Fixed inferring return type coming from array_map

Author: ondrejmirtes

src/Analyser/MutatingScope.php

@@ -37,6 +37,7 @@
 use PHPStan\Reflection\ParametersAcceptor;
 use PHPStan\Reflection\ParametersAcceptorSelector;
 use PHPStan\Reflection\PassedByReference;
+use PHPStan\Reflection\Php\DummyParameter;
 use PHPStan\Reflection\Php\PhpFunctionFromParserNodeReflection;
 use PHPStan\Reflection\Php\PhpMethodFromParserNodeReflection;
 use PHPStan\Reflection\PropertyReflection;
@@ -1281,7 +1282,25 @@ private function resolveType(Expr $node): Type
 $returnType = TypehintHelper::decideType($this->getFunctionType($node->returnType, false, false), $returnType);
 }
 } else {
-$closureScope = $this->enterAnonymousFunctionWithoutReflection($node);
+$callableParameters = null;
+$arg = $node->getAttribute('parent');
+if ($arg instanceof Arg) {
+$funcCall = $arg->getAttribute('parent');
+$argOrder = $arg->getAttribute('expressionOrder');
+if ($funcCall instanceof FuncCall && $funcCall->name instanceof Name) {
+$functionName = $this->reflectionProvider->resolveFunctionName($funcCall->name, $this);
+if (
+$functionName === 'array_map'
+&& $argOrder === 0
+&& isset($funcCall->args[1])
+) {
+$callableParameters = [
+new DummyParameter('item', $this->getType($funcCall->args[1]->value)->getIterableValueType(), false, PassedByReference::createNo(), false, null),
+];
+}
+}
+}
+$closureScope = $this->enterAnonymousFunctionWithoutReflection($node, $callableParameters);
 $closureReturnStatements = [];
 $closureYieldStatements = [];
 $closureExecutionEnds = [];

src/NodeVisitor/StatementOrderVisitor.php

@@ -40,7 +40,10 @@ public function enterNode(Node $node)
 $node->setAttribute('statementOrder', $order);
 $node->setAttribute('statementDepth', $this->depth);
 
-if ($node instanceof Node\Expr && count($this->expressionOrderStack) > 0) {
+if (
+($node instanceof Node\Expr || $node instanceof Node\Arg)
+&& count($this->expressionOrderStack) > 0
+) {
 $expressionOrder = $this->expressionOrderStack[count($this->expressionOrderStack) - 1];
 $node->setAttribute('expressionOrder', $expressionOrder);
 $node->setAttribute('expressionDepth', $this->expressionDepth);

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -10923,6 +10923,11 @@ public function dataBug4498(): array
 return $this->gatherAssertTypes(__DIR__ . '/data/bug-4498.php');
 }
 
+public function dataBug4587(): array
+{
+return $this->gatherAssertTypes(__DIR__ . '/data/bug-4587.php');
+}
+
 /**
  * @param string $file
  * @return array<string, mixed[]>
@@ -11169,6 +11174,7 @@ private function gatherAssertTypes(string $file): array
  * @dataProvider dataBug3769
  * @dataProvider dataBugInstanceOfClassString
  * @dataProvider dataBug4498
+ * @dataProvider dataBug4587
  * @param string $assertType
  * @param string $file
  * @param mixed ...$args

tests/PHPStan/Analyser/data/bug-4587.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace Bug4587;
+
+use function PHPStan\Analyser\assertType;
+
+class HelloWorld
+{
+public function a(): void
+{
+/** @var list<array{a: int}> $results */
+$results = [];
+
+$type = array_map(static function (array $result): array {
+assertType('array(\'a\' => int)', $result);
+return $result;
+}, $results);
+
+assertType('array<int, array(\'a\' => int)>', $type);
+}
+
+public function b(): void
+{
+/** @var list<array{a: int}> $results */
+$results = [];
+
+$type = array_map(static function (array $result): array {
+assertType('array(\'a\' => int)', $result);
+$result['a'] = (string) $result['a'];
+assertType('array(\'a\' => string&numeric)', $result);
+
+return $result;
+}, $results);
+
+assertType('array<int, array(\'a\' => string&numeric)>', $type);
+}
+}

tests/PHPStan/Analyser/data/generics.php

@@ -218,7 +218,7 @@ function testArrayMap(array $listOfIntegers)
 
 return (string) $int;
 }, $listOfIntegers);
-assertType('array<string>', $strings);
+assertType('array<string&numeric>', $strings);
 }
 
 /**