bug in PHPUnit Manual 9.5: Examples 2.7 and 2.8

[ricfio]

Problem

Q	A
PHPUnit version	9.5.4
PHP version	8.0.1
Installation Method	Composer

TypeError: DataTest::testAdd(): Argument #1 ($a) must be of type int, string given, called in /workspaces/phpunit-tutorial/www/vendor/phpunit/phpunit/src/Framework/TestCase.php on line 1526

Fix

master...ricfio:patch-1

How to reproduce

Example 2.7 Using a data provider that returns an Iterator object

<?php declare(strict_types=1);
use PHPUnit\Framework\TestCase;

final class DataTest extends TestCase
{
    /**
     * @dataProvider additionProvider
     */
    public function testAdd(int $a, int $b, int $expected): void
    {
        $this->assertSame($expected, $a + $b);
    }

    public function additionProvider(): CsvFileIterator
    {
        return new CsvFileIterator('data.csv');
    }
}

Example 2.8 The CsvFileIterator class

<?php declare(strict_types=1);
use PHPUnit\Framework\TestCase;

final class CsvFileIterator implements Iterator
{
    private $file;
    private $key = 0;
    private $current;

    public function __construct(string $file)
    {
        $this->file = fopen($file, 'r');
    }

    public function __destruct()
    {
        fclose($this->file);
    }

    public function rewind(): void
    {
        rewind($this->file);

        $this->current = fgetcsv($this->file);
        $this->key     = 0;
    }

    public function valid(): bool
    {
        return !feof($this->file);
    }

    public function key(): int
    {
        return $this->key;
    }

    public function current(): array
    {
        return $this->current;
    }

    public function next(): void
    {
        $this->current = fgetcsv($this->file);

        $this->key++;
    }
}

data.csv

0,0,0
0,1,1
1,0,1
1,1,3

# phpunit tests/DataTest.php
PHPUnit 9.5.4 by Sebastian Bergmann and contributors.

EEEE                                                                4 / 4 (100%)

Time: 00:00.215, Memory: 4.00 MB

There were 4 errors:

1) DataTest::testAdd with data set #0 ('0', '0', '0')
TypeError: DataTest::testAdd(): Argument #1 ($a) must be of type int, string given, called in /workspaces/phpunit-tutorial/www/vendor/phpunit/phpunit/src/Framework/TestCase.php on line 1526

/workspaces/phpunit-tutorial/www/tests/DataTest.php:10

2) DataTest::testAdd with data set #1 ('0', '1', '1')
TypeError: DataTest::testAdd(): Argument #1 ($a) must be of type int, string given, called in /workspaces/phpunit-tutorial/www/vendor/phpunit/phpunit/src/Framework/TestCase.php on line 1526

/workspaces/phpunit-tutorial/www/tests/DataTest.php:10

3) DataTest::testAdd with data set #2 ('1', '0', '1')
TypeError: DataTest::testAdd(): Argument #1 ($a) must be of type int, string given, called in /workspaces/phpunit-tutorial/www/vendor/phpunit/phpunit/src/Framework/TestCase.php on line 1526

/workspaces/phpunit-tutorial/www/tests/DataTest.php:10

4) DataTest::testAdd with data set #3 ('1', '1', '3')
TypeError: DataTest::testAdd(): Argument #1 ($a) must be of type int, string given, called in /workspaces/phpunit-tutorial/www/vendor/phpunit/phpunit/src/Framework/TestCase.php on line 1526

/workspaces/phpunit-tutorial/www/tests/DataTest.php:10

ERRORS!
Tests: 4, Assertions: 0, Errors: 4.

How to solve

In src/CsvFileIterator change this

        $this->current = fgetcsv($this->file);

with this

        $this->current = fgetcsv($this->file);
        if (is_array($row)) {
            $row = array_map('intval', $row);
        }