import { describe, expect, it } from "vitest";

import { sumMoney } from "./decimal";

describe("sumMoney", () => {
	it("adds exact signed decimals", () => {
		expect(sumMoney([
			{ currency: "RUB", value: "0.1" },
			{ currency: "RUB", value: "0.2" },
			{ currency: "RUB", value: "-1500000.45" },
			{ currency: "RUB", value: "200" },
		])).toEqual({ currency: "RUB", value: "-1499800.15" });
	});

	it("preserves significant fractional digits and a compensated zero", () => {
		expect(sumMoney([
			{ currency: "RUB", value: "100.5" },
			{ currency: "RUB", value: "49.50" },
			{ currency: "RUB", value: "0.005" },
		])).toEqual({ currency: "RUB", value: "150.005" });
		expect(sumMoney([
			{ currency: "RUB", value: "100" },
			{ currency: "RUB", value: "-100" },
		])).toEqual({ currency: "RUB", value: "0" });
	});

	it.each(["", ".", "1.2.3", "not-a-number"])(
		"rejects malformed amount %s instead of treating it as zero",
		(value) => {
			expect(sumMoney([
				{ currency: "RUB", value: "100" },
				{ currency: "RUB", value },
			])).toBeNull();
		},
	);
});