Async Test import before Tests with cy.request

[deckdom]

Hello,

we use Cypress for integration tests and need to perform our setup and cleanup for our service with via the REST API.

We have a dedicated rest-client, where we can change the underlying driver which executes the request.
On default we would use fetch, but for cypress I made a custom one to use cy.request: Driver in question
So far, so basic.

Since the setup often depend on correct order and on the responses, everything is done with Promises.
Using it with the before and beforeAll hooks causes some troubles however:

Example Test:

describe('Example', () => {

    const IMPORTER = new EntityImporter();

    before(() => {
        cy.wrap(IMPORTER.clearClient(), { log: false }).then(() => {
            return cy.wrap(IMPORTER.cleanupTest(), { log: false, timeout: 60_000 });
        }).then(() => {
            return cy.wrap(IMPORTER.bootstrapSuite(TestSize.MINIMAL), { log: false, timeout: 60_000 });
        });
    });

    beforeEach(() => {
        cy.wrap(IMPORTER.clearClient(), { log: false }).then(() => {
            return cy.wrap(IMPORTER.cleanupTest(), { log: false, timeout: 60_000 });
        }).then(() => {
            return cy.wrap(IMPORTER.setupTest(TestSize.MINIMAL), { log: false, timeout: 60_000 });
        }).then(() => {
            cy.navigateToApp();
            cy.login(AUTH_ADMIN);
            cy.selectNode(IMPORTER.get(minimalNode)!.id);
        });
    });

    it('does some stuff ...', () => {});
});

Currently we use a chain of cy.wrap and then to make everything execute, but this isn't reliable.
Sometimes cypress is happy to execute these setups, sometimes it refuses with the following error:

CypressError: Cypress detected that you returned a promise from a command while also invoking one or more cy commands in that promise.

The command that returned the promise was:

  > `cy.wrap()`

The cy command you invoked inside the promise was:

  > `cy.request()`

Because Cypress commands are already promise-like, you don't need to wrap them or return your own promise.

Cypress will resolve your command with whatever the final Cypress command yields.

The reason this is an error instead of a warning is because Cypress internally queues commands serially whereas Promises execute as soon as they are invoked. Attempting to reconcile this would prevent Cypress from ever resolving.

https://on.cypress.io/returning-promise-and-commands-in-another-command

This error sometimes occurs, but usually works when being run in development/head-mode with the cypress app.
Running the tests via the CLI and headless however, consistently breaks on the same tests.
Other tests with the same approach execute fine however.
Therefore quite troublesome and hard to debug.

Of course I tried to use different approaches, but they all had different issues:

Using only a single wrap

before(() => {
    cy.wrap(
        IMPORTER.clearClient()
            .then(() => IMPORTER.cleanupTest())
            .then(() => IMPORTER.bootstrapSuite(TestSize.MINIMAL)),
        { log: false, timeout: 60_000 },
    );
});

Causes the same error as above, so no difference

Using then correctly without additional wrap

before(() => {
        cy.wrap(null, { log: false }).then({ timeout: 60_000 }, () => {
            return IMPORTER.clearClient()
                .then(() => IMPORTER.cleanupTest())
                .then(() => IMPORTER.bootstrapSuite(TestSize.MINIMAL));
        });
    });

This will lock up the first cy.request call - It'll never complete.
It seems to me it is scheduled, but never executed, so the handling of the response can't be handled.

Within the cypress-driver, we execute the request in a promise:

sentRequest = new Promise((resolve, reject) => {
    cy.request({
        // ... request data
    }).then(res => {
        let body = res.body;
        // ... processing
    });
});

I added a breakpoint to the first line within the then, but it never stopped there.
Adding a catch or any other standard error handling yielded absolutely nothing, and the initial then from the before hook will timeout.

Not using wrap or then at all

Can't be used very much, as for certain setups we have to load fixtures (binaries like test images and files) for upload,
therefore we have to mix these sometimes.

---

I'd greatly appreciate help with this, since I couldn't find anything relating to similar issues or projects which have a setup as complex as we have.
If you want to run the tests in question, then you are of course free to do so from our OSS repository.
In case any questions arise/more input is needed, please let me know.