example.test.ts

// exploring vitest behaviour with --pool=forks vs --pool=threads
// spoiler alert: same module, same behaviour - server is only created *once*

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

const server = {
    a: 0
}

describe("some module", () => {
    it.each([
        { foo: 1, bar: 2, sum: 3 },
        { foo: 3, bar: 4, sum: 7 },
    ])(
        "testing with foo=$foo and bar=$bar, sum=$sum",
        async ({ foo, bar, sum }) => {
            server.a += foo + bar
            expect(server.a).toBe(sum)
        })
})

describe("another module", () => {
    it.each([
        { foo: 1, bar: 2, sum: 3 },
        { foo: 3, bar: 4, sum: 7 },
    ])(
        "testing with foo=$foo and bar=$bar, sum=$sum",
        async ({ foo, bar, sum }) => {
            server.a += foo + bar
            expect(server.a).toBe(sum)
        })
})