Issue #3205480 by alexpott, andypost, Wim Leers, catch, kim.pepper, longwave: Drop PECL YAML library support in favor of only Symfony YAML

(cherry picked from commit 25dc2f1480ddd83896b5cba9cd0488b9ea8abe9c)

core/.eslintignore

@@ -9,6 +9,9 @@ modules/system/tests/fixtures/HtaccessTest/access_test.yml
 modules/system/tests/themes/test_theme_libraries_empty/test_theme_libraries_empty.info.yml
 tests/Drupal/Tests/Core/Asset/library_test_files/empty.libraries.yml
 tests/Drupal/Tests/Core/Asset/library_test_files/invalid_file.libraries.yml
+tests/Drupal/Tests/Composer/Plugin/Scaffold/fixtures/drupal-assets-fixture/assets/default.services.yml
+tests/Drupal/Tests/Composer/Plugin/Scaffold/fixtures/drupal-profile/assets/profile.default.services.yml
+modules/sdc/tests/themes/sdc_theme_test/components/bar/bar.component.yml
 
 # Temporary until they are brought up to standards
 scripts/**/*

core/lib/Drupal/Component/Serialization/Yaml.php

@@ -2,37 +2,43 @@
 
 namespace Drupal\Component\Serialization;
 
+use Drupal\Component\Serialization\Exception\InvalidDataTypeException;
+use Symfony\Component\Yaml\Dumper;
+use Symfony\Component\Yaml\Parser;
+use Symfony\Component\Yaml\Yaml as SymfonyYaml;
+
 /**
- * Provides a YAML serialization implementation.
- *
- * Proxy implementation that will choose the best library based on availability.
+ * Provides a YAML serialization implementation using symfony/yaml.
  */
 class Yaml implements SerializationInterface {
 
-  /**
-   * The YAML implementation to use.
-   *
-   * @var \Drupal\Component\Serialization\SerializationInterface
-   */
-  protected static $serializer;
-
   /**
    * {@inheritdoc}
    */
   public static function encode($data) {
-    // Instead of using \Drupal\Component\Serialization\Yaml::getSerializer(),
-    // always using Symfony for writing the data, to reduce the risk of having
-    // differences if different environments (like production and development)
-    // do not match in terms of what YAML implementation is available.
-    return YamlSymfony::encode($data);
+    try {
+      // Set the indentation to 2 to match Drupal's coding standards.
+      $yaml = new Dumper(2);
+      return $yaml->dump($data, PHP_INT_MAX, 0, SymfonyYaml::DUMP_EXCEPTION_ON_INVALID_TYPE | SymfonyYaml::DUMP_MULTI_LINE_LITERAL_BLOCK);
+    }
+    catch (\Exception $e) {
+      throw new InvalidDataTypeException($e->getMessage(), $e->getCode(), $e);
+    }
   }
 
   /**
    * {@inheritdoc}
    */
   public static function decode($raw) {
-    $serializer = static::getSerializer();
-    return $serializer::decode($raw);
+    try {
+      $yaml = new Parser();
+      // Make sure we have a single trailing newline. A very simple config like
+      // 'foo: bar' with no newline will fail to parse otherwise.
+      return $yaml->parse($raw, SymfonyYaml::PARSE_EXCEPTION_ON_INVALID_TYPE);
+    }
+    catch (\Exception $e) {
+      throw new InvalidDataTypeException($e->getMessage(), $e->getCode(), $e);
+    }
   }
 
   /**
@@ -44,21 +50,15 @@ class Yaml implements SerializationInterface {
 
   /**
    * Determines which implementation to use for parsing YAML.
+   *
+   * @deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. There is no
+   *  replacement.
+   *
+   * @see https://www.drupal.org/node/3415489
    */
   protected static function getSerializer() {
-
-    if (!isset(static::$serializer)) {
-      // Use the PECL YAML extension if it is available. It has better
-      // performance for file reads and is YAML compliant.
-      if (extension_loaded('yaml')) {
-        static::$serializer = YamlPecl::class;
-      }
-      else {
-        // Otherwise, fallback to the Symfony implementation.
-        static::$serializer = YamlSymfony::class;
-      }
-    }
-    return static::$serializer;
+    @trigger_error('Calling ' . __METHOD__ . '() is deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. There is no replacement. See https://www.drupal.org/node/3415489', E_USER_DEPRECATED);
+    return YamlSymfony::class;
   }
 
