minor #42165 Simplify some code with null coalesce operator (javiereguiluz)

This PR was squashed before being merged into the 4.4 branch.

Discussion
----------

Simplify some code with null coalesce operator

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Tickets       | -
| License       | MIT
| Doc PR        | -

For your consideration. There are many other possible usages of null coalesce operator, but the result is not very readable ... so this PR only contains the changes where the result is clearly better.

Commits
-------

17ad5b75fa Simplify some code with null coalesce operator

src/Symfony/Bridge/Doctrine/ContainerAwareEventManager.php

@@ -54,7 +54,7 @@ class ContainerAwareEventManager extends EventManager
             return;
         }
 
-        $eventArgs = null === $eventArgs ? EventArgs::getEmptyInstance() : $eventArgs;
+        $eventArgs = $eventArgs ?? EventArgs::getEmptyInstance();
 
         if (!isset($this->initialized[$eventName])) {
             $this->initializeListeners($eventName);

src/Symfony/Bridge/Doctrine/Validator/Constraints/UniqueEntityValidator.php

@@ -163,7 +163,7 @@ class UniqueEntityValidator extends ConstraintValidator
             return;
         }
 
-        $errorPath = null !== $constraint->errorPath ? $constraint->errorPath : $fields[0];
+        $errorPath = $constraint->errorPath ?? $fields[0];
         $invalidValue = $criteria[$errorPath] ?? $criteria[$fields[0]];
 
         $this->context->buildViolation($constraint->message)

src/Symfony/Bundle/FrameworkBundle/Command/AssetsInstallCommand.php

@@ -278,10 +278,6 @@ EOT
 
         $composerConfig = json_decode(file_get_contents($composerFilePath), true);
 
-        if (isset($composerConfig['extra']['public-dir'])) {
-            return $composerConfig['extra']['public-dir'];
-        }
-
-        return $defaultPublicDir;
+        return $composerConfig['extra']['public-dir'] ?? $defaultPublicDir;
     }
 }

src/Symfony/Bundle/FrameworkBundle/Console/Descriptor/JsonDescriptor.php

@@ -134,7 +134,7 @@ class JsonDescriptor extends Descriptor
 
     protected function describeEventDispatcherListeners(EventDispatcherInterface $eventDispatcher, array $options = [])
     {
-        $this->writeData($this->getEventDispatcherListenersData($eventDispatcher, \array_key_exists('event', $options) ? $options['event'] : null), $options);
+        $this->writeData($this->getEventDispatcherListenersData($eventDispatcher, $options['event'] ?? null), $options);
     }
 
     protected function describeCallable($callable, array $options = [])

src/Symfony/Bundle/FrameworkBundle/Console/Descriptor/MarkdownDescriptor.php

@@ -258,7 +258,7 @@ class MarkdownDescriptor extends Descriptor
 
     protected function describeEventDispatcherListeners(EventDispatcherInterface $eventDispatcher, array $options = [])
     {
-        $event = \array_key_exists('event', $options) ? $options['event'] : null;
+        $event = $options['event'] ?? null;
 
         $title = 'Registered listeners';
         if (null !== $event) {

src/Symfony/Bundle/FrameworkBundle/Console/Descriptor/TextDescriptor.php

@@ -442,7 +442,7 @@ class TextDescriptor extends Descriptor
 
     protected function describeEventDispatcherListeners(EventDispatcherInterface $eventDispatcher, array $options = [])
     {
-        $event = \array_key_exists('event', $options) ? $options['event'] : null;
+        $event = $options['event'] ?? null;
 
         if (null !== $event) {
             $title = sprintf('Registered Listeners for "%s" Event', $event);

src/Symfony/Bundle/FrameworkBundle/Console/Descriptor/XmlDescriptor.php

@@ -88,7 +88,7 @@ class XmlDescriptor extends Descriptor
 
     protected function describeEventDispatcherListeners(EventDispatcherInterface $eventDispatcher, array $options = [])
     {
-        $this->writeDocument($this->getEventDispatcherListenersDocument($eventDispatcher, \array_key_exists('event', $options) ? $options['event'] : null));
+        $this->writeDocument($this->getEventDispatcherListenersDocument($eventDispatcher, $options['event'] ?? null));
     }
 
     protected function describeCallable($callable, array $options = [])

src/Symfony/Bundle/FrameworkBundle/Controller/ControllerTrait.php

@@ -144,7 +144,7 @@ trait ControllerTrait
     protected function file($file, string $fileName = null, string $disposition = ResponseHeaderBag::DISPOSITION_ATTACHMENT): BinaryFileResponse
     {
         $response = new BinaryFileResponse($file);
-        $response->setContentDisposition($disposition, null === $fileName ? $response->getFile()->getFilename() : $fileName);
+        $response->setContentDisposition($disposition, $fileName ?? $response->getFile()->getFilename());
 
         return $response;
     }

src/Symfony/Component/Cache/Adapter/ArrayAdapter.php

@@ -141,7 +141,7 @@ class ArrayAdapter implements AdapterInterface, CacheInterface, LoggerAwareInter
         }
 
