example.test.js

const sum = (a, b) => a + b

describe("number adding", () => {
  describe("number summation", () => {
    it("adds 1 + 2 to equal 3", () => {
      expect(sum(1, 2)).toBe(3)
    })
  })
})

describe("server", () => {
  it("should work", () => {})
})