 }

core/lib/Drupal/Component/Serialization/YamlSymfony.php

@@ -2,6 +2,8 @@
 
 namespace Drupal\Component\Serialization;
 
+@trigger_error('The ' . __NAMESPACE__ . '\YamlSymfony is deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. Use \Drupal\Component\Serialization\Yaml instead. See https://www.drupal.org/node/3415489', E_USER_DEPRECATED);
+
 use Drupal\Component\Serialization\Exception\InvalidDataTypeException;
 use Symfony\Component\Yaml\Parser;
 use Symfony\Component\Yaml\Dumper;
@@ -9,6 +11,11 @@ use Symfony\Component\Yaml\Yaml as SymfonyYaml;
 
 /**
  * Default serialization for YAML using the Symfony component.
+ *
+ * @deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. Use
+ *   \Drupal\Component\Serialization\Yaml instead.
+ *
+ * @see https://www.drupal.org/node/3415489
  */
 class YamlSymfony implements SerializationInterface {
 
@@ -16,6 +23,7 @@ class YamlSymfony implements SerializationInterface {
    * {@inheritdoc}
    */
   public static function encode($data) {
+    @trigger_error('Calling ' . __METHOD__ . '() is deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. Use \Drupal\Component\Serialization\Yaml::encode() instead. See https://www.drupal.org/node/3415489', E_USER_DEPRECATED);
     try {
       // Set the indentation to 2 to match Drupal's coding standards.
       $yaml = new Dumper(2);
@@ -30,6 +38,7 @@ class YamlSymfony implements SerializationInterface {
    * {@inheritdoc}
    */
   public static function decode($raw) {
+    @trigger_error('Calling ' . __METHOD__ . '() is deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. Use \Drupal\Component\Serialization\Yaml::decode() instead. See https://www.drupal.org/node/3415489', E_USER_DEPRECATED);
     try {
       $yaml = new Parser();
       // Make sure we have a single trailing newline. A very simple config like
@@ -45,6 +54,7 @@ class YamlSymfony implements SerializationInterface {
    * {@inheritdoc}
    */
   public static function getFileExtension() {
+    @trigger_error('Calling ' . __METHOD__ . '() is deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. Use \Drupal\Component\Serialization\Yaml::getFileExtension() instead. See https://www.drupal.org/node/3415489', E_USER_DEPRECATED);
     return 'yml';
   }
 

core/lib/Drupal/Core/Serialization/Yaml.php

@@ -1,28 +1,7 @@
 <?php
-
-namespace Drupal\Core\Serialization;
-
-use Drupal\Core\Site\Settings;
-use Drupal\Component\Serialization\Yaml as ComponentYaml;
+// phpcs:ignoreFile
 
 /**
- * Provides a YAML serialization implementation.
- *
- * Allow settings to override the YAML implementation resolution.
+ * Provides a BC layer for Drupal\Core\Serialization\Yaml.
  */
-class Yaml extends ComponentYaml {
-
-  /**
-   * {@inheritdoc}
-   */
-  protected static function getSerializer() {
-    // Allow settings.php to override the YAML serializer.
-    if (!isset(static::$serializer) &&
-      $class = Settings::get('yaml_parser_class')) {
-
-      static::$serializer = $class;
-    }
-    return parent::getSerializer();
-  }
-
-}
+class_alias('\Drupal\Component\Serialization\Yaml', '\Drupal\Core\Serialization\Yaml');

core/lib/Drupal/Core/Site/Settings.php

@@ -42,6 +42,10 @@ final class Settings {
       'replacement' => '',
       'message' => 'The "block_interest_cohort" setting is deprecated in drupal:9.5.0. This setting should be removed from the settings file, since its usage has been removed. See https://www.drupal.org/node/3320787.',
     ],
+    'yaml_parser_class' => [
+      'replacement' => '',
+      'message' => 'The "yaml_parser_class" setting is deprecated in drupal:10.3.0. This setting should be removed from the settings file, since its usage has been removed. See https://www.drupal.org/node/3415489.',
+    ],
   ];
 
