EntityResource: Provide comprehensive test coverage for RestResourceConfig entity

As one of the maintainers of the REST module, I figured I'd take this one on :)

1. +++ b/core/modules/rest/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigResourceTestBase.php
   @@ -0,0 +1,103 @@
   +  /**
   +   * {@inheritdoc}
   +   */
   +  public static $modules = ['dblog'];
   

   Copy and paste error?

2. +++ b/core/modules/rest/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigResourceTestBase.php
   @@ -0,0 +1,103 @@
   +  /**
   +   * @var \Drupal\user\RoleInterface
   +   */
   +  protected $entity;
   

   Copy/paste error? Also need description.

3. +++ b/core/modules/rest/tests/src/Functional/EntityResource/RestResourceConfig/RestResourceConfigResourceTestBase.php
   @@ -0,0 +1,103 @@
   +      'dependencies' => [
   +        'module' => [
   +          'dblog',
   +          'serialization',
   +          'user',
   +        ],
   

   I don't understand why these expected dependencies pass? dblog? why not REST itself?

1. No: we're testing with the dblog @RestResource plugin :)
2. Yes! Thanks :)
3. This is correct. Explanation:
   • dblog because \Drupal\Tests\rest\Functional\EntityResource\RestResourceConfig\RestResourceConfigResourceTestBase::createEntity() creates a REST resource config entity that uses the dblog @RestResource plugin.
   • serialization because this uses the json serialization format, which is provided by the serialization module
   • user because this uses the cookie authentication mechanism, which is provided by the user module

@Wim Leers ok thanks

That only leaves my question in the last part of #6.3

Why would REST module also not be a dependency. I figure it has something to do with my lack of understanding of configuration management but it seems the config entity type is declared by the REST module so you would need it.

I see what you're saying now. I can see why you come to that conclusion, but that's indeed not how the config system works.

The rest_resource_config config entity type is declared by the rest module. Without the rest module, the rest_resource_config entity type simply does not exist. (And then this configuration would simply be ignored: it'd be a meaningless blob of data.)

See for example filter.format.basic_html. It also doesn't list the filter module. Or taxonomy.vocabulary.tags, which also doesn't list the taxonomy module.

@Wim Leers ok thanks for the explanation.

RTBC then!

DrupalCI infra fail.

Committed and pushed c522c8f to 8.4.x and 09787b9 to 8.3.x. Thanks!

Backported to 8.3.x because its tests only.