D10: ModuleHandler::getImplementations() deprecation

Thanks, there are two issues with it:

a), we need to keep both versions, to support 9.3 still. See the patch in #3278537: D10 compatibility | Declaration of Drupal\field_group\Routing\RouteSubscriber::getSubscribedEvents() must be compatible with Drupal\Core\Routing\RouteSubscriberBase::getSubscribedEvents(), check core version, then do one or the other.
b) I don't think this is working. You are now inside a nested function, that return TRUE/FALSE is not going anywhere. seems like we don't have test coverage of this? We need to have a by reference variable that we set to TRUE/FALSE and then return that. Also no need to make $results an array. And to keep the optimization, we need to check if $result is already TRUE and skip the call then, so:

if ($result === FALSE) {
  $result = $hook();
}

+++ b/src/AliasUniquifier.php
@@ -119,15 +119,28 @@ class AliasUniquifier implements AliasUniquifierInterface {
+    if (method_exists($this->moduleHandler, 'invokeAllWith')) {
+      $this->moduleHandler->invokeAllWith($hook, function (callable $hook, string $module) {
+        $results[$module] = $hook();
+        if (!empty($results)) {
+          // As soon as the first module says that an alias is in fact reserved,
+          // then there is no point in checking the rest of the modules.
+          return TRUE;
+        }

this stores the return in a results array but then uses it as a boolean. you need to assign to $results directly.

Also, you can't return anymore, you're inside a function, it goes nowhere. you need to use (&$result) so that the result if it can be returned.

Interesting. I guess that works, I do wonder what the performance impact is, getImplementations() is cached and this is likely going to call hasImplementations() 100+ times on sites with many modules. And most sites won't actually have an implementation of this hook.

So I'll go with #8, we can eventually clean this up and do the check directly in the callback.

Also sneaking in D10 test fixes that didn't fail before.

Ah, need to pass in the Url object, forgot that you can do that.

Committed.