shelving/schema/Schema.js

Toolkit for using data in JavaScript.

import { PASSTHROUGH } from "../util/function.js";
import { getNull } from "../util/null.js";
import { getUndefined } from "../util/undefined.js";
/**
 * Schema is an object instance with a `validate()` method.
 * - Type `T` represents the type of value `validate()` returns.
 * - `validate()` returns `Invalid` if value was not valid.
 */
export class Schema {
    /** String for one of this thing, e.g. `product` or `item` or `sheep` */
    one;
    /** String for several of this thing, e.g. `products` or `items` or `sheep` (defaults to `one` + "s") */
    many;
    /** Title of the schema, e.g. for using as the title of a corresponding field. */
    title;
    /** Description of the schema, e.g. for using as a description in a corresponding field. */
    description;
    /** Placeholder of the schema, e.g. for using as a placeholder in a corresponding field. */
    placeholder;
    /** Default value for the schema if `validate()` is called with an `undefined` value. */
    value;
    constructor({ one = "value", many = `${one}s`, title = "", description = "", placeholder = "", value }) {
        this.one = one;
        this.many = many;
        this.title = title;
        this.description = description;
        this.placeholder = placeholder;
        this.value = value;
    }
}
// Unknown validator always passes through its input value as `unknown`
export const UNKNOWN = {
    one: "none",
    many: "none",
    title: "",
    description: "",
    placeholder: "",
    value: undefined,
    validate: PASSTHROUGH,
};
// Undefined validator always returns `undefined`
export const UNDEFINED = { ...UNKNOWN, validate: getUndefined };
// Null validator always returns `null`
export const NULL = { ...UNKNOWN, validate: getNull };