simple-review-server/src/types.ts

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

export const reviewSchema = object({
  username: string().required(),
  rating: number().positive().max(5).test(
    "maxDigitsAfterDecimal",
    "Rating must have at most 1 decimal place",
    number => Number.isInteger(number! * 10)
  ).required(),
  content: string(),
});

export type Review = InferType<typeof reviewSchema>;