Quick reminder that you can get away with not injecting Facades. They can be swapped out with mocks quite easily.

gistfile1.php

<?php

class MyMailer {
    public function deliver()
    {
        // This facade doesn't need to be injected into the class.
        Mail::send('emails.welcome', [], function($m)
        {
            $m->to('[email protected]')
              ->subject('Welcome to the site')
              ->setCharset('UTF-8');
        });
    }
}

class ExampleTest extends TestCase {
    public function tearDown()
    {
        Mockery::close();
    }

    public function testBasicExample()
    {
        // mock it
        Mail::shouldReceive('send')->once();

        (new MyMailer)->deliver();
    }

}

This is fantastic! Can this even be done with PHPUnit's getMock? I didn't realize you could mock a static class!

This worked with the Mail class but not with a model. I am confused as to why. When I tried the same thing with a model, PHPUnit said the method shouldReceive was not defined.

It's not the Mail class, but the Mail Facade. Only facade got this magic.