ts-validation-functions

A small validation library primarily targeted at form validation

goals

• Generate a validator based on an existing Type
• Make it as composable as possible
• Infer types whenever possible
• Produce errors that can be used by forms

example

import { mergeValidators, validate, Validators } from "ts-validation-functions";
const { hasProperty, minLength, maxLength, min, max, ifProperty, each } =
  Validators;

type Person = {
  firstname: string;
  lastname: string;
  salutation?: string;
  age: number;
  cars: Car[];
};

type Car = {
  name: string;
  horsepower?: number;
};

const isCar = mergeValidators<Car>(
  hasProperty("name", minLength(1), maxLength(10)),
  ifProperty("horsepower", min(10), max(500))
);

const isName = mergeValidators<string>(minLength(1), maxLength(50));

const isPerson = mergeValidators<Person>(
  hasProperty("firstname", isName),
  hasProperty("lastname", isName),
  ifProperty("salutation", minLength(1), maxLength(10)),
  hasProperty("cars", each(isCar))
);

const errors = validate(
  {
    firstname: "John",
    lastname: "Doe",
    salutation: "Mr",
    age: 10,
    cars: [
      {
        name: "Ferrari",
      },
      {
        name: "Ford",
        horsepower: 100,
      },
    ],
  },
  isPerson
);

license

MIT