Improve Entity URI checking in menu link migration

Having reviewed the changes to the D6 equivalent, LinkUri, it seems there is a lot of overlap and the same process plugin can now be used for both (with minimal tweaks).

Add a mock node so that the expected entity uri can be generated.

+++ b/core/modules/menu_link_content/src/Plugin/migrate/process/LinkUri.php
@@ -63,6 +63,9 @@ public function transform($value, MigrateExecutableInterface $migrate_executable
+      if ($path == '<front>') {
+        $path = '';
+      }

Missed that detail in the initial D7 patch. I think we should rather use route:<front> in that case, (and skip the internal: stuff in that case. That should be a tad more performant when loading that actual link later.

@tstoeckler Can you explain what you mean, please? How is route:<front> relevant in this situation?

Setting back to "Needs review" - appears to have been a test-bot glitch.

So, what we end up saving as the link URI matters for the performance of rendering the actual links later in the Drupal site. internal: is the slowest option, but it is used as the fallback as it always work.

That is why we do that dance to try to convert them into entity: URIs as that will make the links much faster to load later on.

And similarly using route:<front> is more performant than internal:/ (or whatever) so we should convert that, as well.

Does that make more sense?

Thanks, @tstoeckler, that does make sense, but the UI does not handle route:<front> elegantly - it displays the entire string. This goes against the associated text that says simply use <front> (which then gets converted to internal:/).

I suggest committing this "as is" and creating a separate ticket to associate route:<front> with <front> then coming back to change this.

Mhhh ... interesting. Yeah, that's fair, I will open a follow-up.

@tstoeckler so would you be happy to set this to RTBC?

@mikeryan assigned this to himself 20hours ago, so not sure if he wants to do any improvements or follow-ups, so would like confirmation from him first. But for me this looks RTBC.

Opened #2832382: Try to use route URI scheme in link migration for <front> (and possibly others) for #12 / #13.

Yep, assigned to myself to review then there was a flurry of activity, so I waited for it to die down.

I'm not particularly conversant with routing, so I defer to @tstoeckler there. The purely migration side looks good to me - I hesitated on seeing a test removed and not replaced, but I see that this test becomes redundant with LinkUriTest, so good to go...

Thanks!

This should probably be related to #2761389: Migrate process plugin internal_uri and d7_internal_uri changed to link_uri and the CR updated.