Testing Your Database

The Test Class
Setting Up a Test Database
- Migrations and Seeds
Helper Methods

The Test Class 

In order to take advantage of the built-in database tools that CodeIgniter provides for testing, your tests must extend CIUnitTestCase and use the DatabaseTestTrait:

<?php

namespace App\Database;

use CodeIgniter\Test\CIUnitTestCase;
use CodeIgniter\Test\DatabaseTestTrait;

class MyTests extends CIUnitTestCase
{
    use DatabaseTestTrait;

    // ...
}

Because special functionality executed during the setUp() and tearDown() phases, you must ensure that you call the parent’s methods if you need to use those methods, otherwise you will lose much of the functionality described here:

<?php

namespace App\Database;

use CodeIgniter\Test\CIUnitTestCase;
use CodeIgniter\Test\DatabaseTestTrait;

class MyTests extends CIUnitTestCase
{
    use DatabaseTestTrait;

    protected function setUp(): void
    {
        parent::setUp();

        // Do something here....
    }

    protected function tearDown(): void
    {
        parent::tearDown();

        // Do something here....
    }
}

Setting Up a Test Database 

When running database tests, you need to provide a database that can be used during testing. Instead of using the PHPUnit built-in database features, the framework provides tools specific to CodeIgniter. The first step is to ensure that you have set up a tests database group in app/Config/Database.php. This specifies a database connection that is only used while running tests, to keep your other data safe.

If you have multiple developers on your team, you will likely want to keep your credentials stored in the .env file. To do so, edit the file to ensure the following lines are present and have the correct information:

database.tests.hostname = localhost
database.tests.database = ci4_test
database.tests.username = root
database.tests.password = root
database.tests.DBDriver = MySQLi
database.tests.DBPrefix =
database.tests.port = 3306

Migrations and Seeds 

When running tests, you need to ensure that your database has the correct schema set up and that it is in a known state for every test. You can use migrations and seeds to set up your database, by adding a couple of class properties to your test.

<?php

namespace App\Database;

use CodeIgniter\Test\CIUnitTestCase;
use CodeIgniter\Test\DatabaseTestTrait;

class MyTests extends CIUnitTestCase
{
    use DatabaseTestTrait;

    // For Migrations
    protected $migrate     = true;
    protected $migrateOnce = false;
    protected $refresh     = true;
    protected $namespace   = 'Tests\Support';

    // For Seeds
    protected $seedOnce = false;
    protected $seed     = 'TestSeeder';
    protected $basePath = 'path/to/database/files';

    // ...
}

Migrations

$migrate

This boolean value determines whether the database migration runs before test. By default, the database is always migrated to the latest available state as defined by $namespace. If false, migration never runs. If you want to disable migration, set false.

$migrateOnce

This boolean value determines whether the database migration runs only once. If you want to run migration once before the first test, set true. If not present or false, migration runs before each test.

$refresh

This boolean value determines whether the database is completely refreshed before test. If true, all migrations are rolled back to version 0.

$namespace

By default, CodeIgniter will look in tests/_support/Database/Migrations to locate the migrations that it should run during testing. You can change this location by specifying a new namespace in the $namespace properties. This should not include the Database\Migrations sub-namespace but just the base namespace.

Important

If you set this property to null, it runs migrations from all available namespaces like php spark migrate --all.

Seeds

$seed

If present and not empty, this specifies the name of a Seed file that is used to populate the database with test data prior to test running.

$seedOnce

This boolean value determines whether the database seeding runs only once. If you want to run database seeding once before the first test, set true. If not present or false, database seeding runs before each test.

$basePath

By default, CodeIgniter will look in tests/_support/Database/Seeds to locate the seeds that it should run during testing. You can change this directory by specifying the $basePath property. This should not include the Seeds directory, but the path to the single directory that holds the sub-directory.

Helper Methods 

The DatabaseTestTrait class provides several helper methods to aid in testing your database.

Changing Database State 

regressDatabase()

Called during $refresh described above, this method is available if you need to reset the database manually.

migrateDatabase()

Called during setUp(), this method is available if you need to run migrations manually.

seed($name)

Allows you to manually load a Seed into the database. The only parameter is the name of the seed to run. The seed must be present within the path specified in $basePath.

hasInDatabase($table, $data)

Inserts a new row into the database. This row is removed after the current test runs. $data is an associative array with the data to insert into the table.

<?php

$data = [
    'email' => '[email protected]',
    'name'  => 'Joe Cool',
];
$this->hasInDatabase('users', $data);

Getting Data from Database 

grabFromDatabase($table, $column, $criteria)

Returns the value of $column from the specified table where the row matches $criteria. If more than one row is found, it will only return the first one.

<?php

$username = $this->grabFromDatabase('users', 'username', ['email' => '[email protected]']);

Assertions 

dontSeeInDatabase($table, $criteria)

Asserts that a row with criteria matching the key/value pairs in $criteria DOES NOT exist in the database.

<?php

$criteria = [
    'email'  => '[email protected]',
    'active' => 1,
];
$this->dontSeeInDatabase('users', $criteria);

seeInDatabase($table, $criteria)

Asserts that a row with criteria matching the key/value pairs in $criteria DOES exist in the database.

<?php

$criteria = [
    'email'  => '[email protected]',
    'active' => 1,
];
$this->seeInDatabase('users', $criteria);

seeNumRecords($expected, $table, $criteria)

Asserts that a number of matching rows are found in the database that match $criteria.

<?php

$criteria = [
    'active' => 1,
];
$this->seeNumRecords(2, 'users', $criteria);