import { describe, test, expect } from "vitest"; import { groupBy } from "./groupBy.js"; const list = [ { name: "foo", id: 1 }, { name: "blue", id: 2 }, { name: "foo", id: 3 }, ]; describe("groupBy", () => { test("groupBy", async () => { const result = groupBy(list, (item) => item.name); expect(Object.keys(result).length).toBe(2); expect(result["foo"].length).toBe(2); expect(result["blue"].length).toBe(1); }); });