Generalize CustomIntrospectionTest (#6210)

|      Q       |   A
|------------- | -----------
| Type         | improvement
| Fixed issues | Follows #6189

#### Summary

This PR improves the test added in #6189 by allowing it to run on other
platforms than MySQL/MariaDB and by using non-deprecated APIs only. This
should make it easier to merge this test and later changes to it up to
the 4.0.x branch.

I've skipped Oracle though because I currently don't have a local Oracle
setup to test against.

tests/Functional/Schema/CustomIntrospectionTest.php

@@ -4,13 +4,11 @@
 
 namespace Doctrine\DBAL\Tests\Functional\Schema;
 
-use Doctrine\DBAL\Platforms\AbstractMySQLPlatform;
-use Doctrine\DBAL\Platforms\AbstractPlatform;
-use Doctrine\DBAL\Schema\AbstractSchemaManager;
-use Doctrine\DBAL\Schema\Comparator;
-use Doctrine\DBAL\Schema\Table;
+use Doctrine\DBAL\Schema\ColumnDiff;
+use Doctrine\DBAL\Schema\Schema;
 use Doctrine\DBAL\Tests\Functional\Schema\Types\MoneyType;
 use Doctrine\DBAL\Tests\FunctionalTestCase;
+use Doctrine\DBAL\Tests\TestUtil;
 use Doctrine\DBAL\Types\Type;
 
 use function array_map;
@@ -25,33 +23,21 @@
  */
 class CustomIntrospectionTest extends FunctionalTestCase
 {
-    private AbstractSchemaManager $schemaManager;
-
-    private Comparator $comparator;
-
-    private AbstractPlatform $platform;
-
     public static function setUpBeforeClass(): void
     {
-        Type::addType('money', MoneyType::class);
-    }
-
-    protected function setUp(): void
-    {
-        $this->platform = $this->connection->getDatabasePlatform();
-
-        if (! $this->platform instanceof AbstractMySQLPlatform) {
-            self::markTestSkipped();
+        if (TestUtil::isDriverOneOf('oci8', 'pdo_oci')) {
+            self::markTestSkipped('Skip on Oracle');
         }
 
-        $this->schemaManager = $this->connection->createSchemaManager();
-        $this->comparator    = $this->schemaManager->createComparator();
+        Type::addType('money', MoneyType::class);
     }
 
     public function testCustomColumnIntrospection(): void
     {
-        $tableName = 'test_custom_column_introspection';
-        $table     = new Table($tableName);
+        $tableName     = 'test_custom_column_introspection';
+        $schemaManager = $this->connection->createSchemaManager();
+        $schema        = new Schema([], [], $schemaManager->createSchemaConfig());
+        $table         = $schema->createTable($tableName);
 
         $table->addColumn('id', 'integer');
         $table->addColumn('quantity', 'decimal');
@@ -63,18 +49,20 @@ public function testCustomColumnIntrospection(): void
 
         $this->dropAndCreateTable($table);
 
-        $onlineTable = $this->schemaManager->introspectTable($tableName);
+        $onlineTable = $schemaManager->introspectTable($tableName);
+        $diff        = $schemaManager->createComparator()->compareTables($onlineTable, $table);
+        $changedCols = array_map(
+            static function (ColumnDiff $columnDiff): ?string {
+                $column = $columnDiff->getOldColumn();
 
-        $diff        = $this->comparator->compareTables($table, $onlineTable);
-        $changedCols = [];
-
-        if (! $diff->isEmpty()) {
-            $changedCols = array_map(static fn ($c) => $c->getOldColumnName()->getName(), $diff->getModifiedColumns());
-        }
+                return $column !== null ? $column->getName() : null;
+            },
+            $diff->getModifiedColumns(),
+        );
 
         self::assertTrue($diff->isEmpty(), sprintf(
             'Tables should be identical. Differences detected in %s.',
-            implode(':', $changedCols),
+            implode(', ', $changedCols),
         ));
     }
 }