The assertDirectoryNotIsReadable() function is a builtin function in PHPUnit and is used to assert whether the directory specified is not a directory or is not readable. This assertion will return true in the case if either given directory path doesn't exist or is not readable else return false. In case of true the asserted test case got passed else test case got failed. Syntax:

assertDirectoryNotIsReadable(integer $directory, string $message = '')

Parameters: This function accepts two parameters as shown in the above syntax. The parameters are described below:

• $directory: This parameter is a string which denotes the directory path.
• $message: This parameter takes string value. When the testcase got failed this string message got displayed as error message.

Below programs illustrate the assertDirectoryNotIsReadable() function in PHPUnit: Program 1:

<?php
use PHPUnit\Framework\TestCase;

class GeeksPhpunitTestCase extends TestCase
{
    public function testNegativeTestcaseForassertDirectoryNotIsReadable()
    {
        $directoryPath = "/home/shivam/Documents/phpunit/notreadable";

        // Assert function to test whether given
        // directory path either doesn't exists or not readable
        $this->assertDirectoryNotIsReadable(
            $directoryPath,
            "directoryPath either doesn't exists or not readable"
        );
    }
}

?>

Output:

PHPUnit 8.2.5 by Sebastian Bergmann and contributors.

F                                                                   1 / 1 (100%)

Time: 89 ms, Memory: 10.00 MB

There was 1 failure:

1) GeeksPhpunitTestCase::testNegativeTestcaseForAssertDirectoryNotIsReadable
directoryPath either doesn't exists or not readable
Failed asserting that directory "/home/shivam/Documents/geeks/pgp" exists.

/home/shivam/Documents/geeks/phpunit/abc.php:13

FAILURES!
Tests: 1, Assertions: 1, Failures: 1.

Program 2:

<?php
use PHPUnit\Framework\TestCase;

class GeeksPhpunitTestCase extends TestCase
{
    public function testPositiveTestcaseForAssertDirectoryNotIsReadable()
    {
        $directoryPath = "/home/shivam/Documents/geeks";

        // Assert function to test whether given
        // directory path exists or not readable
        $this->assertDirectoryNotIsReadable(
            $directoryPath,
            "directoryPath either doesn't exists or not readable"
        );
    }
}

?>

Output:

PHPUnit 8.2.5 by Sebastian Bergmann and contributors.

.                                                                   1 / 1 (100%)

Time: 67 ms, Memory: 10.00 MB

OK (1 test, 1 assertion)

Note: To run testcases with phpunit follow steps from here. Also, assertDirectoryNotIsReadable() is supported by phpunit 7 and above.