   /**

core/modules/config/tests/src/Functional/ConfigSingleImportExportTest.php

@@ -192,21 +192,9 @@ EOD;
     ];
     $this->drupalGet('admin/config/development/configuration/single/import');
     $this->submitForm($edit, 'Import');
-    if (extension_loaded('yaml')) {
-      // If the yaml extension is loaded it will work but not create the PHP
-      // object.
-      $this->assertSession()->pageTextContains('Are you sure you want to update the second test configuration?');
-      $this->submitForm([], 'Confirm');
-      $entity = $storage->load('second');
-      $this->assertSession()->pageTextContains('The configuration was imported successfully.');
-      $this->assertIsString($entity->label());
-      $this->assertStringContainsString('ObjectSerialization', $entity->label(), 'Label contains serialized object');
-    }
-    else {
-      // If the Symfony parser is used there will be an error.
-      $this->assertSession()->responseContains('The import failed with the following message:');
-      $this->assertSession()->responseContains('Object support when parsing a YAML file has been disabled');
-    }
+    // @see \Drupal\Tests\Component\Serialization\YamlSymfonyTest:: testDecodeObjectSupportDisabled()
+    $this->assertSession()->responseContains('The import failed with the following message:');
+    $this->assertSession()->responseContains('Object support when parsing a YAML file has been disabled');
   }
 
   /**

core/modules/sdc/tests/themes/sdc_theme_test/components/bar/bar.component.yml

@@ -1,2 +1 @@
-# YAML linter does not allow empty files, setting it to NULL tests the same.
-null
+# This file is intentionally left empty

core/phpstan.neon.dist

@@ -15,6 +15,10 @@ parameters:
     - .
     - ../composer
 
+  bootstrapFiles:
+    # Load aliases.
+    - lib/Drupal/Core/Serialization/Yaml.php
+
   excludePaths:
     # Skip sites directory.
     - ../sites

core/tests/Drupal/Tests/Component/Serialization/YamlSymfonyTest.php

@@ -6,15 +6,18 @@ namespace Drupal\Tests\Component\Serialization;
 
 use Drupal\Component\Serialization\Exception\InvalidDataTypeException;
 use Drupal\Component\Serialization\YamlSymfony;
+use Symfony\Bridge\PhpUnit\ExpectDeprecationTrait;
 
 /**
  * Tests the YamlSymfony serialization implementation.
  *
  * @group Drupal
  * @group Serialization
+ * @group legacy
  * @coversDefaultClass \Drupal\Component\Serialization\YamlSymfony
  */
 class YamlSymfonyTest extends YamlTestBase {
+  use ExpectDeprecationTrait;
 
   /**
    * Tests encoding and decoding basic data structures.
@@ -24,6 +27,8 @@ class YamlSymfonyTest extends YamlTestBase {
    * @dataProvider providerEncodeDecodeTests
    */
   public function testEncodeDecode($data) {
+    $this->expectDeprecation("Calling Drupal\Component\Serialization\YamlSymfony::encode() is deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. Use \Drupal\Component\Serialization\Yaml::encode() instead. See https://www.drupal.org/node/3415489");
+    $this->expectDeprecation("Calling Drupal\Component\Serialization\YamlSymfony::decode() is deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. Use \Drupal\Component\Serialization\Yaml::decode() instead. See https://www.drupal.org/node/3415489");
     $this->assertEquals($data, YamlSymfony::decode(YamlSymfony::encode($data)));
   }
 
@@ -34,6 +39,7 @@ class YamlSymfonyTest extends YamlTestBase {
    * @dataProvider providerDecodeTests
    */
   public function testDecode($string, $data) {
+    $this->expectDeprecation("Calling Drupal\Component\Serialization\YamlSymfony::decode() is deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. Use \Drupal\Component\Serialization\Yaml::decode() instead. See https://www.drupal.org/node/3415489");
     $this->assertEquals($data, YamlSymfony::decode($string));
   }
 
@@ -43,6 +49,7 @@ class YamlSymfonyTest extends YamlTestBase {
    * @covers ::encode
    */
   public function testEncode() {
+    $this->expectDeprecation("Calling Drupal\Component\Serialization\YamlSymfony::encode() is deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. Use \Drupal\Component\Serialization\Yaml::encode() instead. See https://www.drupal.org/node/3415489");
     // cSpell:disable
     $this->assertEquals('foo:
   bar: \'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vivamus sapien ex, venenatis vitae nisi eu, posuere luctus dolor. Nullam convallis\'
@@ -54,6 +61,7 @@ class YamlSymfonyTest extends YamlTestBase {
    * @covers ::getFileExtension
    */
   public function testGetFileExtension() {
+    $this->expectDeprecation("Calling Drupal\Component\Serialization\YamlSymfony::getFileExtension() is deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. Use \Drupal\Component\Serialization\Yaml::getFileExtension() instead. See https://www.drupal.org/node/3415489");
     $this->assertEquals('yml', YamlSymfony::getFileExtension());
   }
 
