simple-review-server/src/types.ts

import { object, string, number, InferType } from "yup";

export const reviewSchema = object({
  username: string().strict(true).max(30).required(),
  rating: number().positive().max(5).test(
    "maxDigitsAfterDecimal",
    "Rating can only have at most one integer at half intervals (.0 or .5)",
    number => { !((number! * 10) % 5) }
  ).required(),
  title: string().strict(true).max(50).required(),
  content: string().strict(true).max(2000).notRequired(),
});

export type Review = InferType<typeof reviewSchema>;