You've not told us very much about what you've done, so it's difficult to respond with specifics. However, this may help you in the right direction:

$uploadedFile = new Symfony\Component\HttpFoundation\File\UploadedFile('/path/to/file', 'original-file-name.ext');
$response = $this->call('POST', 'upload', [], [$uploadedFile]);

You can mock UploadedFile so tests won't touch your disk at all. That's a trivial thing to do in many cases however not in this case )))

Mock and make a request is simple

    // specify all methods you call in your code in the array below or use shouldReceive and etc methods
    $uploadedFile1 = Mockery::mock(
        '\Symfony\Component\HttpFoundation\File\UploadedFile',
        [
            'getClientOriginalName'      => 'image-1.jpg',
            'getClientOriginalExtension' => 'jpg',
        ]
    );
    // make a request
    $response = $this->action(
        'POST', 'YourController@store', [], [ ... your parameters ...], ['images' => [$uploadedFile1]]
    );

Now the tricky part. You need to change how function 'filterFiles' in \Symfony\Component\HttpKernel\Client works. The easy way without changing framework code is changing tests/TestCase.php file the following way

<?php

/**
 * {@inheritdoc}
 */
class MockedClient extends \Illuminate\Foundation\Testing\Client
{
    /**
     * {@inheritdoc}
     *
     * Skips any filtering and returns original files.
     */
    protected function filterFiles(array $files)
    {
        return $files;
    }
}

class TestCase extends \Illuminate\Foundation\Testing\TestCase
{
	/**
	 * Creates the application.
	 *
	 * @return \Symfony\Component\HttpKernel\HttpKernelInterface
	 */
	public function createApplication()
	{
		$unitTesting = true;

		$testEnvironment = 'testing';

		return require __DIR__.'/../../bootstrap/start.php';
	}

    /**
     * {@inheritdoc}
     */
    protected function createClient(array $server = array())
    {
        return new MockedClient($this->app, $server);
    }
}

@EvgenyKovalev thanks, That is helper for me

Back to what @petercoles said, his solution needs to be completed with naming the name in the form for the file:

$uploadedFile = new Symfony\Component\HttpFoundation\File\UploadedFile('/path/to/file', 'original-file-name.ext');
$response = $this->call('POST', 'upload', [], ['file' => $uploadedFile]);

@nirradian I used your approach but now facing this error "FileNotFoundException in FileHandlerFactory.php" however file is there if I inspect $uploadedFile I see file path there, did I miss something?

@vaske here's what I did in my Laravel 5.1 unit test:

$file = new Symfony\Component\HttpFoundation\File\UploadedFile( storage_path( 'temp/test-file.csv' ), 'test-file.csv', 'text/plain', 446 );
$this->call( 'POST', '/upload', [], [], [ 'csv_file' => $file ] );
$this->assertResponseOk();

Just make sure you have the actual file in the specified location.

FYI, since I've been tearing my hair for 3 hours... you also have to specify the 6th constructing parameter as TRUE, so the UploadedFile class knows that you're uploading the image via unit testing environment.

$file = new Symfony\Component\HttpFoundation\File\UploadedFile( storage_path( 'temp/test-file.csv' ), 'test-file.csv', 'text/plain', 446, null, TRUE );

according to the class:

/* /vendor/symfony/http-foundation/Symfony/Component/HttpFoundation/Symphony/Component/HttpFoundation/File/UploadedFile.php */
...
public function __construct($path, $originalName, $mimeType = null, $size = null, $error = null, $test = false)
...

then the image upload via PHPUnit should work fine

I prefer the idea of mocking the upload as @EvgenyKovalev suggests. Any ideas how to do this in Laravel 5.1? I can't get it to work.

@suebphatt

Thanks for adding that in, I was starting to get pretty annoyed