From dc25cfceb6634ea42e87e1140570c136213d44ac Mon Sep 17 00:00:00 2001
From: Markus Staab <maggus.staab@googlemail.com>
Date: Sun, 20 Nov 2022 13:55:09 +0100
Subject: [PATCH] Fix `pathinfo($s, PATHINFO_ALL)` return type

---
 ...infoFunctionDynamicReturnTypeExtension.php | 40 +++++++++++++------
 .../Analyser/NodeScopeResolverTest.php        |  1 +
 tests/PHPStan/Analyser/data/pathinfo.php      | 17 ++++++++
 3 files changed, 45 insertions(+), 13 deletions(-)
 create mode 100644 tests/PHPStan/Analyser/data/pathinfo.php

diff --git a/src/Type/Php/PathinfoFunctionDynamicReturnTypeExtension.php b/src/Type/Php/PathinfoFunctionDynamicReturnTypeExtension.php
index 1376ed4ff8e..df935750225 100644
--- a/src/Type/Php/PathinfoFunctionDynamicReturnTypeExtension.php
+++ b/src/Type/Php/PathinfoFunctionDynamicReturnTypeExtension.php
@@ -5,13 +5,15 @@
 use PhpParser\Node;
 use PHPStan\Analyser\Scope;
 use PHPStan\Reflection\FunctionReflection;
-use PHPStan\Reflection\ParametersAcceptorSelector;
 use PHPStan\Type\Constant\ConstantArrayTypeBuilder;
+use PHPStan\Type\Constant\ConstantIntegerType;
 use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\DynamicFunctionReturnTypeExtension;
 use PHPStan\Type\StringType;
 use PHPStan\Type\Type;
+use PHPStan\Type\TypeCombinator;
 use function count;
+use const PATHINFO_ALL;
 
 class PathinfoFunctionDynamicReturnTypeExtension implements DynamicFunctionReturnTypeExtension
 {
@@ -25,24 +27,36 @@ public function getTypeFromFunctionCall(
 		FunctionReflection $functionReflection,
 		Node\Expr\FuncCall $functionCall,
 		Scope $scope,
-	): Type
+	): ?Type
 	{
 		$argsCount = count($functionCall->getArgs());
 		if ($argsCount === 0) {
-			return ParametersAcceptorSelector::selectSingle($functionReflection->getVariants())->getReturnType();
-		} elseif ($argsCount === 1) {
-			$pathType = $scope->getType($functionCall->getArgs()[0]->value);
-
-			$builder = ConstantArrayTypeBuilder::createEmpty();
-			$builder->setOffsetValueType(new ConstantStringType('dirname'), new StringType(), !$pathType->isNonEmptyString()->yes());
-			$builder->setOffsetValueType(new ConstantStringType('basename'), new StringType());
-			$builder->setOffsetValueType(new ConstantStringType('extension'), new StringType(), true);
-			$builder->setOffsetValueType(new ConstantStringType('filename'), new StringType());
+			return null;
+		}
 
-			return $builder->getArray();
+		$pathType = $scope->getType($functionCall->getArgs()[0]->value);
+
+		$builder = ConstantArrayTypeBuilder::createEmpty();
+		$builder->setOffsetValueType(new ConstantStringType('dirname'), new StringType(), !$pathType->isNonEmptyString()->yes());
+		$builder->setOffsetValueType(new ConstantStringType('basename'), new StringType());
+		$builder->setOffsetValueType(new ConstantStringType('extension'), new StringType(), true);
+		$builder->setOffsetValueType(new ConstantStringType('filename'), new StringType());
+		$arrayType = $builder->getArray();
+
+		if ($argsCount === 1) {
+			return $arrayType;
+		} elseif ($argsCount >= 2) {
+			$flagsType = $scope->getType($functionCall->getArgs()[1]->value);
+			if ($flagsType instanceof ConstantIntegerType) {
+				if ($flagsType->getValue() === PATHINFO_ALL) {
+					return $arrayType;
+				}
+
+				return new StringType();
+			}
 		}
 
-		return new StringType();
+		return TypeCombinator::union($arrayType, new StringType());
 	}
 
 }
diff --git a/tests/PHPStan/Analyser/NodeScopeResolverTest.php b/tests/PHPStan/Analyser/NodeScopeResolverTest.php
index ac8b6a84bc2..379da6c4a16 100644
--- a/tests/PHPStan/Analyser/NodeScopeResolverTest.php
+++ b/tests/PHPStan/Analyser/NodeScopeResolverTest.php
@@ -1132,6 +1132,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8361.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8373.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/../Rules/Functions/data/bug-8389.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/pathinfo.php');
 	}
 
 	/**
diff --git a/tests/PHPStan/Analyser/data/pathinfo.php b/tests/PHPStan/Analyser/data/pathinfo.php
new file mode 100644
index 00000000000..716e14fbf66
--- /dev/null
+++ b/tests/PHPStan/Analyser/data/pathinfo.php
@@ -0,0 +1,17 @@
+<?php
+
+namespace pathinfo;
+
+use function PHPStan\Testing\assertType;
+
+function doFoo(string $s,  int $i) {
+	assertType('array{dirname?: string, basename: string, extension?: string, filename: string}|string', pathinfo($s,  $i));
+
+	assertType('array{dirname?: string, basename: string, extension?: string, filename: string}', pathinfo($s));
+	assertType('array{dirname?: string, basename: string, extension?: string, filename: string}', pathinfo($s, PATHINFO_ALL));
+
+	assertType('string', pathinfo($s, PATHINFO_DIRNAME));
+	assertType('string', pathinfo($s, PATHINFO_BASENAME));
+	assertType('string', pathinfo($s, PATHINFO_EXTENSION));
+	assertType('string', pathinfo($s, PATHINFO_FILENAME));
+}