Laravel migrate mysql database to utfmb4

2016_01_01_200328_migrate_to_utf8mb4.php

<?php

use Illuminate\Database\Migrations\Migration;

class MigrateToUtf8mb4 extends Migration
{

    public function up()
    {
        DB::statement('SET FOREIGN_KEY_CHECKS=0;');

        $connection = Schema::getConnection();

        $schema = $connection->getDoctrineSchemaManager();
        $tables = $schema->listTableNames();

        $platform = $connection->getDoctrineSchemaManager()->getDatabasePlatform();
        $platform->registerDoctrineTypeMapping('enum', 'string');

        foreach ($tables as $table) {
            try {
                $table = (array) $table;
                $table = array_values($table)[0];

                $columns = $schema->listTableColumns($table);
                $indexes = $schema->listTableIndexes($table);

                foreach ($columns as $column) {
                    if ($column->getType()->getName() == 'string' && $column->getLength() == '255') {
                        foreach ($indexes as $index) {
                            if (in_array($column->getName(), $index->getColumns())) {
                                DB::statement(sprintf('ALTER TABLE `%s` CHANGE `%s` `%s` VARCHAR(191);', $table, $column->getName(), $column->getName()));
                                break;
                            }
                        }
                    }
                }

                DB::statement(sprintf('ALTER TABLE `%s` CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;', $table));

                foreach ($columns as $column) {
                    if ($column->getType()->getName() == 'string' && $column->getType()->getName() == 'text') {
                        $type = $column->getType()->getName() == 'string' ? 'VARCHAR' : 'TEXT';
                        DB::statement(sprintf('ALTER TABLE `%s` CHANGE `%s` `%s` `%s` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;', /**/
                            $table, $column->getName(), $column->getName(), $type));
                    }
                }

                DB::statement(sprintf('REPAIR TABLE `?`;', $table));
                DB::statement(sprintf('OPTIMIZE TABLE `?`;', $table));
            } catch (Exception $e) {
                var_dump([ 'table' => $table, $e->getMessage() ]);
                throw $e;
            }
        }

        DB::statement('SET FOREIGN_KEY_CHECKS=1;');
    }


    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        //
    }
}