Assertions done on a variable used in a closure should be transferred…

… inside the closure

src/Analyser/MutatingScope.php

@@ -2661,20 +2661,35 @@ public function enterAnonymousFunction(
 		}
 
 		$nativeTypes = [];
+		$moreSpecificTypes = [];
 		foreach ($closure->uses as $use) {
 			if (!is_string($use->var->name)) {
 				throw new \PHPStan\ShouldNotHappenException();
 			}
 			if ($use->byRef) {
 				continue;
 			}
-			if ($this->hasVariableType($use->var->name)->no()) {
+			$variableName = $use->var->name;
+			if ($this->hasVariableType($variableName)->no()) {
 				$variableType = new ErrorType();
 			} else {
-				$variableType = $this->getVariableType($use->var->name);
-				$nativeTypes[sprintf('$%s', $use->var->name)] = $this->getNativeType($use->var);
+				$variableType = $this->getVariableType($variableName);
+				$nativeTypes[sprintf('$%s', $variableName)] = $this->getNativeType($use->var);
+			}
+			$variableTypes[$variableName] = VariableTypeHolder::createYes($variableType);
+			foreach ($this->moreSpecificTypes as $exprString => $moreSpecificType) {
+				$matches = \Nette\Utils\Strings::matchAll($exprString, '#^\$([a-zA-Z_\x7f-\xff][a-zA-Z_0-9\x7f-\xff]*)#');
+				if ($matches === []) {
+					continue;
+				}
+
+				$matches = array_column($matches, 1);
+				if (!in_array($variableName, $matches, true)) {
+					continue;
+				}
+
+				$moreSpecificTypes[$exprString] = $moreSpecificType;
 			}
-			$variableTypes[$use->var->name] = VariableTypeHolder::createYes($variableType);
 		}
 
 		if ($this->hasVariableType('this')->yes() && !$closure->static) {
@@ -2693,7 +2708,7 @@ public function enterAnonymousFunction(
 			$this->getFunction(),
 			$this->getNamespace(),
 			$variableTypes,
-			[],
+			$moreSpecificTypes,
 			$this->inClosureBindScopeClass,
 			$anonymousFunctionReflection,
 			true,
@@ -2740,7 +2755,7 @@ public function enterArrowFunction(Expr\ArrowFunction $arrowFunction): self
 			$this->getFunction(),
 			$this->getNamespace(),
 			$variableTypes,
-			[],
+			$this->moreSpecificTypes,
 			$this->inClosureBindScopeClass,
 			$anonymousFunctionReflection,
 			true,
@@ -3502,7 +3517,7 @@ public function processClosureScope(
 			$this->getFunction(),
 			$this->getNamespace(),
 			$variableTypes,
-			[],
+			$this->moreSpecificTypes,
 			$this->inClosureBindScopeClass,
 			$this->anonymousFunctionReflection,
 			$this->inFirstLevelStatement,

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -10302,6 +10302,11 @@ public function dataNullSafe(): array
 		return $this->gatherAssertTypes(__DIR__ . '/data/nullsafe.php');
 	}
 
+	public function dataRememberSpecifiedTypesAfterClosureUse(): array
+	{
+		return $this->gatherAssertTypes(__DIR__ . '/data/specified-types-closure-use.php');
+	}
+
 	/**
 	 * @param string $file
 	 * @return array<string, mixed[]>
@@ -10475,6 +10480,7 @@ private function gatherAssertTypes(string $file): array
 	 * @dataProvider dataBug2378
 	 * @dataProvider dataMatchExpression
 	 * @dataProvider dataNullSafe
+	 * @dataProvider dataRememberSpecifiedTypesAfterClosureUse
 	 * @param string $assertType
 	 * @param string $file
 	 * @param mixed ...$args

tests/PHPStan/Analyser/data/specified-types-closure-use.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace SpecifiedTypesClosureUse;
+
+use PhpParser\Node\Expr\MethodCall;
+use PhpParser\Node\Identifier;
+use function PHPStan\Analyser\assertType;
+
+class Foo
+{
+
+	public function doFoo(MethodCall $call, MethodCall $bar): void
+	{
+		if ($call->name instanceof Identifier && $bar->name instanceof Identifier) {
+			function () use ($call): void {
+				assertType('PhpParser\Node\Identifier', $call->name);
+				assertType('mixed', $bar->name);
+			};
+
+			assertType('PhpParser\Node\Identifier', $call->name);
+		}
+	}
+
+	public function doBar(MethodCall $call, MethodCall $bar): void
+	{
+		if ($call->name instanceof Identifier && $bar->name instanceof Identifier) {
+			$a = 1;
+			function () use ($call, &$a): void {
+				assertType('PhpParser\Node\Identifier', $call->name);
+				assertType('mixed', $bar->name);
+			};
+
+			assertType('PhpParser\Node\Identifier', $call->name);
+		}
+	}
+
+}