Remove EntityInterface->getSystemPath(), all its implementations and related usage

There is exactly one call to it in core. And that's the test for that method.

There's no need to remove that separately.

Found another one in CommentTranslationUITest (?)

Use $entity->urlInfo()

+++ b/core/modules/comment/src/Tests/CommentTranslationUITest.php
@@ -138,7 +138,7 @@ protected function doTestPublishedStatus() {
+    $path = $entity->static::urlInfo('edit-form');

it's not static method

+++ b/core/modules/comment/src/Tests/CommentTranslationUITest.php
@@ -138,7 +138,7 @@ protected function doTestPublishedStatus() {
+    $path = $entity->urlInfo('edit-form');

Just changing to urlInfo makes that particular test case to fail. Need to troubleshoot to get more info about this test case execution

1. +++ b/core/modules/comment/src/Tests/CommentTranslationUITest.php
   @@ -138,7 +138,7 @@ protected function doTestPublishedStatus() {
        $entity = entity_load($this->entityTypeId, $this->entityId, TRUE);
   -    $path = $entity->getSystemPath('edit-form');
   +    $path = $entity->urlInfo('edit-form');
   

   urlInfo returns an object, so you should rename it to $url.

   The problem is that you can't pass in the language to drupalPostForm() like the code below is doing if you have an object, instead you need to pass it to urlInfo().

   But that means you need to move the code inside the foreach loop, so you get a different object for each language.

2. +++ b/core/tests/Drupal/Tests/Core/Entity/EntityUrlTest.php
   @@ -199,38 +199,6 @@ public function testUrl() {
   -   * Tests the getPathByAlias() method.
   -   *
   -   * @covers ::getSystemPath
   -   */
   -  public function testGetSystemPath() {
   -    $entity_type = $this->getMock('Drupal\Core\Entity\EntityTypeInterface');
   

   As I said, this is the test for the function. Removing the test without removing the method is wrong IMHO. That said, I don't think we need an issue to fix a single call, we can probably just remove it all here?

removed usage and function with test

+++ b/core/modules/comment/src/Tests/CommentTranslationUITest.php
@@ -138,12 +138,12 @@ protected function doTestPublishedStatus() {
     foreach ($this->langcodes as $langcode) {
+      $path = $entity->urlInfo('edit-form', ['language' => $languages[$langcode], 'absolute' => TRUE])->toString();
       $user = $this->drupalCreateUser();

You can pass a UrlInfo() object to drupalPostForm(), that should eliminate the need for the absolute option and ->toString(), rename $path to $url then.

Patch looks good to me now. I'm not aware of any contrib modules still using this, so we should be pretty safe.

Issue title needs to be updated to reflect that we are actually removing the method here.

And we need a beta evaluation and prepare a change record. The only mention that I can find is the introduction of the method in https://www.drupal.org/list-changes/published?keywords_description=getSy....

Once this is committed, we should also review that change record and update it for current standards.

Added beta evaluation and changed title

Ok, this was deprecated a long time ago, so I think it's OK to remove it?

As mentioned above, couldn't find any contrib usages anyway and it was only introduced a year ago...

I don't think we need a new change record for this as mentioned, we can update the existing one and just remove this part, or if we want to we can say that if you really, really need the system path (path system still does for example), you can use $entity->urlInfo()->getInternalPath().

+1 to the RTBC

Committed c31fec2 and pushed to 8.0.x. Thanks!

Thanks for adding the beta evaluation to the issue summary.

My patch in https://www.drupal.org/node/2497247 failed because of
Fatal error: Call to undefined method Drupal\block\Entity\Block::getSystemPath() in /var/lib/drupaltestbot/sites/default/files/checkout/sites/default/modules/token/src/Tests/TokenBlockTest.php on line 54
Can you please include that, too? Thanks!

token is a contrib module and already has a patch.