PHPUnit assertFileIsReadable() Function

The assertFileIsReadable() function is a builtin function in PHPUnit and is used to assert whether the assertfile specified is a file name is readable or not. This assertion will return true in the case if either given filename exists and is readable else return false. In case of true the asserted test case got passed else test case got failed.

Syntax:

assertFileIsReadable(string $filename[, string $message = ''])

Parameters: This function accepts two parameters as mentioned above and described below:

• $filename: This parameter is a string that denotes the file name.
• $message: This parameter takes a string value. When the test case got failed this string message got displayed as an error message.

Below examples illustrate the assertFileIsReadable() function in PHPUnit:

Example 1:

PHP

<?php
use PHPUnit\Framework\TestCase;

class GeeksPhpunitTestCase extends TestCase
{
    public function testNegativeTestcaseForAssertFileIsReadable()
    {
        $filename = "/home/lovely/Documents/phpunit";

        // Assert function to test whether the given
        // file name either exists and readable
        $this->assertFileIsReadable(
            $filename,
            "File name  exists and readable"
        );
    }
}

?>

Output:

PHPUnit 8.5.8 by Sebastian Bergmann and contributors.

F                                                       1 / 1 (100%)

Time: 90 ms, Memory: 10.00 MB

There was 1 failure:

1) GeeksPhpunitTestCase::testNegativeTestcaseForAssertFileIsReadable
File name  exists and readable
Failed asserting that file "/home/lovely/Documents/phpunit" exists.

/home/lovely/Documents/php/test.php:15

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

Example 2:

PHP

<?php
use PHPUnit\Framework\TestCase;

class GeeksPhpunitTestCase extends TestCase
{
    public function testPositiveTestcaseForAssertFileIsReadable()
    {
        $filename = "/home/lovely/Documents/php";

        // Assert function to test whether the given
        // file name either exists and readable
        $this->assertFileIsReadable(
            $filename,
            "File name  exists and readable"
        );
    }
}

?>

Output:

 PHPUnit 8.5.8 by Sebastian Bergmann and contributors.

.                                                 1 / 1 (100%)

Time: 87 ms, Memory: 10.00 MB

OK (1 test, 2 assertions)

Reference:https://phpunit.readthedocs.io/en/9.2/assertions.html#assertfileisreadable