PHPUnit Test error: Object of class (...) could not be converted to string

Question

First of all, I'm new in PHPUnit testing and PHP, sorry if I'm missing something too obvious.

Ok, now, for my question: I'm using a Virtual File System called VfsStream to test the function unlink( ). For some reason in my testing this error occurred:

[bianca@cr-22ncg22 tests-phpunit]$ phpunit
PHPUnit 4.6.10 by Sebastian Bergmann and contributors.

Configuration read from /var/www/html/tests-phpunit/phpunit.xml

E

Time: 27 ms, Memory: 4.50Mb

There was 1 error:

1) test\UnlinkTest\UnlinkTest::testUnlink
Object of class App\Libraries\Unlink could not be converted to string

/var/www/html/tests-phpunit/test/UnlinkTest.php:21
/home/bianca/.composer/vendor/phpunit/phpunit/src/TextUI/Command.php:153
/home/bianca/.composer/vendor/phpunit/phpunit/src/TextUI/Command.php:105

FAILURES!
Tests: 1, Assertions: 0, Errors: 1.

I know is something with my Unlink class and what it's returning, but I don't know what is.

The class I'm testing:

class Unlink {

    public function unlinkFile($file) {

        if (!unlink($file)) {
            echo ("Error deleting $file");
        }
        else {
            echo ("Deleted $file");
        }

        return unlink($file);
    }

}

?>

The class where my tests are:

use org\bovigo\vfs\vfsStream;
use App\Libraries\Unlink;

class UnlinkTest extends \PHPUnit_Framework_TestCase {

    public function setUp() {
        $root = vfsStream::setup('home');
        $removeFile = new Unlink();
    }

    public function tearDown() {
        $root = null;
    }

    public function testUnlink() {
        $root = vfsStream::setup('home');
        $removeFile = new Unlink();
        vfsStream::newFile('test.txt', 0744)->at($root)->setContent("The new contents of the file");
        $this->$removeFile->unlinkFile(vfsStream::url('home/test.txt'));
        $this->assertFalse(var_dump(file_exists(vfsStream::url('home/test.txt'))));
    }

}

?>

Anybody can help me to fix it?

I'm not sure about doing `assertFalse(var_dump(...))` - var_dump doesn't return a boolean. — duncan, Mar 31 '16 at 19:50

score 2 · Accepted Answer · answered Mar 31 '16 at 20:00

The error you're getting is because initially you create this local variable:

$removeFile = new Unlink();

But then you refer to it as $this->$removeFile when you do:

$this->$removeFile->unlinkFile(vfsStream::url('home/test.txt'));

That's not correct; you might use that where you have a class variable and you want to refer to it dynamically. e.g.

class YourClass {
    public $foo;
    public $bar;

    public function __construct() {
        $this->foo = 'hello';
        $this->bar = 'world';
    }

    public function doStuff() {
        $someVariable = 'foo';

        echo $this->$someVariable;  // outputs 'hello'
    }
}

All you need to do is get rid of the $this, and change it to:

$removeFile->unlinkFile(vfsStream::url('home/test.txt'));

I knew it was a simple error like this! haha Thank you, @duncan. Now I need to fix other problems with vfsStream lol — B. Pereira, Mar 31 '16 at 20:08
@B.Pereira if this answer solved your issue please accept it. If you're not familiar with stackoverflow please take a tour here: http://stackoverflow.com/tour — Jakub Zalas, Apr 01 '16 at 07:35

PHPUnit Test error: Object of class (...) could not be converted to string

1 Answers1