space-lift/commonjs/union.js

TypeScript Array, Object, Map, Set, Union, Enum utils

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.createUnion = void 0;
/**
 * Creates a type-safe union, providing: derived types, factories and type-guards in a single declaration.
 */
function createUnion(description) {
    const factories = Object.keys(description).reduce((acc, key) => {
        const factory = description[key];
        const factoryWithType = (...args) => (Object.assign({ type: key }, factory.apply(null, args)));
        acc[key] = factoryWithType;
        return acc;
    }, {});
    const isCache = {};
    function is(type) {
        if (isCache[type])
            return isCache[type];
        isCache[type] = (obj) => obj.type === type;
        return isCache[type];
    }
    return Object.assign(Object.assign({}, factories), { is });
}
exports.createUnion = createUnion;