Description
t() should not be used in tests and assertions - if variables need to be added to strings, then format_string()/format_plural() should be used instead.
See https://www.drupal.org/project/drupal/issues/3133726 as well:
There is no need to use
t()in tests, unless we're testing translations, however in core we do not follow this consistently, which does not set a good example for new contributions.
Also see these (specifically for avoiding t() calls inside classes and Form Builders and using $this->t() instead):
- https://www.drupal.org/project/drupal/issues/3113904
- https://www.drupal.org/project/drupal/issues/3122912
If you google drupal do not use t() in tests, a bunch of issues in d.org contrib project will come up.
I am not 100% sure, but I believe that this should also result in faster-running tests, which should be a DX+ for contributors.
PHPCS
We should also add PHPCS rules to prevent these from creeping back into the tests code.
Documentation
https://docs.backdropcms.org/api/backdrop/core%21includes%21bootstrap.inc/function/format_string/1 mentions the following:
In most cases, you should use
t()rather than calling this function directly, since it will translate the text (on non-English-only sites) in addition to formatting it.
We should add to that ^^ that tests are an exception where format_string() should be used instead of t(). Perhaps there's other places that we need to update as well.