How to integration test hooks that depend on session?

[JohannesKlauss]

I am trying to get a grasp on how to test component that depend on a user or that call resolvers depending on a server.

For simplicity reasons I just created a test database that is used inside the test environment.

This is a test file where I am trying to get a call to useCurrentUser to work:

import { Ctx, getSession, MiddlewareRequest as Req, MiddlewareResponse as Res } from 'blitz'
import httpMocks from 'node-mocks-http'
import { User, Profile } from 'db'

// This import is crucial, as it modifies global state by calling sessionMiddleware
// Most importantly, this sets the isAuthorized method in global.sessionConfig
import '../blitz.config'

interface CreateMockContextOptions {
  user?: Pick<User, 'id' | 'name' | 'role'> & { profile?: Profile }
  reqOptions?: httpMocks.RequestOptions
  resOptions?: httpMocks.ResponseOptions
}

// Based on https://github.com/blitz-js/blitz/issues/2654#issuecomment-904426530
// Creates a mock context for use in tests and scripts. Attempts to make it the
// "real deal" by calling the same initialization logic that creates actual
// session contexts.
export default async function createMockBlitzCtx<C extends Ctx>({
  user,
  reqOptions,
  resOptions,
}: CreateMockContextOptions = {}) {
  const mocks = httpMocks.createMocks<any, any>(reqOptions, resOptions)
  const mockReq: Req = mocks.req
  const mockRes: Res<C> = mocks.res

  // Ensures the response has the blitzCtx object which is required for
  // authorization checks
  await getSession(mockReq, mockRes)

  // Simulate login by saving public session data
  if (user) {
    // Need to use Object.assign instead of spread operator,
    // because $publicData is readonly (only has a getter)
    // make sure to add **your** session's public data
    Object.assign(mockRes.blitzCtx.session.$publicData, {
      id: user.id,
      role: user.role,
    })
  }

  return { req: mockReq, res: mockRes, ctx: mockRes.blitzCtx }
}

import { screen } from '@testing-library/react'
import { render } from 'test/utils'
import { TestProfile, TestUser } from 'test/testSetups/models/user'
import db from 'db'
import createMockBlitzCtx from 'test/createMockBlitzCtx'
import { useCurrentUser } from 'app/core/hooks/useCurrentUser'

beforeAll(async () => {
  const user = await db.user.create({ data: TestUser })
  await db.profile.create({ data: TestProfile })

  const ctx = await createMockBlitzCtx({ user }) // Where do i pass the ctx?
})

const Component = () => {
  const user = useCurrentUser()

  return (
    <span>{user?.name}</span>
  )
}

test('Should render', () => {
  render(<Component />)

  expect(screen.getByRole('button')).toBeInTheDocument()
})

I don't quite understand where I should pass the ctx to to have the render method working correctly.

When the tests call the getCurrentUser resolver it of course fails with cannot find property userId of undefined, because the session object is undefined.