@@ -63,6 +71,7 @@ class YamlSymfonyTest extends YamlTestBase {
    * @covers ::decode
    */
   public function testError() {
+    $this->expectDeprecation("Calling Drupal\Component\Serialization\YamlSymfony::decode() is deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. Use \Drupal\Component\Serialization\Yaml::decode() instead. See https://www.drupal.org/node/3415489");
     $this->expectException(InvalidDataTypeException::class);
     YamlSymfony::decode('foo: [ads');
   }
@@ -72,7 +81,8 @@ class YamlSymfonyTest extends YamlTestBase {
    *
    * @covers ::encode
    */
-  public function testObjectSupportDisabled() {
+  public function testEncodeObjectSupportDisabled() {
+    $this->expectDeprecation("Calling Drupal\Component\Serialization\YamlSymfony::encode() is deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. Use \Drupal\Component\Serialization\Yaml::encode() instead. See https://www.drupal.org/node/3415489");
     $this->expectException(InvalidDataTypeException::class);
     $this->expectExceptionMessage('Object support when dumping a YAML file has been disabled.');
     $object = new \stdClass();
@@ -80,4 +90,20 @@ class YamlSymfonyTest extends YamlTestBase {
     YamlSymfony::encode([$object]);
   }
 
+  /**
+   * Ensures that decoding PHP objects does not work in Symfony.
+   *
+   * @covers ::decode
+   */
+  public function testDecodeObjectSupportDisabled(): void {
+    $this->expectDeprecation("Calling Drupal\Component\Serialization\YamlSymfony::decode() is deprecated in drupal:10.3.0 and is removed from drupal:11.0.0. Use \Drupal\Component\Serialization\Yaml::decode() instead. See https://www.drupal.org/node/3415489");
+    $this->expectException(InvalidDataTypeException::class);
+    $this->expectExceptionMessageMatches('/^Object support when parsing a YAML file has been disabled/');
+    $yaml = <<<YAML
+    obj: !php/object "O:8:\"stdClass\":1:{s:3:\"foo\";s:3:\"bar\";}"
+    YAML;
+
+    YamlSymfony::decode($yaml);
+  }
+
 }

core/tests/Drupal/Tests/Component/Serialization/YamlTest.php

@@ -5,175 +5,94 @@ declare(strict_types=1);
 namespace Drupal\Tests\Component\Serialization;
 
 use Drupal\Component\Serialization\Exception\InvalidDataTypeException;
-use Drupal\Component\Serialization\SerializationInterface;
 use Drupal\Component\Serialization\Yaml;
-use Drupal\Component\Serialization\YamlPecl;
-use Drupal\Component\Serialization\YamlSymfony;
-use PHPUnit\Framework\TestCase;
 
 /**
- * @coversDefaultClass \Drupal\Component\Serialization\Yaml
+ * Tests the Yaml serialization implementation.
+ *
+ * @group Drupal
  * @group Serialization
+ * @coversDefaultClass \Drupal\Component\Serialization\Yaml
  */
-class YamlTest extends TestCase {
-
-  /**
-   * @var \PHPUnit\Framework\MockObject\MockObject
-   */
-  protected $mockParser;
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function setUp(): void {
-    parent::setUp();
-    $this->mockParser = $this->getMockBuilder('\stdClass')
-      ->addMethods(['encode', 'decode', 'getFileExtension'])
-      ->getMock();
-    YamlParserProxy::setMock($this->mockParser);
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function tearDown(): void {
-    YamlParserProxy::setMock(NULL);
-    parent::tearDown();
-  }
+class YamlTest extends YamlTestBase {
 
