FacetsSerializer views style plugin depends on optional rest module

am I correct in assuming that you don't have the rest module enabled? That might help in finding out why this fails.

This is a new error with 8.2.x. Didn't happen a couple weeks ago. I don't see any dependency listed in facets.info.yml for the Rest module, but enabling Rest did fix the error.

Either the facets.info.yml file needs to be updated, along with an update hook to enable it for existing sites. Or whatever caused Rest to suddenly be needed should be changed.

This prevents new installations from configuration so here is a patch that adds rest module dependency to the module.

This is not the correct way, I don't want facets to depend on this. Perhaps we should put the rest stuff in a submodule and have that one depend on rest?

I agree. We should put the rest stuff in a submodule. AFAIK the only way to avoid the error is enabling the REST module... so yes makes sense.

No reason in new module, just properly expose dependency.
This is how language module from core works

Proper title

updated IS

PS Tests are broken now so expect failures

Tests are failed because of search api #2777483: Unmet dependencies

I had a similar error with an event subscriber (https://www.drupal.org/node/2776235). This problem didn't occur before 8.1.6 after that I had to put extra dependencies to my install profile.

Bumping to critical as it's why the integration tests are failing:
https://travis-ci.org/mkalkbrenner/search_api_solr/jobs/149402468

I think #9 is a proper patch so called to retest, maybe test should be fixed as well to declare dependency on rest module

I just committed #2776711: non-existent service "search_api.results_static_cache", so sent this for another retest.

I sent this for a rest earlier and while the tests are green, it look like this is not sufficient:

drush en facets
The following extensions will be enabled: facets
Do you really want to continue? (y/n): y
Drush command terminated abnormally due to an unrecoverable error. [error]
Error: Class 'Drupal\rest\Plugin\views\style\Serializer' not found in
/.../modules/facets/src/Plugin/views/style/FacetsSerializer.php, line
22

The plugin is used in tests/facets_search_api_dependency/config/install/views.view.search_api_test_views_fulltext.ym.

Does rest module maybe need to be declared in test_dependencies?

@joachim: it's not just a problem in the tests, it's also a problem for real sites, and we really don't want to have rest as a hard dependency for all facets.

AFAIK, declaring a module in test_dependencies only tells the d.org test runner that the module is needed. It's not an actual dependency.

There's already this in facets.info:

test_dependencies:
  - search_api:search_api
  - drupal:views

AFAIK, declaring a module in test_dependencies only tells the d.org test runner that the module is needed. It's not an actual dependency.

There's already this in facets.info: ...

While that is true, that's not enough. It's not just for the tests that we need to resolve this, but also for the normal installation.

I did the changing into a submodule.

The installation on @StryKaizer's machine didn't work without this patch applied. With the patch it did. I forgot to move the test though, so I did that.

I'm confident we can commit this patch so that at least installs work again.

This should probably maybe resolve the issue.

The fails that are currently happening on the last patch are because facets are broken. We're trying to resolve that issue. However, there's nothing related to rest anymore.

So I feel that this patch resolves the issue at hand.

I think this is ready, but I'd like confirmation.

Separation looks ok, just wondered why not put submodules in to "modules" folder - separate issue

Suppose this needs change record pointing that you need to enable new module

> Separation looks ok, just wondered why not put submodules in to "modules" folder - separate issue

Yes please, do make that a separate issue, so the files move is its own commit. It makes a much cleaner git history.
Search API added code and moved files to a modules folder in a single commit, and I was trying to find a change in the git log and it was a painful commit to deal with!

OK to move the module to modules/
rtbc on the error

I agree with the modules directory, created #2798483: Move submodules into a modules folder.

I found a related core issue: #2796953: [regression] Plugins extending from classes of uninstalled modules lead to fatal error during discovery

Committed this, as it resolves at least some of our problems we currently have with facets.

I made sure to credit everyone I discussed this with at drupalcamp Ghent.

Thanks everyone for their help in figuring this one out.

Was already fixed.