respect-validation/tests/Rules/WritableTest.php

<?php

namespace Respect\Validation\Rules;

$GLOBALS['is_writable'] = null;

function is_writable($writable)
{
    $return = \is_writable($writable); // Running the real function
    if (null !== $GLOBALS['is_writable']) {
        $return             = $GLOBALS['is_writable'];
        $GLOBALS['is_writable'] = null;
    }

    return $return;
}

class WritableTest extends \PHPUnit_Framework_TestCase
{

    /**
     * @covers Respect\Validation\Rules\Writable::validate
     */
    public function testValidWritableFileShouldReturnTrue()
    {
        $GLOBALS['is_writable'] = true;

        $rule = new Writable();
        $input = '/path/of/a/valid/writable/file.txt';
        $this->assertTrue($rule->validate($input));
    }

    /**
     * @covers Respect\Validation\Rules\Writable::validate
     */
    public function testInvalidWritableFileShouldReturnFalse()
    {
        $GLOBALS['is_writable'] = false;

        $rule = new Writable();
        $input = '/path/of/an/invalid/writable/file.txt';
        $this->assertFalse($rule->validate($input));
    }

    /**
     * @covers Respect\Validation\Rules\Writable::validate
     */
    public function testShouldValidateObjects()
    {
        $rule = new Writable();
        $object = $this->getMock('SplFileInfo', array('isWritable'), array('somefile.txt'));
        $object->expects($this->once())
                ->method('isWritable')
                ->will($this->returnValue(true));

        $this->assertTrue($rule->validate($object));
    }

}