mapDefer

Choose a member-mapping function at runtime from the current source object.

mapDefer() returns another member function after inspecting the source:

forMember(
  (destination) => destination.profile,
  mapDefer((source) => {
    if (source.profile.type === 'business') {
      return mapWith(ProfileDto, BusinessProfile, (value) => value.profile);
    }

    return mapWith(ProfileDto, Profile, (value) => value.profile);
  }),
);

Register every nested mapping that the deferred branch can select. Prefer condition() or a direct mapFrom() when only the value changes and the mapping strategy does not.