Relax return types of getExceptionConverter() implementations (doctri…

…ne#6221)

|      Q       |   A
|------------- | -----------
| Type         | improvement
| Fixed issues | N/A

#### Summary

This takes back a change I made with doctrine#4926. If I want to implement a new
let's say MySQL driver that uses a custom exception converter, I'm
forced to extend the MySQL exception converter which feels too
restrictive.

Background: I maintain a custom ODBC driver for DBAL and since ODBC has
its own error codes, the MySQL exception converter is useless for me in
that context.

src/Driver/AbstractDB2Driver.php

@@ -5,6 +5,7 @@
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Driver;
+use Doctrine\DBAL\Driver\API\ExceptionConverter as ExceptionConverterInterface;
 use Doctrine\DBAL\Driver\API\IBMDB2\ExceptionConverter;
 use Doctrine\DBAL\Platforms\DB2Platform;
 use Doctrine\DBAL\ServerVersionProvider;
@@ -19,7 +20,7 @@ public function getDatabasePlatform(ServerVersionProvider $versionProvider): DB2
         return new DB2Platform();
     }
 
-    public function getExceptionConverter(): ExceptionConverter
+    public function getExceptionConverter(): ExceptionConverterInterface
     {
         return new ExceptionConverter();
     }

src/Driver/AbstractMySQLDriver.php

@@ -5,6 +5,7 @@
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Driver;
+use Doctrine\DBAL\Driver\API\ExceptionConverter as ExceptionConverterInterface;
 use Doctrine\DBAL\Driver\API\MySQL\ExceptionConverter;
 use Doctrine\DBAL\Platforms\AbstractMySQLPlatform;
 use Doctrine\DBAL\Platforms\Exception\InvalidPlatformVersion;
@@ -52,7 +53,7 @@ public function getDatabasePlatform(ServerVersionProvider $versionProvider): Abs
         return new MySQLPlatform();
     }
 
-    public function getExceptionConverter(): ExceptionConverter
+    public function getExceptionConverter(): ExceptionConverterInterface
     {
         return new ExceptionConverter();
     }

src/Driver/AbstractOracleDriver.php

@@ -6,6 +6,7 @@
 
 use Doctrine\DBAL\Driver;
 use Doctrine\DBAL\Driver\AbstractOracleDriver\EasyConnectString;
+use Doctrine\DBAL\Driver\API\ExceptionConverter as ExceptionConverterInterface;
 use Doctrine\DBAL\Driver\API\OCI\ExceptionConverter;
 use Doctrine\DBAL\Platforms\OraclePlatform;
 use Doctrine\DBAL\ServerVersionProvider;
@@ -20,7 +21,7 @@ public function getDatabasePlatform(ServerVersionProvider $versionProvider): Ora
         return new OraclePlatform();
     }
 
-    public function getExceptionConverter(): ExceptionConverter
+    public function getExceptionConverter(): ExceptionConverterInterface
     {
         return new ExceptionConverter();
     }

src/Driver/AbstractPostgreSQLDriver.php

@@ -5,6 +5,7 @@
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Driver;
+use Doctrine\DBAL\Driver\API\ExceptionConverter as ExceptionConverterInterface;
 use Doctrine\DBAL\Driver\API\PostgreSQL\ExceptionConverter;
 use Doctrine\DBAL\Platforms\PostgreSQLPlatform;
 use Doctrine\DBAL\ServerVersionProvider;
@@ -19,7 +20,7 @@ public function getDatabasePlatform(ServerVersionProvider $versionProvider): Pos
         return new PostgreSQLPlatform();
     }
 
-    public function getExceptionConverter(): ExceptionConverter
+    public function getExceptionConverter(): ExceptionConverterInterface
     {
         return new ExceptionConverter();
     }

src/Driver/AbstractSQLServerDriver.php

@@ -5,6 +5,7 @@
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Driver;
+use Doctrine\DBAL\Driver\API\ExceptionConverter as ExceptionConverterInterface;
 use Doctrine\DBAL\Driver\API\SQLSrv\ExceptionConverter;
 use Doctrine\DBAL\Platforms\SQLServerPlatform;
 use Doctrine\DBAL\ServerVersionProvider;
@@ -19,7 +20,7 @@ public function getDatabasePlatform(ServerVersionProvider $versionProvider): SQL
         return new SQLServerPlatform();
     }
 
-    public function getExceptionConverter(): ExceptionConverter
+    public function getExceptionConverter(): ExceptionConverterInterface
     {
         return new ExceptionConverter();
     }

src/Driver/AbstractSQLiteDriver.php

@@ -5,6 +5,7 @@
 namespace Doctrine\DBAL\Driver;
 
 use Doctrine\DBAL\Driver;
+use Doctrine\DBAL\Driver\API\ExceptionConverter as ExceptionConverterInterface;
 use Doctrine\DBAL\Driver\API\SQLite\ExceptionConverter;
 use Doctrine\DBAL\Platforms\SQLitePlatform;
 use Doctrine\DBAL\ServerVersionProvider;
@@ -19,7 +20,7 @@ public function getDatabasePlatform(ServerVersionProvider $versionProvider): SQL
         return new SQLitePlatform();
     }
 
-    public function getExceptionConverter(): ExceptionConverter
+    public function getExceptionConverter(): ExceptionConverterInterface
     {
         return new ExceptionConverter();
     }