Vue js vuelidate cannot create Dynamic validation schema

Question

I need t o create Dynamic validation schema with many checks, because date could have different parameters.

i tried to do something like this

validations() {
        if (this.NewItem.type === 3) {
            return {
                NewItem: {
                    abp: { required },             
                      bp: {},
                        ppr: { },
                      name_ru: {required},

                }
            };
        }
         else if (this.NewItem.type === 4)
         {
        return {
            NewItem: {
                abp: {},
                 bp: {required},
                   ppr: {  },
                name_ru: { required }
            }
        };}
         else if (this.NewItem.type === 5)
         {
        return {
            NewItem: {
                abp: {},
                bp: { },
                 ppr: { required },
                name_ru: { required }
            }
        };}
    },

it's not working.

**Only works this way **

validations() {
    if (!this.hasDescription) {
      return {
        name: {
          required
        }
      }
    } else {
      return {
        name: {
          required
        },
        description: {
          required
        }
      }
    }
  }
}

but i need more more options