Fix match expression and treatPhpDocTypesAsCertain

Author: VincentLanglet

conf/config.level4.neon

@@ -131,6 +131,7 @@ services:
 			checkAlwaysTrueStrictComparison: %checkAlwaysTrueStrictComparison%
 			disableUnreachable: %featureToggles.disableUnreachableBranchesRules%
 			reportAlwaysTrueInLastCondition: %reportAlwaysTrueInLastCondition%
+			treatPhpDocTypesAsCertain: %treatPhpDocTypesAsCertain%
 		tags:
 			- phpstan.rules.rule
 

src/Rules/Comparison/MatchExpressionRule.php

@@ -30,6 +30,7 @@ public function __construct(
 		private bool $checkAlwaysTrueStrictComparison,
 		private bool $disableUnreachable,
 		private bool $reportAlwaysTrueInLastCondition,
+		private bool $treatPhpDocTypesAsCertain,
 	)
 	{
 	}
@@ -64,7 +65,7 @@ public function processNode(Node $node, Scope $scope): array
 					$matchCondition,
 					$armCondition->getCondition(),
 				);
-				$armConditionResult = $armConditionScope->getType($armConditionExpr);
+				$armConditionResult = ($this->treatPhpDocTypesAsCertain ? $armConditionScope->getType($armConditionExpr) : $armConditionScope->getNativeType($armConditionExpr));
 				if (!$armConditionResult instanceof ConstantBooleanType) {
 					continue;
 				}

tests/PHPStan/Rules/Comparison/MatchExpressionRuleTest.php

@@ -35,6 +35,7 @@ protected function getRule(): Rule
 			true,
 			$this->disableUnreachable,
 			$this->reportAlwaysTrueInLastCondition,
+			$this->treatPhpDocTypesAsCertain,
 		);
 	}
 
@@ -441,4 +442,14 @@ public function testReportAlwaysTrueInLastCondition(bool $reportAlwaysTrueInLast
 		$this->analyse([__DIR__ . '/data/match-always-true-last-arm.php'], $expectedErrors);
 	}
 
+	public function testBug8932(): void
+	{
+		if (PHP_VERSION_ID < 80000) {
+			$this->markTestSkipped('Test requires PHP 8.0.');
+		}
+
+		$this->treatPhpDocTypesAsCertain = false;
+		$this->analyse([__DIR__ . '/data/bug-8932.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Comparison/data/bug-8932.php

@@ -0,0 +1,18 @@
+<?php // lint >= 8.0
+
+namespace Bug8932;
+
+class HelloWorld
+{
+	/**
+	 * @param 'A'|'B' $string
+	 */
+	public function sayHello(string $string): int
+	{
+		return match ($string) {
+			'A' => 1,
+			'B' => 2,
+			default => throw new \LogicException(),
+		};
+	}
+}