         $this->values[$key] = $value;
-        $this->expiries[$key] = null !== $expiry ? $expiry : \PHP_INT_MAX;
+        $this->expiries[$key] = $expiry ?? \PHP_INT_MAX;
 
         return true;
     }

src/Symfony/Component/Cache/Traits/RedisTrait.php

@@ -172,7 +172,7 @@ trait RedisTrait
         if (null === $params['class'] && !isset($params['redis_sentinel']) && \extension_loaded('redis')) {
             $class = $params['redis_cluster'] ? \RedisCluster::class : (1 < \count($hosts) ? \RedisArray::class : \Redis::class);
         } else {
-            $class = null === $params['class'] ? \Predis\Client::class : $params['class'];
+            $class = $params['class'] ?? \Predis\Client::class;
         }
 
         if (is_a($class, \Redis::class, true)) {

src/Symfony/Component/Console/Event/ConsoleErrorEvent.php

@@ -53,6 +53,6 @@ final class ConsoleErrorEvent extends ConsoleEvent
 
     public function getExitCode(): int
     {
-        return null !== $this->exitCode ? $this->exitCode : (\is_int($this->error->getCode()) && 0 !== $this->error->getCode() ? $this->error->getCode() : 1);
+        return $this->exitCode ?? (\is_int($this->error->getCode()) && 0 !== $this->error->getCode() ? $this->error->getCode() : 1);
     }
 }

src/Symfony/Component/DependencyInjection/Compiler/MergeExtensionConfigurationPass.php

@@ -143,7 +143,7 @@ class MergeExtensionConfigurationParameterBag extends EnvPlaceholderParameterBag
      */
     public function getEnvPlaceholders(): array
     {
-        return null !== $this->processedEnvPlaceholders ? $this->processedEnvPlaceholders : parent::getEnvPlaceholders();
+        return $this->processedEnvPlaceholders ?? parent::getEnvPlaceholders();
     }
 
     public function getUnusedEnvPlaceholders(): array

src/Symfony/Component/DependencyInjection/ContainerBuilder.php

@@ -1630,7 +1630,7 @@ class ContainerBuilder extends Container implements TaggedContainerInterface
      */
     private function shareService(Definition $definition, $service, ?string $id, array &$inlineServices)
     {
-        $inlineServices[null !== $id ? $id : spl_object_hash($definition)] = $service;
+        $inlineServices[$id ?? spl_object_hash($definition)] = $service;
 
         if (null !== $id && $definition->isShared()) {
             $this->services[$id] = $service;

src/Symfony/Component/Form/Extension/Core/DataTransformer/IntegerToLocalizedStringTransformer.php

@@ -34,7 +34,7 @@ class IntegerToLocalizedStringTransformer extends NumberToLocalizedStringTransfo
             @trigger_error(sprintf('Passing a precision as the first value to %s::__construct() is deprecated since Symfony 4.2 and support for it will be dropped in 5.0.', __CLASS__), \E_USER_DEPRECATED);
 
             $grouping = $roundingMode;
-            $roundingMode = null !== $locale ? $locale : self::ROUND_DOWN;
+            $roundingMode = $locale ?? self::ROUND_DOWN;
             $locale = null;
         }
 

src/Symfony/Component/Form/Extension/Core/Type/TextType.php

@@ -62,6 +62,6 @@ class TextType extends AbstractType implements DataTransformerInterface
      */
     public function reverseTransform($data)
     {
-        return null === $data ? '' : $data;
+        return $data ?? '';
     }
 }

src/Symfony/Component/HttpFoundation/Request.php

@@ -1371,7 +1371,7 @@ class Request
             $this->format = $this->attributes->get('_format');
         }
 
-        return null === $this->format ? $default : $this->format;
+        return $this->format ?? $default;
     }
 
