Using an async function in describe instead of beforeAll()?

[katangafor]

When using beforeAll(), the tests don't have access to any variables created inside the beforeAll callback.

Is there anything wrong with doing something like this?

describe("awesome test suite", async () => {
  const fakeClient = await prisma.client.create({
    data: {
      name: "hello mr. client"
    }
  })

  test("client has an id", async () => {
    expect(fakeClient.id).toBeDefined()
  })
})

[sheremet-va]

Vitest runs tests in two phases:

1. Collect phase -- all tests are collected, but no before/after/test functions are called yet
2. Execute phase -- all collected tests and hooks are executed in order

If you don't use a hook, then prisma is called during the collection phase. This doesn't really matter unless you want your collection phase to be fast. For example, when using #4240 in the future (IDE integrations run your code and create prisma instances, but don't call after hooks so they are never cleared which might case issues).

[SimonEast]

I've just been attempting the same thing, however I've experienced weird issues regarding the ordering of execution, presumably because of the different phases that @sheremet-va described. For example when I have:

Describe 1
- Test 1a
- Test 1b
Describe 2
- Test 2a
- Test 2b

While you may expect everything to run in sequence, instead what happens is Describe 1 and Describe 2 are run first, before all of the tests, and then the tests are run 1a, 1b, 2a, 2b.

In my case a shared/global variable was getting modified by Describe 2 and affecting tests 1a and 1b, even though it comes later in the script.

So I think I will have to refactor to define the variable inside the describe (so they can be accessed by all tests) but use the beforeAll() method to populate it. Then things should run in the expected order, like this:

- Describe 1
- Describe 2
- beforeAll() 1
- Test 1a
- Test 1b
- beforeAll() 2
- Test 2a
- Test 2b

[alexey-sh]

describe('DB', () => {
    let posts: Post[] = [];
    beforeAll(async () => {
        const loadedPosts = await prisma.post.findMany({ where: {}});
        posts.push(...loadedPosts);
    });
    describe('lol', () => {
        test('kek', () => {
            console.log(posts.length);
            expect(true).toBe(true)
        })
        test.each(posts)('Test $external_id', async (post) => {
            const content = getPostText(post.external_id, post.data, post.data_source);
            await expect(content).toMatchFileSnapshot(`./db-snapshots/${post.data_source}_${post.external_id}.txt`);
        });
    });
});

test.each does not handled. So the beforeAll approach does not work for me. However i see in console this:

stdout | test/content-extractor.test.ts > DB > lol > kek
224

[SimonEast]

Does it work if you put the beforeAll() inside the describe('lol'... section?

And is getPostText() an async function? If so, maybe you need to await it before you call expect().

[hi-ogawa]

This is expected. As explained in #4858 (comment),

• collection phase: run describe and test.each(posts)
• execution phase: run () => { ... } functions from beforeAll(() => { ... }) and test('kek', () => { ... }), test.each(posts)('...', () => { ... })

[alexey-sh]

Does it work if you put the beforeAll() inside the describe('lol'... section?

And is getPostText() an async function? If so, maybe you need to await it before you call expect().

no it does not.
getPostText is not async