Using SQLite for unit testing a mysql migrations setup

I want to use SQLite for PHPunit tests. We are using the mysql driver, so we have created our migrations based on that... meaning we are using nullables for default values. MYSQL doesn't care about this. SQLite, apparently, does.

Migrations:

Schema::table('users', function ($table) {
    $table->string('username', 132)->nullable();

TestCase snippet: configuring phpunit environment

    $app['config']->set('database.connections.testbench', [
            'driver'   => 'sqlite',
            'database' => ':memory:',
            'prefix'   => ''
        ]

Running phpunit outputs:

Cannot add a NOT NULL column with default value NULL

I noticed there was a "STRICT" mode for mysql in the database.php configuration file that you can set to false which handles invalid or missing data types:

    'mysql' => [
        'driver'    => 'mysql',
         ...
        'strict'    => false,
    ],

So I started looking for a strict mode for SQLite and found Strict Mode here, tried setting PRAGMA strict=ON; to off

    $app['config']->set('database.connections.testbench', [
            'driver'   => 'sqlite',
            'database' => ':memory:',
            'prefix'   => '',
            'strict'   => false
        ]

But this did not fix it.

Is there a way to set SQLite to ignore nullable() values set in migrations (aimed at mysql configurations) so I can run my unit tests quickly with SQLite in memory?

My alternatives are:

• remove all nullable() options for migrations and add defaults, which will take forever
• use mysql instead of sqlite, which will be much slower