     /**

src/Symfony/Component/HttpFoundation/RequestStack.php

@@ -94,10 +94,6 @@ class RequestStack
     {
         $pos = \count($this->requests) - 2;
 
-        if (!isset($this->requests[$pos])) {
-            return null;
-        }
-
-        return $this->requests[$pos];
+        return $this->requests[$pos] ?? null;
     }
 }

src/Symfony/Component/HttpFoundation/ResponseHeaderBag.php

@@ -176,7 +176,7 @@ class ResponseHeaderBag extends HeaderBag
      */
     public function getCacheControlDirective($key)
     {
-        return \array_key_exists($key, $this->computedCacheControl) ? $this->computedCacheControl[$key] : null;
+        return $this->computedCacheControl[$key] ?? null;
     }
 
     public function setCookie(Cookie $cookie)

src/Symfony/Component/HttpFoundation/Session/Storage/MetadataBag.php

@@ -163,6 +163,6 @@ class MetadataBag implements SessionBagInterface
     {
         $timeStamp = time();
         $this->meta[self::CREATED] = $this->meta[self::UPDATED] = $this->lastUsed = $timeStamp;
-        $this->meta[self::LIFETIME] = (null === $lifetime) ? ini_get('session.cookie_lifetime') : $lifetime;
+        $this->meta[self::LIFETIME] = $lifetime ?? ini_get('session.cookie_lifetime');
     }
 }

src/Symfony/Component/HttpKernel/EventListener/DebugHandlersListener.php

@@ -60,7 +60,7 @@ class DebugHandlersListener implements EventSubscriberInterface
 
         $this->exceptionHandler = $exceptionHandler;
         $this->logger = $logger;
-        $this->levels = null === $levels ? \E_ALL : $levels;
+        $this->levels = $levels ?? \E_ALL;
         $this->throwAt = \is_int($throwAt) ? $throwAt : (null === $throwAt ? null : ($throwAt ? \E_ALL : null));
         $this->scream = $scream;
         $this->fileLinkFormat = $fileLinkFormat;

src/Symfony/Component/HttpKernel/Profiler/Profile.php

@@ -156,11 +156,7 @@ class Profile
      */
     public function getTime()
     {
-        if (null === $this->time) {
-            return 0;
-        }
-
-        return $this->time;
+        return $this->time ?? 0;
     }
 
     /**

src/Symfony/Component/HttpKernel/Tests/KernelTest.php

@@ -709,7 +709,7 @@ EOF
         $bundle
             ->expects($this->any())
             ->method('getName')
-            ->willReturn(null === $bundleName ? \get_class($bundle) : $bundleName)
+            ->willReturn($bundleName ?? \get_class($bundle))
         ;
 
         $bundle

src/Symfony/Component/Intl/DateFormatter/IntlDateFormatter.php

@@ -142,8 +142,8 @@ abstract class IntlDateFormatter
             throw new MethodArgumentValueNotImplementedException(__METHOD__, 'calendar', $calendar, 'Only the GREGORIAN calendar is supported');
         }
 
-        $this->datetype = null !== $datetype ? $datetype : self::FULL;
-        $this->timetype = null !== $timetype ? $timetype : self::FULL;
+        $this->datetype = $datetype ?? self::FULL;
+        $this->timetype = $timetype ?? self::FULL;
 
         if ('' === ($pattern ?? '')) {
             $pattern = $this->getDefaultPattern();

src/Symfony/Component/Intl/Tests/DateFormatter/AbstractIntlDateFormatterTest.php

@@ -933,7 +933,7 @@ abstract class AbstractIntlDateFormatterTest extends TestCase
     protected function getDateTime($timestamp, $timeZone)
     {
         $dateTime = new \DateTime();
-        $dateTime->setTimestamp(null === $timestamp ? time() : $timestamp);
+        $dateTime->setTimestamp($timestamp ?? time());
         $dateTime->setTimezone(new \DateTimeZone($timeZone ?: getenv('TZ') ?: 'UTC'));
 
         return $dateTime;

src/Symfony/Component/Intl/Util/GitRepository.php

@@ -95,7 +95,7 @@ final class GitRepository
         exec(sprintf('%s 2>&1', $command), $output, $result);
 
         if (0 !== $result) {
-            throw new RuntimeException(null !== $customErrorMessage ? $customErrorMessage : sprintf('The "%s" command failed.', $command));
+            throw new RuntimeException($customErrorMessage ?? sprintf('The "%s" command failed.', $command));
         }
 
         return $output;

src/Symfony/Component/Messenger/Tests/WorkerTest.php

@@ -260,7 +260,7 @@ class DummyReceiver implements ReceiverInterface
     {
         $val = array_shift($this->deliveriesOfEnvelopes);
 