   /**
+   * Tests encoding and decoding basic data structures.
+   *
+   * @covers ::encode
    * @covers ::decode
+   * @dataProvider providerEncodeDecodeTests
    */
-  public function testDecode() {
-    $this->mockParser
-      ->expects($this->once())
-      ->method('decode');
-    YamlStub::decode('test');
+  public function testEncodeDecode($data) {
+    $this->assertSame($data, Yaml::decode(Yaml::encode($data)));
+  }
+
+  /**
+   * Tests decoding YAML node anchors.
+   *
+   * @covers ::decode
+   * @dataProvider providerDecodeTests
+   */
+  public function testDecode($string, $data) {
+    $this->assertSame($data, Yaml::decode($string));
+  }
+
+  /**
+   * Tests our encode settings.
+   *
+   * @covers ::encode
+   */
+  public function testEncode() {
+    // cSpell:disable
+    $this->assertSame('foo:
+  bar: \'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vivamus sapien ex, venenatis vitae nisi eu, posuere luctus dolor. Nullam convallis\'
+', Yaml::encode(['foo' => ['bar' => 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vivamus sapien ex, venenatis vitae nisi eu, posuere luctus dolor. Nullam convallis']]));
+    // cSpell:enable
   }
 
   /**
    * @covers ::getFileExtension
    */
   public function testGetFileExtension() {
-    $this->mockParser
-      ->expects($this->never())
-      ->method('getFileExtension');
-    $this->assertEquals('yml', YamlStub::getFileExtension());
+    $this->assertSame('yml', Yaml::getFileExtension());
   }
 
   /**
-   * Tests all YAML files are decoded in the same way with Symfony and PECL.
+   * Tests that invalid YAML throws an exception.
    *
-   * This test is a little bit slow but it tests that we do not have any bugs in
-   * our YAML that might not be decoded correctly in any of our implementations.
-   *
-   * @todo This should exist as an integration test not part of our unit tests.
-   *   https://www.drupal.org/node/2597730
-   *
-   * @requires extension yaml
-   * @dataProvider providerYamlFilesInCore
+   * @covers ::decode
    */
-  public function testYamlFiles($file) {
-    $data = file_get_contents($file);
-    try {
-      $this->assertEquals(YamlSymfony::decode($data), YamlPecl::decode($data), $file);
-    }
-    catch (InvalidDataTypeException $e) {
-      // Provide file context to the failure so the exception message is useful.
-      $this->fail("Exception thrown parsing $file:\n" . $e->getMessage());
-    }
+  public function testError() {
+    $this->expectException(InvalidDataTypeException::class);
+    Yaml::decode('foo: [ads');
   }
 
   /**
-   * Ensures that decoding php objects does not work in PECL.
+   * Ensures that php object support is disabled.
    *
-   * @requires extension yaml
-   *
-   * @see \Drupal\Tests\Component\Serialization\YamlTest::testObjectSupportDisabledSymfony()
+   * @covers ::encode
    */
-  public function testObjectSupportDisabledPecl() {
+  public function testEncodeObjectSupportDisabled() {
+    $this->expectException(InvalidDataTypeException::class);
+    $this->expectExceptionMessage('Object support when dumping a YAML file has been disabled.');
     $object = new \stdClass();
     $object->foo = 'bar';
-    // In core all Yaml encoding is done via Symfony and it does not support
-    // objects so in order to encode an object we have to use the PECL
-    // extension.
-    // @see \Drupal\Component\Serialization\Yaml::encode()
-    $yaml = YamlPecl::encode([$object]);
-    $this->assertEquals(['O:8:"stdClass":1:{s:3:"foo";s:3:"bar";}'], YamlPecl::decode($yaml));
+    Yaml::encode([$object]);
   }
 
   /**
-   * Ensures that decoding php objects does not work in Symfony.
+   * Ensures that decoding PHP objects does not work in Symfony.
    *
-   * @requires extension yaml
-   *
-   * @see \Drupal\Tests\Component\Serialization\YamlTest::testObjectSupportDisabledPecl()
+   * @covers ::decode
    */
-  public function testObjectSupportDisabledSymfony() {
+  public function testDecodeObjectSupportDisabled() {
     $this->expectException(InvalidDataTypeException::class);
     $this->expectExceptionMessageMatches('/^Object support when parsing a YAML file has been disabled/');
-    $object = new \stdClass();
-    $object->foo = 'bar';
-    // In core all Yaml encoding is done via Symfony and it does not support
-    // objects so in order to encode an object we have to use the PECL
-    // extension.
-    // @see \Drupal\Component\Serialization\Yaml::encode()
-    $yaml = YamlPecl::encode([$object]);
-    YamlSymfony::decode($yaml);
-  }
+    $yaml = <<<YAML
+    obj: !php/object "O:8:\"stdClass\":1:{s:3:\"foo\";s:3:\"bar\";}"
+    YAML;
 
