Function customFn

test/unit/model/validation.test.js:455–461

(val, next)

        type: Sequelize.INTEGER,
        validate: {
          customFn(val, next) {
            if (val < 0) {
              next('age must be greater or equal zero');
            } else {
              next();
            }
          }
        }
      },
      name: Sequelize.STRING