-        return null === $val ? [] : $val;
+        return $val ?? [];
     }
 
     public function ack(Envelope $envelope): void

src/Symfony/Component/PropertyInfo/Extractor/PhpDocExtractor.php

@@ -66,9 +66,9 @@ class PhpDocExtractor implements PropertyDescriptionExtractorInterface, Property
         $this->docBlockFactory = $docBlockFactory ?: DocBlockFactory::createInstance();
         $this->contextFactory = new ContextFactory();
         $this->phpDocTypeHelper = new PhpDocTypeHelper();
-        $this->mutatorPrefixes = null !== $mutatorPrefixes ? $mutatorPrefixes : ReflectionExtractor::$defaultMutatorPrefixes;
-        $this->accessorPrefixes = null !== $accessorPrefixes ? $accessorPrefixes : ReflectionExtractor::$defaultAccessorPrefixes;
-        $this->arrayMutatorPrefixes = null !== $arrayMutatorPrefixes ? $arrayMutatorPrefixes : ReflectionExtractor::$defaultArrayMutatorPrefixes;
+        $this->mutatorPrefixes = $mutatorPrefixes ?? ReflectionExtractor::$defaultMutatorPrefixes;
+        $this->accessorPrefixes = $accessorPrefixes ?? ReflectionExtractor::$defaultAccessorPrefixes;
+        $this->arrayMutatorPrefixes = $arrayMutatorPrefixes ?? ReflectionExtractor::$defaultArrayMutatorPrefixes;
     }
 
     /**

src/Symfony/Component/PropertyInfo/Extractor/ReflectionExtractor.php

@@ -68,9 +68,9 @@ class ReflectionExtractor implements PropertyListExtractorInterface, PropertyTyp
      */
     public function __construct(array $mutatorPrefixes = null, array $accessorPrefixes = null, array $arrayMutatorPrefixes = null, bool $enableConstructorExtraction = true, int $accessFlags = self::ALLOW_PUBLIC)
     {
-        $this->mutatorPrefixes = null !== $mutatorPrefixes ? $mutatorPrefixes : self::$defaultMutatorPrefixes;
-        $this->accessorPrefixes = null !== $accessorPrefixes ? $accessorPrefixes : self::$defaultAccessorPrefixes;
-        $this->arrayMutatorPrefixes = null !== $arrayMutatorPrefixes ? $arrayMutatorPrefixes : self::$defaultArrayMutatorPrefixes;
+        $this->mutatorPrefixes = $mutatorPrefixes ?? self::$defaultMutatorPrefixes;
+        $this->accessorPrefixes = $accessorPrefixes ?? self::$defaultAccessorPrefixes;
+        $this->arrayMutatorPrefixes = $arrayMutatorPrefixes ?? self::$defaultArrayMutatorPrefixes;
         $this->enableConstructorExtraction = $enableConstructorExtraction;
         $this->accessFlags = $accessFlags;
 

src/Symfony/Component/Security/Http/Firewall/RememberMeListener.php

@@ -58,7 +58,7 @@ class RememberMeListener extends AbstractListener implements ListenerInterface
         }
 
         $this->catchExceptions = $catchExceptions;
-        $this->sessionStrategy = null === $sessionStrategy ? new SessionAuthenticationStrategy(SessionAuthenticationStrategy::MIGRATE) : $sessionStrategy;
+        $this->sessionStrategy = $sessionStrategy ?? new SessionAuthenticationStrategy(SessionAuthenticationStrategy::MIGRATE);
     }
 
     /**

src/Symfony/Component/Security/Http/Tests/Firewall/ExceptionListenerTest.php

@@ -99,7 +99,7 @@ class ExceptionListenerTest extends TestCase
         $listener->onKernelException($event);
 
         $this->assertNull($event->getResponse());
-        $this->assertSame(null === $eventException ? $exception : $eventException, $event->getThrowable()->getPrevious());
+        $this->assertSame($eventException ?? $exception, $event->getThrowable()->getPrevious());
     }
 
     /**
@@ -122,7 +122,7 @@ class ExceptionListenerTest extends TestCase
 
         $this->assertEquals('Unauthorized', $event->getResponse()->getContent());
         $this->assertEquals(401, $event->getResponse()->getStatusCode());
-        $this->assertSame(null === $eventException ? $exception : $eventException, $event->getThrowable()->getPrevious());
+        $this->assertSame($eventException ?? $exception, $event->getThrowable()->getPrevious());
     }
 
