Same question!

I wrote ArrayDriver for testing

@Londeren could you share this array driver please ? Thx !

I came up with the following code:

    public function testSomethingWithStorage()
    {
        $storage = $this->mockStorage();

        $storage->shouldReceive('get')->once()->andReturn('test');
        $storage->shouldReceive('put')->once()->andThrow(new Exception());

        /* another code here */
    }

    protected function mockStorage()
    {
        Storage::extend('mock', function() {
            return \Mockery::mock(\Illuminate\Contracts\Filesystem\Filesystem::class);
        });

        Config::set('filesystems.disks.mock', ['driver' => 'mock']);
        Config::set('filesystems.default', 'mock');

        return Storage::disk();
    }

It's easier than that. You handle it as a chained object:

    Storage::shouldReceive('disk->get')->once()->andReturn($contentString);

That was tested and works for me. But if you want to test the argument being sent to the 'disk' method as well, I think you can do something like this:

    Storage::shouldReceive('disk')->with($diskName)->shouldReceive('get')->once()->andReturn($contentString);