-  /**
-   * Data provider that lists all YAML files in core.
-   */
-  public static function providerYamlFilesInCore() {
-    $files = [];
-    $dirs = new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator(__DIR__ . '/../../../../../', \RecursiveDirectoryIterator::FOLLOW_SYMLINKS));
-    foreach ($dirs as $dir) {
-      $pathname = $dir->getPathname();
-      // Exclude core/node_modules.
-      if ($dir->getExtension() == 'yml' && !str_contains($pathname, '/../../../../../node_modules')) {
-        if (str_contains($dir->getRealPath(), 'invalid_file')) {
-          // There are some intentionally invalid files provided for testing
-          // library API behaviors, ignore them.
-          continue;
-        }
-        $files[] = [$dir->getRealPath()];
-      }
-    }
-    return $files;
-  }
-
-}
-
-class YamlStub extends Yaml {
-
-  public static function getSerializer() {
-    return '\Drupal\Tests\Component\Serialization\YamlParserProxy';
-  }
-
-}
-
-class YamlParserProxy implements SerializationInterface {
-
-  /**
-   * @var \Drupal\Component\Serialization\SerializationInterface
-   */
-  protected static $mock;
-
-  public static function setMock($mock) {
-    static::$mock = $mock;
-  }
-
-  public static function encode($data) {
-    return static::$mock->encode($data);
-  }
-
-  public static function decode($raw) {
-    return static::$mock->decode($raw);
-  }
-
-  public static function getFileExtension() {
-    return static::$mock->getFileExtension();
+    Yaml::decode($yaml);
   }
 
 }

core/tests/Drupal/Tests/Composer/Plugin/Scaffold/fixtures/drupal-assets-fixture/assets/default.services.yml

@@ -1,4 +1 @@
 # Test version of default.services.yml from drupal/core.
-# Add a dummy key until YamlPecl can validate an empty YAML file:
-# https://www.drupal.org/project/drupal/issues/3003300
-foo: bar

core/tests/Drupal/Tests/Composer/Plugin/Scaffold/fixtures/drupal-profile/assets/profile.default.services.yml

@@ -1,4 +1 @@
 # default.services.yml fixture scaffolded from "file-mappings" in drupal-project composer.json fixture.
-# Add a dummy key until YamlPecl can validate an empty YAML file:
-# https://www.drupal.org/project/drupal/issues/3003300
-foo: bar

core/tests/Drupal/Tests/Core/Serialization/YamlTest.php

@@ -1,78 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Drupal\Tests\Core\Serialization;
-
-use Drupal\Component\Serialization\SerializationInterface;
-use Drupal\Core\Serialization\Yaml;
-use Drupal\Core\Site\Settings;
-use Drupal\Tests\UnitTestCase;
-
-/**
- * @coversDefaultClass \Drupal\Core\Serialization\Yaml
- * @group Serialization
- */
-class YamlTest extends UnitTestCase {
-
-  /**
-   * Tests that the overridden serializer is called.
-   *
-   * @covers ::getSerializer
-   * @runInSeparateProcess
-   */
-  public function testGetSerialization() {
-    new Settings(['yaml_parser_class' => YamlParserProxy::class]);
-
-    $this->assertEquals(YamlParserProxy::class, Settings::get('yaml_parser_class'));
-
-    $mock = $this->getMockBuilder(YamlTestMockInterface::class)
-      ->onlyMethods(['decode'])
-      ->getMock();
-    $mock
-      ->expects($this->once())
-      ->method('decode');
-    YamlParserProxy::setMock($mock);
-    Yaml::decode('---');
-
-    new Settings([]);
-  }
-
-}
-
-class YamlParserProxy implements SerializationInterface {
-
-  /**
-   * @var \Drupal\Component\Serialization\SerializationInterface
-   */
-  protected static $mock;
-
-  public static function setMock($mock) {
-    static::$mock = $mock;
-  }
-
-  public static function encode($data) {
-    return static::$mock->encode($data);
-  }
-
-  public static function decode($raw) {
-    return static::$mock->decode($raw);
-  }
-
-  public static function getFileExtension() {
-    return static::$mock->getFileExtension();
-  }
-
-}
-
-/**
- * Interface used in the mocking process of this test.
- */
-interface YamlTestMockInterface {
-
-  /**
-   * Function used in the mocking process of this test.
-   */
-  public function decode();
-
-}