Shredding data in in-memory SQLITE database in PHPUnit

I am currently researching how to test a database in PHPUnit framework and ran into a problem that I don't want to connect to a real database in my tests. This is because when I run tests on a different computer, that computer may not have the same database.

I have implemented the trait \PHPUnit\DbUnit\TestCaseTrait

and set the following methods:

/**
 * Returns the test database connection.
 *
 * @return \PHPUnit\DbUnit\Database\Connection
 */
protected function getConnection()
{
    $pdo = new PDO('sqlite::memory:');
    return $this->createDefaultDBConnection($pdo, ':memory:');
}

/**
 * Returns the test dataset.
 *
 * @return \PHPUnit\DbUnit\DataSet\IDataSet
 */
protected function getDataSet()
{
    return $this->createXMLDataSet(dirname(__FILE__) . '/test-dataset.xml');
}

      

        
        
        
      

    

The dataset file is present and found correctly.

In my method setUp

from my test, I have set a variable in an object to an instance \PDO

.

/**
 * @var PDO $databaseServerConnection
 */
private $databaseServerConnection;

public function setUp()
{
    $this->databaseServerConnection = $this->getConnection()->getConnection();
}

      

        
        
        
      

    

I expected to be able to now use this PDO connection with data retrieved from the dataset file in a method getDataSet()

.

For my own attempt, I tried to compare them with the following code:

# Specify the tables we want to have in our connection dataset
$tables = ['users'];

# Create the dataset in the connection with the tables
$dataset = $this->getConnection()->createDataSet($tables);

# Query all results from the user table  in the connection
$queryTable = $this->getConnection()->createQueryTable(
    'users', 'SELECT * FROM users'
);

# Get the raw table data from the dataset file
$expectedTable = $this->getDataSet()->getTable('users');

# Check if theyre equal
$this->assertTablesEqual($queryTable, $expectedTable);

      

        
        
        
      

    

While debugging, I noticed that the array variable $tables

inside is $dataset

just empty. Here a is a var_dump

variable $dataset

.

class PHPUnit\DbUnit\Database\FilteredDataSet#18 (3) {
  protected $tableNames =>
  array(1) {
    [0] =>
    string(5) "users"
  }
  protected $tables =>
  array(0) {
  }
  protected $databaseConnection =>
  class PHPUnit\DbUnit\Database\DefaultConnection#16 (2) {
    protected $connection =>
    class PDO#15 (0) {
    }
    protected $metaData =>
    class PHPUnit\DbUnit\Database\Metadata\Sqlite#17 (6) {
      protected $columns =>
      array(0) {
        ...
      }
      protected $keys =>
      array(0) {
        ...
      }
      protected $truncateCommand =>
      string(11) "DELETE FROM"
      protected $pdo =>
      class PDO#15 (0) {
        ...
      }
      protected $schema =>
      string(8) ":memory:"
      protected $schemaObjectQuoteChar =>
      string(1) """
    }
  }
}

      

        
        
        
      

    

Also the array $data

inside the variable $queryTable

is null

. Here a is the var_dump

variable he $queryTable

.

class PHPUnit\DbUnit\DataSet\QueryTable#22 (6) {
  protected $query =>
  string(19) "SELECT * FROM users"
  protected $databaseConnection =>
  class PHPUnit\DbUnit\Database\DefaultConnection#20 (2) {
    protected $connection =>
    class PDO#19 (0) {
    }
    protected $metaData =>
    class PHPUnit\DbUnit\Database\Metadata\Sqlite#21 (6) {
      protected $columns =>
      array(0) {
        ...
      }
      protected $keys =>
      array(0) {
        ...
      }
      protected $truncateCommand =>
      string(11) "DELETE FROM"
      protected $pdo =>
      class PDO#19 (0) {
        ...
      }
      protected $schema =>
      string(8) ":memory:"
      protected $schemaObjectQuoteChar =>
      string(1) """
    }
  }
  protected $tableName =>
  string(5) "users"
  protected $tableMetaData =>
  NULL
  protected $data =>
  NULL
  private $other =>
  NULL
}

      

        
        
        
      

    

Whereas the array $data

inside the variable is $expectedTable

filled with data created in the dataset file.

class PHPUnit\DbUnit\DataSet\DefaultTable#30 (3) {
  protected $tableMetaData =>
  class PHPUnit\DbUnit\DataSet\DefaultTableMetadata#34 (3) {
    protected $columns =>
    array(3) {
      [0] =>
      string(2) "id"
      [1] =>
      string(4) "name"
      [2] =>
      string(5) "email"
    }
    protected $primaryKeys =>
    array(0) {
    }
    protected $tableName =>
    string(5) "users"
  }
  protected $data =>
  array(4) {
    [0] =>
    array(3) {
      'id' =>
      string(1) "1"
      'name' =>
      string(3) "test1"
      'email' =>
      string(9) "test1@me.nl"
    }
    [1] =>
    array(3) {
      'id' =>
      string(1) "2"
      'name' =>
      string(3) "test2"
      'email' =>
      string(9) "test2@me.nl"
    }
    [2] =>
    array(3) {
      'id' =>
      string(1) "3"
      'name' =>
      string(6) "test3"
      'email' =>
      string(12) "test3@me.nl"
    }
    [3] =>
    array(3) {
      'id' =>
      string(1) "4"
      'name' =>
      string(4) "test4"
      'email' =>
      string(10) "test4@me.nl"
    }
  }
  private $other =>
  NULL
}

      

        
        
        
      

    

I also tried 2 queries on the pdo link object inside the method getConnection()

to create a table with the values ​​inside them:

protected function getConnection()
{
    $pdo = new PDO('sqlite::memory:');
    $pdo->exec("CREATE TABLE users (id PRIMARY KEY, name VARCHAR(50), email VARCHAR(50))");
    $pdo->exec("INSERT INTO users (id, name, email) VALUES (20, 'Bas', 'aa@me')");

    return $this->createDefaultDBConnection($pdo, ':memory:');
}

      

        
        
        
      

    

How is it that I have no data available on my connection, and how can I import data from a dataset file here to pass the test?

Also, is it good practice for this?