Understand array properties being overwritten in foreach too

Author: ondrejmirtes

src/Analyser/NodeScopeResolver.php

@@ -1284,7 +1284,7 @@ private function processStmtNode(
 				&& $stmt->keyVar !== null
 				&& $exprType->isArray()->yes()
 				&& $exprType->isConstantArray()->no()
-				&& !$hasExpr->no()
+				&& (!$hasExpr->no() || !$stmt->expr instanceof Variable)
 			) {
 				$arrayExprDimFetch = new ArrayDimFetch($stmt->expr, $stmt->keyVar);
 				$arrayDimFetchLoopTypes = [];
@@ -1332,6 +1332,12 @@ private function processStmtNode(
 							$newExprNativeType,
 							$hasExpr,
 						);
+					} else {
+						$finalScope = $finalScope->assignExpression(
+							$stmt->expr,
+							$newExprType,
+							$newExprNativeType,
+						);
 					}
 				}
 			}

tests/PHPStan/Analyser/nsrt/overwritten-arrays.php

@@ -3,11 +3,27 @@
 namespace OverwrittenArrays;
 
 use function PHPStan\Testing\assertType;
-use function rad2deg;
 
 class Foo
 {
 
+	/** @var array<string> */
+	private array $a;
+
+	public function doFooProp1(): void
+	{
+		foreach ($this->a as $k => $v) {
+			if (rand(0, 1)) {
+				$this->a[$k] = 2;
+				continue;
+			}
+
+			$this->a[$k] = 1;
+		}
+
+		assertType('array<1|2>', $this->a);
+	}
+
 	/**
 	 * @param array<int, string> $a
 	 */