Practice_PHPUnit test of STDIN

PHPUnit Test Sample For STDIN

This is a sample PHPUnit test to check the functionability of the below function, which receives a value from "STDIN" (Standard Input) and returns that value.

function getContentsFromStdin()
{
    $contents = file_get_contents('php://stdin');
    if($contents === false){
        throw new RuntimeException('Failed to read contents from STDIN.');
    }

    return $contents;
}

The test

To test the functionability of STDIN using PHPUnit, one way is to create a mock that overrides a php:// stream as a wrapper and replaces the value from STDIN.

final class FunctionGetContentsFromStdinTest extends PHPUnitFrameworkTestCase
{
    public function testRegularInput()
    {
        $result_expect = 'World!';

        // Register stream wrapper "MockPhpStream" to "php://" protocol
        $existed = in_array('php', stream_get_wrappers());
        if ($existed) {
            stream_wrapper_unregister("php");
        }
        stream_wrapper_register("php", '\KEINOSTestsMockPhpStream');

        // Set value to STDIN
        file_put_contents('php://stdin', $result_expect);

        // Get value from function and restore registration
        $result_actual = KEINOSSamplegetContentsFromStdin();
        stream_wrapper_restore("php");

        // Test
        $this->assertSame($result_expect, $result_actual);
    }
}

The Wrapper

The wrapper script to mock the PHP:// stream.

• ./tests/MockPhpStream.php

This helpful wrapper was made by Denis in his blog post.

How to Test

To see the tests in action clone this repo and run the test.

Test it locally

$ composer install
...
$ composer test
> ./vendor/bin/phpunit --testdox --bootstrap ./vendor/autoload.php tests
PHPUnit 7.5.20 by Sebastian Bergmann and contributors.

GetContentsFromFunction
  Regular input

Time: 76 ms, Memory: 4.00 MB

OK (1 test, 1 assertion)

Test it via Docker

$ docker build -t test:local .
...
$ docker run --rm test:local
> ./vendor/bin/phpunit --testdox --bootstrap ./vendor/autoload.php tests
PHPUnit 9.1.3 by Sebastian Bergmann and contributors.

Get Contents From Function
  Regular input

Time: 00:00.030, Memory: 4.00 MB

OK (1 test, 1 assertion)