Properly deprecate drupal_get_profile()

The one remark I have is that we usually seem to mention the version of drupal a function was deprecated in and the trigger_error here doesn't seem to be doing that.

I don't have any other remarks, but I don't feel confident enough about my knowledge of the installer system to RTBC this patch.

This looks really great already!

1. +++ b/core/lib/Drupal/Core/Extension/ExtensionDiscovery.php
   index 754be196c3..03ffc3438c 100644
   --- a/core/lib/Drupal/Core/Extension/ModuleInstaller.php
   
   --- a/core/lib/Drupal/Core/Extension/ModuleInstaller.php
   +++ b/core/lib/Drupal/Core/Extension/ModuleInstaller.php
   
   +++ b/core/lib/Drupal/Core/Extension/ModuleInstaller.php
   +++ b/core/lib/Drupal/Core/Extension/ModuleInstaller.php
   @@ -350,7 +350,7 @@ public function uninstall(array $module_list, $uninstall_dependents = TRUE) {
   
   @@ -350,7 +350,7 @@ public function uninstall(array $module_list, $uninstall_dependents = TRUE) {
        if ($uninstall_dependents) {
          // Add dependent modules to the list. The new modules will be processed as
          // the foreach loop continues.
   -      $profile = drupal_get_profile();
   +      $profile = $this->kernel->getContainer()->getParameter('install_profile');
          foreach ($module_list as $module => $value) {
   

   I'm curious whether it is worth injecting the parameter normally, instead of going via the kernel to the container.

2. +++ b/core/tests/Drupal/Tests/Core/Bootstrap/DrupalGetProfileTest.php
   @@ -0,0 +1,66 @@
   +  protected function setUp() {
   +    parent::setUp();
   +    include __DIR__ . '/../../../../../includes/bootstrap.inc';
   +  }
   

   In case you want to make your life easier ... there is $this->root

Should we postpone this issue based on #4? Otherwise it looks like the remarks @dawehner had in #8 are resolved.

Updating status now that the other issue has been resolved.

Rerolled in the separate JUST_REROLL patch.
Changes in the second patch:
- Removed changes in a create method (mentioned in #16 comment)
- Fixed CS issues related to the deprecation messages and legacy test.

1. +++ b/core/tests/Drupal/FunctionalTests/Installer/InstallerTest.php
   @@ -27,6 +27,14 @@ public function testInstaller() {
   +    // Ensure the profile has a weight of 1000.
   

   Why 1000?

2. +++ b/core/tests/Drupal/FunctionalTests/Installer/InstallerTest.php
   @@ -27,6 +27,14 @@ public function testInstaller() {
   +    $this->assertEquals(1000, $extensions['testing']->weight);
   +
      }
   

   Nit: extraneous blank line 🤓

3. +++ b/core/tests/Drupal/Tests/Core/Bootstrap/DrupalGetProfileTest.php
   @@ -0,0 +1,71 @@
   + * @group Bootstrap
   + * @group legacy
   + * @see drupal_get_profile()
   + * @runTestsInSeparateProcesses
   + * @preserveGlobalState disabled
   

   I think this is the longest list of annotations I've ever seen in a test :D

4. +++ b/core/tests/Drupal/Tests/Core/Bootstrap/DrupalGetProfileTest.php
   @@ -0,0 +1,71 @@
   +   * Test drupal_get_profile() deprecation.
   

   Nit: s/Test/Tests/

5. +++ b/core/tests/Drupal/Tests/Core/Bootstrap/DrupalGetProfileTest.php
   @@ -0,0 +1,71 @@
   +  public function providerTestDrupalGetProfile() {
   

   🤔 I thought we usually named the provider providerFooBar if the test method it's for is called testFooBar?

   This is naming it providerTestFoobar instead.

6. +++ b/core/tests/Drupal/Tests/Core/Bootstrap/DrupalGetProfileTest.php
   @@ -0,0 +1,71 @@
   +    $tests['install_state_with_profile'] = ['test_profile', ['parameters' => ['profile' => 'test_profile']]];
   +    $tests['install_state_with_no_profile_overriding_container_profile'] = [NULL, ['parameters' => []], 'test_profile'];
   +    $tests['no_install_state_with_container_profile'] = ['container_profile', NULL, 'container_profile'];
   

   Nit: Let's format this to fit within 80 cols.

Regarding #20.1:
See install_finished() function in install.core.inc file:

  // Installation profiles are always loaded last.
  module_set_weight($profile, 1000);

#21: TIL! Thanks 🙏

#20.2: fixed
#20:4: fixed
#20.5: fixed
#20.6: fixed

Test was renamed to DrupalGetProfileLegacyTest.php

Addressed #20

Committed eb9dc11 and pushed to 8.8.x. Thanks!