Improve non strict in_array

src/Type/Php/InArrayFunctionTypeSpecifyingExtension.php

@@ -3,6 +3,7 @@
 namespace PHPStan\Type\Php;
 
 use PhpParser\Node\Expr\Array_;
+use PhpParser\Node\Expr\BinaryOp\Equal;
 use PhpParser\Node\Expr\BinaryOp\Identical;
 use PhpParser\Node\Expr\FuncCall;
 use PHPStan\Analyser\Scope;
@@ -52,7 +53,16 @@ public function specifyTypes(FunctionReflection $functionReflection, FuncCall $n
 
 		$needleExpr = $node->getArgs()[0]->value;
 		$arrayExpr = $node->getArgs()[1]->value;
-		if ($arrayExpr instanceof Array_ && $isStrictComparison) {
+
+		$needleType = $scope->getType($needleExpr);
+		$arrayType = $scope->getType($arrayExpr);
+		$arrayValueType = $arrayType->getIterableValueType();
+
+		$isStrictComparison = $isStrictComparison
+			|| $needleType->isEnum()->yes()
+			|| $arrayValueType->isEnum()->yes();
+
+		if ($arrayExpr instanceof Array_) {
 			$types = null;
 			foreach ($arrayExpr->items as $item) {
 				if ($item === null) {
@@ -62,7 +72,12 @@ public function specifyTypes(FunctionReflection $functionReflection, FuncCall $n
 					$types = null;
 					break;
 				}
-				$itemTypes = $this->typeSpecifier->resolveIdentical(new Identical($needleExpr, $item->value), $scope, $context, null);
+
+				if ($isStrictComparison) {
+					$itemTypes = $this->typeSpecifier->resolveIdentical(new Identical($needleExpr, $item->value), $scope, $context, null);
+				} else {
+					$itemTypes = $this->typeSpecifier->resolveEqual(new Equal($needleExpr, $item->value), $scope, $context, null);
+				}
 
 				if ($types === null) {
 					$types = $itemTypes;
@@ -77,14 +92,6 @@ public function specifyTypes(FunctionReflection $functionReflection, FuncCall $n
 			}
 		}
 
-		$needleType = $scope->getType($needleExpr);
-		$arrayType = $scope->getType($arrayExpr);
-		$arrayValueType = $arrayType->getIterableValueType();
-
-		$isStrictComparison = $isStrictComparison
-			|| $needleType->isEnum()->yes()
-			|| $arrayValueType->isEnum()->yes();
-
 		if (!$isStrictComparison) {
 			if (
 				$context->true()

tests/PHPStan/Analyser/nsrt/in_array_loose.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace InArrayLoose;
+
+use function PHPStan\Testing\assertType;
+
+class Foo
+{
+	public function looseComparison(
+		string $string,
+		int $int,
+		float $float,
+		bool $bool,
+		string|int $stringOrInt,
+		string|null $stringOrNull,
+	): void {
+		if (in_array($string, ['1', 'a'])) {
+			assertType("'1'|'a'", $string);
+		}
+		if (in_array($string, [1, 'a'])) {
+			assertType("string", $string); // could be '1'|'a'
+		}
+		if (in_array($int, [1, 2])) {
+			assertType('1|2', $int);
+		}
+		if (in_array($int, ['1', 2])) {
+			assertType('int', $int); // could be 1|2
+		}
+		if (in_array($bool, [true])) {
+			assertType('true', $bool);
+		}
+		if (in_array($bool, [true, null])) {
+			assertType('bool', $bool);
+		}
+		if (in_array($float, [1.0, 2.0])) {
+			assertType('1.0|2.0', $float);
+		}
+		if (in_array($float, ['1', 2.0])) {
+			assertType('float', $float); // could be 1.0|2.0
+		}
+		if (in_array($stringOrInt, ['1', '2'])) {
+			assertType('int|string', $stringOrInt); // could be '1'|'2'|1|2
+		}
+		if (in_array($stringOrNull, ['1', 'a'])) {
+			assertType('string|null', $stringOrNull); // could be '1'|'a'
+		}
+	}
+}

tests/PHPStan/Rules/Comparison/MatchExpressionRuleTest.php

@@ -590,4 +590,13 @@ public function testBug11313(): void
 		$this->analyse([__DIR__ . '/data/bug-11313.php'], []);
 	}
 
+	public function testBug9436(): void
+	{
+		if (PHP_VERSION_ID < 80000) {
+			$this->markTestSkipped('Test requires PHP 8.0.');
+		}
+
+		$this->analyse([__DIR__ . '/data/bug-9436.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Comparison/data/bug-9436.php

@@ -0,0 +1,15 @@
+<?php // lint >= 8.0
+
+namespace Bug9436;
+
+$foo = rand(0, 100);
+
+if (!in_array($foo, [0, 1, 2])) {
+	exit();
+}
+
+$bar = match ($foo) {
+	0 => 'a',
+	1 => 'b',
+	2 => 'c',
+};