Type-A supports complex composite types through a family of descriptors:
t.tuple(A, B, C) – fixed-length, positional arrays.t.union(A, B) – compile-time union with runtime discriminator.t.variant({ kind: T.literal("a"), ... }) – tagged unions (a.k.a. algebraic variants).import { describe, it, expect } from "vitest";
import { Schema, one, typed as t } from "@rybosome/type-a";
describe("Tuple and union fields", () => {
it("accepts a tuple and a strict union", () => {
class CoordX extends Schema.from({ x: one(t.number) }) {}
class CoordY extends Schema.from({ y: one(t.number) }) {}
class Shape extends Schema.from({
point: one(t.tuple(t.number, t.number)),
coord: one(t.union([CoordX, CoordY])),
}) {}
const s = new Shape({ point: [1, 2], coord: { x: 1 } });
expect(s.coord).toBeInstanceOf(CoordX);
});
});
The variant helper builds on top of union and is covered in nested schemas.