Add admin-e2e-tests

[tomalec]

Changes proposed in this Pull Request:

Add admin-e2e-tests
to make sure our plugin does not break WooCommerce Admin.
Add @woocommerce/admin-e2e-tests dependency,
clone test suites from https://github.com/woocommerce/woocommerce/tree/trunk/tests/e2e/specs as suggested in the release post (pcShBQ-6A-p2).

It seems valuable, as we actually fail on two:

 FAIL  ../../../tests/e2e/specs/wc-admin/admin-analytics/analytics-overview.test.js (37.502s)
  Analytics pages
    ✓ a user should see 3 sections by default - Performance, Charts, and Leaderboards (157ms)
    ✓ should allow a user to remove a section (248ms)
    ✓ should allow a user to add a section back in (199ms)
    moving sections
      ✕ should not display move up for the top, or move down for the bottom section (95ms)
      ✕ should allow a user to move a section down (30012ms)
      ✕ should allow a user to move a section up (203ms)

Screenshots:

Detailed test instructions:

1. Checkout this branch

2.  npm i
    npm run docker:up
    npm run test:e2e

Changelog entry

Add - WooCommerce Admin tests suite.

[tomalec]

The tests fail due to admin-e2e expecting "Mode down" but get "Move Down", so it seems to be another dependency version mismatch.

[rrennick]

@tomalec This looks fine to me. They tested great locally. We have an issue to investigate why the analytics overview tests fail in some Mac environments.

  Analytics pages
    ✓ a user should see 3 sections by default - Performance, Charts, and Leaderboards (110ms)
    ✓ should allow a user to remove a section (153ms)
    ✕ should allow a user to add a section back in (548ms)
    moving sections
      ✓ should not display move up for the top, or move down for the bottom section (139ms)
      ✕ should allow a user to move a section down (521ms)
      ✕ should allow a user to move a section up (30011ms)

[tomalec]

Thank you @rrennick !

---

Now, there is a question for the Woogle team. Those tests require 5.6, but we are quite behind:

 * WC requires at least: 5.2
 * WC tested up to: 5.5

• Do we want to merge it?
• Do we want to skip failing ones or keep them failing? - They are simply failing due to the older version of WC, so there is nothing actionable on our end.

Currently, we are not running E2E on CI, so broken tests would not block anything.

[ecgan]

we are quite behind:

I think we would need to test and bump it up one day. Latest version of WooCommerce is 5.6.0 released about two weeks ago, so we should bump it to the following ("at least" version is L-2):

 * WC requires at least: 5.4
 * WC tested up to: 5.6

---

Those tests require 5.6...

• Do we want to merge it?

I think we would need to take the "lowest common denominator" approach (see previous related Slack thread in our team channel p1629975717010800/1629914514.272300-slack-CK365S85V) and make sure things work with L-2 version, so we probably shouldn't merge it now, but later when "at least" version becomes 5.6.0.

[tomalec]

I think we would need to take the "lowest common denominator" approach (see previous related Slack thread in our team channel p1629975717010800/1629914514.272300-slack-CK365S85V) and make sure things work with L-2 version, so we probably shouldn't merge it now, but later when "at least" version becomes 5.6.0.

I find it funky.
As I've seen admin-e2e-tests a way to check:

• whether our plugin does not break the core WC features
• whether we are compatible with the given version of WC

And from the results of the tests, you can tell, that we did not break a thing, and our plugin is compatible with 5.6, but we cannot use it before we bump our minimal version to 5.6. As what they check:

• whether the minimal WC version used by our plugin is compatible with the tests for the latest version of WC - which is not, as there was a small change in WC.

---

It would be nice to have a package that once used would run the tests for a WC version against that version of WC.

[tomalec]

This PR, grown old, and rotten a bit, I'll try to redo it on the latest develop.
Plus, given jestjs/jest#11781 is fixed, now I'd try to make it so we will run the test from node_modules directly, without the need for duplication, and wrapping increasing the risk of timeout.

[mikkamp]

Our E2E tests no longer rely on the packages from WooCommerce as they are deprecated. We use wp-env now, see PR #2030
So I'm closing this PR.