optimized test case in part of Given

basic-short-given-test-case.ts

import { updateUser } from "./userService"
import { createUser } from "../tests/helpers/createUser"

describe('UserService - updateUser', () => {
    it('should update department', () => {
        // GIVEN
        const user = createUser()
        const updateData = {
            department: 'IT Support',
        }
        // WHEN
        const currentUser = updateUser(user, updateData)

        // THEN
        expect(currentUser).toStrictEqual({
            id: 'e2f5a82a-3f2e-4b6d-b4d2-086afaa08f8a',
            username: 'john',
            email: '[email protected]',
            country: 'France',
            department: 'IT Support',
            divisionName: 'IT',
        })
    })
})

createUser.ts

import { User } from "../../src/userService"

export const createUser = (data: Partial<User> = {}) => ({
    id: 'e2f5a82a-3f2e-4b6d-b4d2-086afaa08f8a',
    username: 'john',
    email: '[email protected]',
    country: 'France',
    department: 'IT Services',
    divisionName: 'IT',
    ...data,
});