     /**
@@ -139,7 +139,7 @@ class ExceptionListenerTest extends TestCase
         $listener->onKernelException($event);
 
         $this->assertEquals('error', $event->getResponse()->getContent());
-        $this->assertSame(null === $eventException ? $exception : $eventException, $event->getThrowable()->getPrevious());
+        $this->assertSame($eventException ?? $exception, $event->getThrowable()->getPrevious());
     }
 
     /**
@@ -156,7 +156,7 @@ class ExceptionListenerTest extends TestCase
         $listener->onKernelException($event);
 
         $this->assertEquals('OK', $event->getResponse()->getContent());
-        $this->assertSame(null === $eventException ? $exception : $eventException, $event->getThrowable()->getPrevious());
+        $this->assertSame($eventException ?? $exception, $event->getThrowable()->getPrevious());
     }
 
     public function testLogoutException()

src/Symfony/Component/Validator/Constraints/File.php

@@ -112,10 +112,10 @@ class File extends Constraint
         ];
         if (ctype_digit((string) $maxSize)) {
             $this->maxSize = (int) $maxSize;
-            $this->binaryFormat = null === $this->binaryFormat ? false : $this->binaryFormat;
+            $this->binaryFormat = $this->binaryFormat ?? false;
         } elseif (preg_match('/^(\d++)('.implode('|', array_keys($factors)).')$/i', $maxSize, $matches)) {
             $this->maxSize = $matches[1] * $factors[$unit = strtolower($matches[2])];
-            $this->binaryFormat = null === $this->binaryFormat ? 2 === \strlen($unit) : $this->binaryFormat;
+            $this->binaryFormat = $this->binaryFormat ?? (2 === \strlen($unit));
         } else {
             throw new ConstraintDefinitionException(sprintf('"%s" is not a valid maximum size.', $this->maxSize));
         }

src/Symfony/Component/Validator/Constraints/FileValidator.php

@@ -60,7 +60,7 @@ class FileValidator extends ConstraintValidator
                         $binaryFormat = $constraint->binaryFormat;
                     } else {
                         $limitInBytes = $iniLimitSize;
-                        $binaryFormat = null === $constraint->binaryFormat ? true : $constraint->binaryFormat;
+                        $binaryFormat = $constraint->binaryFormat ?? true;
                     }
 
                     [, $limitAsString, $suffix] = $this->factorizeSizes(0, $limitInBytes, $binaryFormat);

src/Symfony/Component/Validator/Mapping/ClassMetadata.php

@@ -365,11 +365,7 @@ class ClassMetadata extends GenericMetadata implements ClassMetadataInterface
      */
     public function getPropertyMetadata($property)
     {
-        if (!isset($this->members[$property])) {
-            return [];
-        }
-
-        return $this->members[$property];
+        return $this->members[$property] ?? [];
     }
 
     /**

src/Symfony/Component/VarDumper/Dumper/AbstractDumper.php

@@ -63,7 +63,7 @@ abstract class AbstractDumper implements DataDumperInterface, DumperInterface
      */
     public function setOutput($output)
     {
-        $prev = null !== $this->outputStream ? $this->outputStream : $this->lineDumper;
+        $prev = $this->outputStream ?? $this->lineDumper;
 
         if (\is_callable($output)) {
             $this->outputStream = null;

src/Symfony/Component/VarDumper/Dumper/HtmlDumper.php

@@ -153,7 +153,7 @@ class HtmlDumper extends CliDumper
      */
     protected function getDumpHeader()
     {
-        $this->headerIsDumped = null !== $this->outputStream ? $this->outputStream : $this->lineDumper;
+        $this->headerIsDumped = $this->outputStream ?? $this->lineDumper;
 
         if (null !== $this->dumpHeader) {
             return $this->dumpHeader;
@@ -964,7 +964,7 @@ EOHTML
         if (-1 === $this->lastDepth) {
             $this->line = sprintf($this->dumpPrefix, $this->dumpId, $this->indentPad).$this->line;
         }
-        if ($this->headerIsDumped !== (null !== $this->outputStream ? $this->outputStream : $this->lineDumper)) {
+        if ($this->headerIsDumped !== ($this->outputStream ?? $this->lineDumper)) {
             $this->line = $this->getDumpHeader().$this->line;
         }