Convert Bug8579Test to standard rule test and assertType test

Move the Bug8579 regression test from a custom Analyser test to a
standard RuleTestCase for InstantiationRule with
rememberPossiblyImpureFunctionValues: false config.

Convert the class_exists false-not-remembered test to assertType
assertions in the existing DoNotRememberPossiblyImpureFunctionValues
test data file.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: phpstan-bot

tests/PHPStan/Analyser/Bug8579Test.php

@@ -109,3 +109,23 @@ function test(): void
 		assertType('int', impure());
 	}
 }
+
+function testClassExistsFalseNotRemembered(): void
+{
+	if (!class_exists('Bug8579FalseNotRememberedA')) {
+		// class_exists returned false here, but we don't exit
+	}
+
+	assertType('bool', class_exists('Bug8579FalseNotRememberedA'));
+}
+
+function testClassExistsFalseNotRememberedElse(): void
+{
+	if (class_exists('Bug8579FalseNotRememberedB')) {
+		// true branch
+	} else {
+		// class_exists returned false in this branch
+	}
+
+	assertType('bool', class_exists('Bug8579FalseNotRememberedB'));
+}

tests/PHPStan/Analyser/data/bug-8579-false-not-remembered.php

@@ -0,0 +1,35 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Classes;
+
+use PHPStan\Rules\Rule;
+use PHPStan\Testing\RuleTestCase;
+use function array_merge;
+
+/**
+ * @extends RuleTestCase<InstantiationRule>
+ */
+class InstantiationDoNotRememberPossiblyImpureValuesRuleTest extends RuleTestCase
+{
+
+	protected function getRule(): Rule
+	{
+		return self::getContainer()->getByType(InstantiationRule::class);
+	}
+
+	public function testBug8579(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-8579.php'], []);
+	}
+
+	public static function getAdditionalConfigFiles(): array
+	{
+		return array_merge(
+			parent::getAdditionalConfigFiles(),
+			[
+				__DIR__ . '/doNotRememberPossiblyImpureValues.neon',
+			],
+		);
+	}
+
+}

tests/PHPStan/Analyser/data/do-not-remember-possibly-impure-function-values.php

@@ -0,0 +1,2 @@
+parameters:
+	rememberPossiblyImpureFunctionValues: false