Laravel 5 : Use different database for testing and local

Create a testing database configuration in Laravel

Edit the config\database.php file and add a testing - array into the connections array:

'connections' => [
    'testing' => [
        'driver' => env('DB_TEST_DRIVER'),
        // more details on your testing database
    ]
]

Then add the necessary variables to your .env-file.

Edit PHPUnit configuration

Open your phpunit.xml-file and add the following within your <php>-tag:

<env name="DB_CONNECTION" value="testing"/>

Now PHPUnit will run with the tests on the database you defined in the testing - array.

For Laravel 5.5, the proper way to do this is create a testing environment file called .env.testing. Here, you can define your testing environment, including the database you want to use for testing...

DB_CONNECTION=mysql
DB_HOST=127.0.0.1
DB_PORT=3306
DB_DATABASE=test DB
DB_USERNAME=test DB user
DB_PASSWORD=test DB password

Then run this command...

php artisan config:cache --env=testing

This will configure the cache to the .env.testing file parameters.

Here is a link to the documentation.