fix(MySQL): add an auto-increment column together with its index

src/Driver/MySQL/MySQLHandler.php

@@ -19,6 +19,7 @@
 use Cycle\Database\Schema\AbstractForeignKey;
 use Cycle\Database\Schema\AbstractIndex;
 use Cycle\Database\Schema\AbstractTable;
+use Cycle\Database\Schema\ComparatorInterface;
 
 class MySQLHandler extends Handler
 {
@@ -158,19 +159,53 @@ protected function createStatement(AbstractTable $table): string
         return $statement . " ENGINE {$table->getEngine()}";
     }
 
+    #[\Override]
+    protected function createColumns(AbstractTable $table, ComparatorInterface $comparator): void
+    {
+        foreach ($comparator->addedColumns() as $column) {
+            $this->assertValid($column);
+
+            // MySQL rejects an AUTO_INCREMENT column without a key, so its index is added in the same statement.
+            $statement = "ALTER TABLE {$this->identify($table)} ADD COLUMN {$column->sqlStatement($this->getDriver())}";
+            foreach ($this->autoIncrementIndexes($table, [$column], $comparator->addedIndexes()) as $index) {
+                $statement .= ", ADD {$index->sqlStatement($this->getDriver(), false)}";
+            }
+
+            $this->run($statement);
+        }
+    }
+
+    #[\Override]
+    protected function createIndexes(AbstractTable $table, ComparatorInterface $comparator): void
+    {
+        $created = $this->autoIncrementIndexes($table, $comparator->addedColumns(), $comparator->addedIndexes());
+        foreach ($comparator->addedIndexes() as $index) {
+            if (!\in_array($index, $created, true)) {
+                $this->createIndex($table, $index);
+            }
+        }
+    }
+
     /**
      * Indexes covering AUTO_INCREMENT columns that do not lead the primary key.
      *
+     * @param AbstractColumn[]|null $columns Columns to check, all table columns by default.
+     * @param AbstractIndex[]|null $indexes Indexes to search, all table indexes by default.
+     *
      * @return list<AbstractIndex>
      *
      * @throws SchemaException When such a column is neither in the primary key nor in an index.
      */
-    protected function autoIncrementIndexes(AbstractTable $table): array
-    {
+    protected function autoIncrementIndexes(
+        AbstractTable $table,
+        ?array $columns = null,
+        ?array $indexes = null,
+    ): array {
         $primaryKeys = $table->getPrimaryKeys();
+        $indexes ??= $table->getIndexes();
 
         $result = [];
-        foreach ($table->getColumns() as $column) {
+        foreach ($columns ?? $table->getColumns() as $column) {
             if (
                 ($column->getAttributes()['autoIncrement'] ?? false) !== true
                 || ($primaryKeys[0] ?? null) === $column->getName()
@@ -179,7 +214,7 @@ protected function autoIncrementIndexes(AbstractTable $table): array
             }
 
             $found = \in_array($column->getName(), $primaryKeys, true);
-            foreach ($table->getIndexes() as $index) {
+            foreach ($indexes as $index) {
                 if (\in_array($column->getName(), $index->getColumns(), true)) {
                     $found = true;
                     \in_array($index, $result, true) or $result[] = $index;

tests/Database/Functional/Driver/MySQL/Schema/AutoIncrementColumnTest.php

@@ -23,6 +23,12 @@ public static function primaryTypesProvider(): iterable
         yield 'bigPrimary' => ['bigPrimary', 'bigPrimary'];
     }
 
+    public static function addedIndexProvider(): iterable
+    {
+        yield 'unique index' => [true];
+        yield 'index' => [false];
+    }
+
     public function testAutoIncrementColumnIsNotAddedToPrimaryKey(): void
     {
         $schema = $this->schema('auto_increment');
@@ -101,6 +107,63 @@ public function testAutoIncrementColumnWithoutKeyThrowsException(): void
         $schema->save();
     }
 
+    /**
+     * @dataProvider addedIndexProvider
+     */
+    public function testAddAutoIncrementColumnToExistingTable(bool $unique): void
+    {
+        $schema = $this->schema('auto_increment');
+        $schema->string('id', 36)->nullable(false);
+        $schema->string('title')->nullable(true);
+        $schema->setPrimaryKeys(['id']);
+        $schema->index(['title']);
+        $schema->save();
+
+        $table = $this->database->table('auto_increment');
+        $table->insertOne(['id' => 'a', 'title' => 'first']);
+        $table->insertOne(['id' => 'b', 'title' => 'second']);
+
+        $schema = $this->schema('auto_increment');
+        $schema->integer('number', autoIncrement: true)->nullable(false);
+        $schema->index(['number'])->unique($unique);
+        $schema->string('note')->nullable(true);
+        $schema->index(['note']);
+        $schema->save();
+
+        $this->assertSameAsInDB($schema);
+
+        $saved = $this->schema('auto_increment');
+        $this->assertSame(['id'], $saved->getPrimaryKeys());
+        $this->assertTrue($saved->hasIndex(['number']));
+        $this->assertTrue($saved->hasIndex(['note']));
+
+        $table->insertOne(['id' => 'c', 'title' => 'third']);
+        $this->assertSame(
+            [['id' => 'a', 'number' => 1], ['id' => 'b', 'number' => 2], ['id' => 'c', 'number' => 3]],
+            $table->select('id', 'number')->orderBy('id')->fetchAll(),
+        );
+    }
+
+    public function testAddAutoIncrementColumnWithoutKeyThrowsException(): void
+    {
+        $schema = $this->schema('auto_increment');
+        $schema->string('id', 36)->nullable(false);
+        $schema->setPrimaryKeys(['id']);
+        $schema->save();
+
+        $schema = $this->schema('auto_increment');
+        $schema->integer('number', autoIncrement: true)->nullable(false);
+
+        try {
+            $schema->save();
+            $this->fail('SchemaException expected');
+        } catch (SchemaException $e) {
+            $this->assertStringContainsString('`number`', $e->getMessage());
+        }
+
+        $this->assertFalse($this->schema('auto_increment')->hasColumn('number'));
+    }
+
     public function testExistingTableIsReflectedWithItsPrimaryKey(): void
     {
         $this->database->execute(