Fold drupal_get_updaters() into Updater class, deprecate drupal_get_updaters()

Looking at usage I started to think that better to refactor it out of hooks at all. It looks more like event needed here.
On other hand in a light of composer this subsystem is very debatable

+++ b/core/includes/common.inc
@@ -1294,18 +1295,16 @@ function archiver_get_archiver($file) {
+ * @deprecated in Drupal 8.7.0 for removal before Drupal 9.0.0. Use
...
+  @trigger_error(__FUNCTION__ . '() is deprecated in Drupal 8.7.0 for removal before Drupal 9.0.0. Use \Drupal\Core\Updater\Updater::getUpdaterRegistry() instead. See change record.', E_USER_DEPRECATED);

+++ b/core/tests/Drupal/KernelTests/Core/Updater/DeprecatedDrupalGetUpdatersTest.php
@@ -0,0 +1,20 @@
+   * @expectedDeprecation drupal_get_updaters() is deprecated in Drupal 8.7.0 for removal before Drupal 9.0.0. Use \Drupal\Core\Updater\Updater::getUpdaterRegistry() instead. See change record.

Needs to increment the Drupal version to 8.8.0. This should be done also in CR (oh, no CR).

+++ b/core/includes/common.inc
@@ -1294,18 +1295,16 @@ function archiver_get_archiver($file) {
-  $updaters = &drupal_static(__FUNCTION__);

What if a 3rd party code is doing this?

drupal_static_reset('drupal_get_updaters');

The current code allows resetting the memory cache but the patch has removed that ability. So, we need a reset cache mechanism and also deprecate the usage of drupal_static_reset('drupal_get_updaters').

Fixed the above. Also moved to 8.8.x and added CR.

Re-rolling against 9.1.x-dev.

Drupal 9 was released, so we need to update the deprecation messages.

Proper re-roll (messages fixed) and clean-up

Also improved test
- module should test that data returned from old method
- no reason to split into 2 methods as both coupled and core installs twice for no reason

EDIT

+++ b/core/modules/update/src/Form/UpdateManagerInstall.php
@@ -199,9 +199,6 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
-    // Make sure the Updater registry is loaded.
-    drupal_get_updaters();

+++ b/core/modules/update/src/Form/UpdateReady.php
@@ -127,9 +127,6 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
-      // Make sure the Updater registry is loaded.
-      drupal_get_updaters();

Removed to make sure that static does not affect

Needs reroll and deprecated versions updating.

• Rerolled
• Fixed the Drupal version in deprecation messages, including the change record.
• Converted @expectedDeprecation annotation into assertions $this->expectDeprecation().

Should we just deprecate resetRegistryCache() as well, there seems little point in keeping it. No uses of drupal_get_updaters in contrib, let alone the static: http://grep.xnddx.ru/search?text=drupal_get_updaters&filename=

I'm not even sure I see the point in hook_updater_info, the only implementation is in system.module, but that's a wider issue - do we even really support updating anything else?

The remark from @longwave in #25 still needs to be addressed.
The patch looks good to me!.

I have manually re-rolled it against 9.3.x

Patch on #27 failed to apply, so another try with reroll.

Re-roll patch #27 is not appropriate, We missed some previous fixed changes according to #24. Please have a look.

Uploaded the updated patch for 9.3.x.

The remark from @longwave in #25 still needs to be addressed.

Reroll for 10.1.x.

Pretty sure this can be closed as outdated.

This function was deprecated outright.

The comment in 25 confused me until I realized it was just about deprecating the newly introduced static.

Compared the patches with the current state to confirm the deprecation covered everything in this.

The only thing this does that the main deprecation issue doesn't is deprecating calling drupal_static_reset for the function, but since the function is deprecated that seems fine to me.

Took a look at patches to apply credit as well since closed issues receive credit now.

I'm glad MRs are the primary way to review code, even with inter diffs patches are harder without the ui.

Thanks everyone for working on this!