API page: https://api.drupal.org/api/drupal/core%21core.api.php/group/testing/8.5.x
The Automated Tests topic, which is a @defgroup section in core/core.api.php, needs an update to remove mention of Simpletest from it. Simpletest classes are deprecated.
My suggestion for how to do this:
a) First line: Remove "and Simpletest"
b) "Writing functional tests" section:
- This section is actually mostly about writing Kernel tests, so change the header to "Writing kernel tests (PHPUnit)".
- Remove the first bullet point about Simpletest
- Write a new first paragraph that starts something like this:
Kernel tests extend \Drupal\KernelTests\KernelTestBase, and use PHPUnit as their underlying framework.
And then continue with most of what is currently in the second bullet point (remove that bullet item) that explains a bit about how to use KernelTestBase. It will need some rewording.
- Edit the rest of the bullet points, because they need the information that is currently under the "Writing functional tests (PHPUnit)" section instead, except that the test needs to go in the Kernel subdirectory instead of Functional.
- Remove the link to simpletest docs and replace it with a link to https://www.drupal.org/docs/8/phpunit
d) In the bottom section about running tests, take out the mention of simpletest.