Use the ?? feature instead of isset() where it makes sense

Change-Id: I3a54f36b33d99ef3ff4c63e32e7dfcbcfc296135

includes/ActorMigration.php

@@ -136,11 +136,7 @@ class ActorMigration {
 	 * @return string[] [ $text, $actor ]
 	 */
 	private static function getFieldNames( $key ) {
-		if ( isset( self::$specialFields[$key] ) ) {
-			return self::$specialFields[$key];
-		}
-
-		return [ $key . '_text', substr( $key, 0, -5 ) . '_actor' ];
+		return self::$specialFields[$key] ?? [ $key . '_text', substr( $key, 0, -5 ) . '_actor' ];
 	}
 
 	/**

includes/MagicWordArray.php

@@ -268,10 +268,7 @@ class MagicWordArray {
 			return $hash[1][$text];
 		}
 		$lc = $this->factory->getContentLanguage()->lc( $text );
-		if ( isset( $hash[0][$lc] ) ) {
-			return $hash[0][$lc];
-		}
-		return false;
+		return $hash[0][$lc] ?? false;
 	}
 
 	/**

includes/api/ApiFormatBase.php

@@ -158,11 +158,9 @@ abstract class ApiFormatBase extends ApiBase {
 
 		if ( !is_array( $paramSettings ) ) {
 			return $paramSettings;
-		} elseif ( isset( $paramSettings[self::PARAM_DFLT] ) ) {
-			return $paramSettings[self::PARAM_DFLT];
-		} else {
-			return null;
 		}
+
+		return $paramSettings[self::PARAM_DFLT] ?? null;
 	}
 
 	/**

includes/config/ConfigRepository.php

@@ -71,10 +71,8 @@ class ConfigRepository implements SalvageableService {
 		if ( !$this->has( $name, true ) ) {
 			throw new \ConfigException( 'The configuration option ' . $name . ' does not exist.' );
 		}
-		if ( isset( $this->configItems['public'][$name] ) ) {
-			return $this->configItems['public'][$name];
-		}
-		return $this->configItems['private'][$name];
+
+		return $this->configItems['public'][$name] ?? $this->configItems['private'][$name];
 	}
 
 	/**

includes/filerepo/file/ForeignAPIFile.php

@@ -184,11 +184,7 @@ class ForeignAPIFile extends File {
 	 *   null on error
 	 */
 	public function getExtendedMetadata() {
-		if ( isset( $this->mInfo['extmetadata'] ) ) {
-			return $this->mInfo['extmetadata'];
-		}
-
-		return null;
+		return $this->mInfo['extmetadata'] ?? null;
 	}
 
 	/**

includes/media/MediaHandlerFactory.php

@@ -66,11 +66,7 @@ class MediaHandlerFactory {
 	}
 
 	protected function getHandlerClass( $type ) {
-		if ( isset( $this->registry[$type] ) ) {
-			return $this->registry[$type];
-		} else {
-			return false;
-		}
+		return $this->registry[$type] ?? false;
 	}
 
 	/**

tests/parser/ParserTestRunner.php

@@ -938,12 +938,7 @@ class ParserTestRunner {
 	 */
 	private static function getOptionValue( $key, $opts, $default ) {
 		$key = strtolower( $key );
-
-		if ( isset( $opts[$key] ) ) {
-			return $opts[$key];
-		} else {
-			return $default;
-		}
+		return $opts[$key] ?? $default;
 	}
 
 	/**