Simpletest does not reset the $theme* globals

I ran into this problem trying to run the forum module test class ForumTestCase with the run-tests.sh script. It was invoking theme functions from the site's custom theme, causing the output to deviate from the test's expectations. When I ran the same test class from the UI, using the admin theme, I had no failures.

Applying this patch fixed the problem.

I too just encountered this whilst implementing hook_custom_theme() with the Bootstrap theme and running Views tests through the web interface.

My initial proposed fix for Views was very similar:

  abstract class ViewsSqlTest extends ViewsTestCase {
    ...

    public function setUp(array $modules = array()) {
      ...

+     global $theme;
+     $theme = NULL;
+     drupal_theme_rebuild();
    }

    ...
  }

However before submitting an issue I figured that actually other modules would also likely be affected, so better to fix it upstream.

Found this issue, and your code works perfectly.

My only comment is it looks like there is unnecessary whitespace being added here:

+ <<< Why?
+    // Reset the theme globals.

But other than that it looks good to go.

Thanks for the patch. We are not going to introduce new dynamic properties, as these would cause deprecation messages in PHP 8.2.

+    $this->originalTheme = $theme;
+    $this->originalThemeKey = $theme_key;
+    $this->originalThemePath = $theme_path;

There is an issue which corrects this for all existing properties in the DrupalWebTestCase class, see: #3304882: [D7 PHP 8.2] Deprecated function: Creation of dynamic property in DrupalWebTestCase->prepareEnvironment(). This patch needs to be updated to correctly define all new properties, so they do not trigger deprecation messages in PHP 8.2.

Random testbot error switched the status to Needs Work, but let's keep it there until the dynamic properties are resolved.

The interdiff is a bit confusing but I'm pretty sure all I've actually changed is declaring the properties to avoid the problem outlined in #6.

It really didn't like the nearly 300 lines of offset I guess.

This looks good, thanks! I have tested it manually (according to the steps outlined in the issue summary) and before the patch, there were multiple failures:

Breadcrumbs were displayed

After the patch is applied, the failures are gone.

Thank you!