Laravel Tests not respecting phpunit.xml variables

I have a standard app built on Laravel and have been creating unit tests as I go. Everything has been based on the default MySQL DB. I have introduced MongoDB as a secondary DB needed for other data.

Here's my PHP section in the phpunit.xml

<php>
      <env name="APP_ENV" value="testing"/>
      <env name="CACHE_DRIVER" value="array"/>
      <env name="SESSION_DRIVER" value="array"/>
      <env name="QUEUE_DRIVER" value="sync"/>
      <env name="DB_CONNECTION" value="sqlite"/>
      <env name="DB_DATABASE" value=":memory:"/>
      <env name="MONGO_DATABASE" value="tap_testing"/>
</php>

My default DB for mongo is tap and I wanted to use a secondary DB tap_testing for unit tests. When I run the tests, they are writing to tap. So something is broken or I have missed a step in adding a new DB but all the online tutorials I have found said it's as simple as what I have listed above.

I have also ran into an issue last week that was tracked down to APP_ENV showing as local and not testing, so I feel like there's an underlying issue on why it's not respecting the phpunit.xml env vars.

In fact, I just ran it right now, and it's wiping my local DB instead of using an in memory DB.

I just run stuff like this in the project root:

$ phpunit
$ php laravel dusk

And this is my mongodb entry in config/database.php

'mongodb' => [
            'driver'   => env('MONGO_DRIVER','mongodb'),
            'host'     => env('MONGO_HOST', '127.0.0.1'),
            'port'     => env('MONGO_PORT', 27017),
            'database' => env('MONGO_DATABASE'),
            /*'username' => env('DB_USERNAME'),
            'password' => env('DB_PASSWORD'),*/
            'options'  => [
                'database' => 'admin' // sets the authentication database required by mongo 3
            ]
        ],

via Chebli Mohamed