@jguyon/check is a library of simple composable functions that you can use
together to validate data.
npm install --save @jguyon/checkYou create a validation function by composing smaller validation functions created by the utilities provided by this library.
For example:
import * as check from "@jguyon/check";
const checkName = check.chain(
check.string(),
check.trim(),
check.minLength(2),
check.maxLength(24),
);
checkName(" Jérôme ");
// => { isOk: true, value: "Jérôme" }
checkName("J");
// => { isOk: false, error: "is too short", ... }The validation functions that this library composes are simple functions that take the value to validate and return a valid or invalid result, so you can easily write your own:
import * as check from "@jguyon/check";
const checkLink = check.chain(check.string(), check.trim(), (value) =>
value.startsWith("https://")
? check.ok(value)
: check.error(value, "is not a secure link"),
);
checkLink(" https://example.com ");
// => { isOk: true, value: "https://example.com" }
checkLink("http://example.com");
// => { isOk: false, error: "is not a secure link", ... }Additional arguments passed to the validation function are passed to the child validation functions:
import * as check from "@jguyon/check";
const checkPasswordConfirmation = check.chain(
check.string(),
(value, password) =>
value === password
? check.ok(value)
: check.error(value, "does not match password"),
);
checkPasswordConfirmation("password", "password");
// => { isOk: true, value: "password" }
checkPasswordConfirmation("invalid", "password");
// => { isOk: false, error: "does not match password", ... }Here is the full documentation.