean variant flags whose true-valued keys become class names.

• true or false item values in dictionaries use the string key of the item if the value is true, or ignore it if the value is falsy.
• Anything that is not true has no effect, so other values can be passed in and will be ignored. This means you can pass the entire props into this and it'll work just fine.

Typed as object (not Data/Record<string, unknown>) so plain interface types are accepted —
interfaces lack an implicit string index signature, so they don't satisfy index-signature types.