The Built-In Transformations

Derive rather than duplicate. A near-copy of a type will eventually disagree with the original, in exactly the way a repeated author name disagrees in the SQL course. The utility types are how you avoid the copy.

The last line is rejected because BookDraft has no id. Add a field to Book and all three derived types follow automatically.

The ones worth knowing.

Partial<T> every property optional, for updates.

Required<T> the opposite.

Readonly<T> every property readonly.

Pick<T, K> only those properties.

Omit<T, K> all but those.

Record<K, V> an object with those keys and values.

ReturnType<typeof fn> whatever a function returns.

That is most of what you will use. The rest can wait until you meet them.