[Validation] Allow rule only field

[kiaking]

Currently, useV can only define keys that exist in the given data. But there are cases where having virtual field only for validation makes sense. Can we make this possible?

const { data } = useD({
  firstName: '',
  lastName: ''
})

const { validation } = useV(data, {
  // This gives type error right now.
  fullName: {
    require: rule(() => {
      return data.value.firstName && data.value.lastName
    })
  }
})

[brc-dd]

Bit tricky without casting. Maybe just set fullName: undefined in useD call 👀

[kiaking]

Hmmm yeah make sense 👀 Let's go with that 👍