Add test for #6589

Author: sebastianbergmann

ChangeLog-13.1.md

@@ -7,6 +7,7 @@ All notable changes of the PHPUnit 13.1 release series are documented in this fi
 ### Fixed
 
 * [#5860](https://github.com/sebastianbergmann/phpunit/issues/5860): PHP CLI `-d` settings are not forwarded to child processes for process isolation
+* [#6589](https://github.com/sebastianbergmann/phpunit/issues/6589): `dataSetAsStringWithData()` raises "float is not representable as int" warning for large floats in data sets
 
 ## [13.1.4] - 2026-04-15
 

tests/end-to-end/regression/6589.phpt

@@ -0,0 +1,20 @@
+--TEST--
+https://github.com/sebastianbergmann/phpunit/issues/6589
+--FILE--
+<?php declare(strict_types=1);
+$_SERVER['argv'][] = '--do-not-cache-result';
+$_SERVER['argv'][] = '--no-configuration';
+$_SERVER['argv'][] = __DIR__ . '/6589/Issue6589Test.php';
+$_SERVER['argv'][] = '--no-progress';
+
+require_once __DIR__ . '/../../bootstrap.php';
+
+(new PHPUnit\TextUI\Application)->run($_SERVER['argv']);
+--EXPECTF--
+PHPUnit %s by Sebastian Bergmann and contributors.
+
+Runtime: %s
+
+Time: %s, Memory: %s
+
+OK (1 test, 1 assertion)

tests/end-to-end/regression/6589/Issue6589Test.php

@@ -0,0 +1,27 @@
+<?php declare(strict_types=1);
+/*
+ * This file is part of PHPUnit.
+ *
+ * (c) Sebastian Bergmann <sebastian@phpunit.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+namespace PHPUnit\TestFixture\Issue6589;
+
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\TestCase;
+
+final class Issue6589Test extends TestCase
+{
+    public static function provider(): iterable
+    {
+        yield [9.223372036854776e18];
+    }
+
+    #[DataProvider('provider')]
+    public function testOne(float $value): void
+    {
+        $this->assertIsFloat($value);
+    }
+}