Add BleedingEdgeToggle::withBleedingEdge tests including generator guard

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: phpstan-bot

tests/PHPStan/DependencyInjection/BleedingEdgeToggleTest.php

@@ -0,0 +1,66 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\DependencyInjection;
+
+use Generator;
+use PHPStan\ShouldNotHappenException;
+use PHPStan\Testing\PHPStanTestCase;
+
+class BleedingEdgeToggleTest extends PHPStanTestCase
+{
+
+	public function testWithBleedingEdgeRunsCallbackWithToggleSet(): void
+	{
+		$backup = BleedingEdgeToggle::isBleedingEdge();
+		try {
+			BleedingEdgeToggle::setBleedingEdge(false);
+
+			$observed = BleedingEdgeToggle::withBleedingEdge(true, static fn (): bool => BleedingEdgeToggle::isBleedingEdge());
+
+			$this->assertTrue($observed);
+		} finally {
+			BleedingEdgeToggle::setBleedingEdge($backup);
+		}
+	}
+
+	public function testWithBleedingEdgeRestoresPreviousValue(): void
+	{
+		$backup = BleedingEdgeToggle::isBleedingEdge();
+		try {
+			BleedingEdgeToggle::setBleedingEdge(false);
+
+			BleedingEdgeToggle::withBleedingEdge(true, static fn (): bool => true);
+
+			$this->assertFalse(BleedingEdgeToggle::isBleedingEdge());
+		} finally {
+			BleedingEdgeToggle::setBleedingEdge($backup);
+		}
+	}
+
+	public function testWithBleedingEdgeRejectsGeneratorCallbackAndRestoresValue(): void
+	{
+		$backup = BleedingEdgeToggle::isBleedingEdge();
+		try {
+			BleedingEdgeToggle::setBleedingEdge(false);
+
+			$generatorCallback = static function (): Generator {
+				yield BleedingEdgeToggle::isBleedingEdge();
+			};
+
+			try {
+				BleedingEdgeToggle::withBleedingEdge(true, $generatorCallback);
+				$this->fail('Expected ShouldNotHappenException was not thrown.');
+			} catch (ShouldNotHappenException $e) {
+				// A generator callback would hold the toggle across a `yield` and leak it
+				// into unrelated tests - it must be rejected eagerly.
+				$this->assertStringContainsString('not allowed to yield', $e->getMessage());
+			}
+
+			// The toggle must be restored even when the callback is rejected.
+			$this->assertFalse(BleedingEdgeToggle::isBleedingEdge());
+		} finally {
+			BleedingEdgeToggle::setBleedingEdge($backup);
+		}
+	}
+
+}