Question

When running a PHPUnit test, I would like to be able to dump output so I can debug one or two things.

I have tried the following (similar to the PHPUnit Manual example);

class theTest extends PHPUnit_Framework_TestCase
{
    /**
     * @outputBuffering disabled
     */
    public function testOutput() {
        print_r("Hello World");
        print "Ping";
        echo "Pong";
        $out = "Foo";
        var_dump($out);
    }   
}

With the following result:

PHPUnit @package_version@ by Sebastian Bergmann.

.

Time: 0 seconds, Memory: 3.00Mb

OK (1 test, 0 assertions)

Notice there is none of the expected output.

I’m using the HEAD versions of the git repos as of September 19th, 2011.

Output of php -version:

$ php -version
PHP 5.2.9 (cli) (built: Dec  8 2010 11:36:37) 
Copyright (c) 1997-2009 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2009 Zend Technologies
    with Xdebug v2.1.0, Copyright (c) 2002-2010, by Derick Rethans

Is there anything I’m doing wrong, or is this potentially a PHPUnit bug?

Answer 1

UPDATE

Just realized another way to do this that works much better than the --verbose command line option:

class TestSomething extends PHPUnit_Framework_TestCase {
    function testSomething() {
        $myDebugVar = array(1, 2, 3);
        fwrite(STDERR, print_r($myDebugVar, TRUE));
    }
}

This lets you dump anything to your console at any time without all the unwanted output that comes along with the --verbose CLI option.

---

As other answers have noted, it’s best to test output using the built-in methods like:

$this->expectOutputString('foo');

However, sometimes it’s helpful to be naughty and see one-off/temporary debugging output from within your test cases. There is no need for the var_dump hack/workaround, though. This can easily be accomplished by setting the --verbose command line option when running your test suite. For example:

$ phpunit --verbose -c phpunit.xml

This will display output from inside your test methods when running in the CLI environment.

See: Writing Tests for PHPUnit – Testing Output.