Foreach can append to the array but it does not change the number of iterations

Closes phpstan/phpstan#8924

Author: ondrejmirtes

src/Analyser/MutatingScope.php

@@ -3121,37 +3121,37 @@ public function enterMatch(Expr\Match_ $expr): self
 		return $this->assignExpression($condExpr, $type, $nativeType);
 	}
 
-	public function enterForeach(Expr $iteratee, string $valueName, ?string $keyName): self
+	public function enterForeach(self $originalScope, Expr $iteratee, string $valueName, ?string $keyName): self
 	{
-		$iterateeType = $this->getType($iteratee);
-		$nativeIterateeType = $this->getNativeType($iteratee);
+		$iterateeType = $originalScope->getType($iteratee);
+		$nativeIterateeType = $originalScope->getNativeType($iteratee);
 		$scope = $this->assignVariable(
 			$valueName,
-			$this->getIterableValueType($iterateeType),
-			$this->getIterableValueType($nativeIterateeType),
+			$originalScope->getIterableValueType($iterateeType),
+			$originalScope->getIterableValueType($nativeIterateeType),
 		);
 		if ($keyName !== null) {
-			$scope = $scope->enterForeachKey($iteratee, $keyName);
+			$scope = $scope->enterForeachKey($originalScope, $iteratee, $keyName);
 		}
 
 		return $scope;
 	}
 
-	public function enterForeachKey(Expr $iteratee, string $keyName): self
+	public function enterForeachKey(self $originalScope, Expr $iteratee, string $keyName): self
 	{
-		$iterateeType = $this->getType($iteratee);
-		$nativeIterateeType = $this->getNativeType($iteratee);
+		$iterateeType = $originalScope->getType($iteratee);
+		$nativeIterateeType = $originalScope->getNativeType($iteratee);
 		$scope = $this->assignVariable(
 			$keyName,
-			$this->getIterableKeyType($iterateeType),
-			$this->getIterableKeyType($nativeIterateeType),
+			$originalScope->getIterableKeyType($iterateeType),
+			$originalScope->getIterableKeyType($nativeIterateeType),
 		);
 
 		if ($iterateeType->isArray()->yes()) {
 			$scope = $scope->assignExpression(
 				new Expr\ArrayDimFetch($iteratee, new Variable($keyName)),
-				$this->getIterableValueType($iterateeType),
-				$this->getIterableValueType($nativeIterateeType),
+				$originalScope->getIterableValueType($iterateeType),
+				$originalScope->getIterableValueType($nativeIterateeType),
 			);
 		}
 

src/Analyser/NodeScopeResolver.php

@@ -835,20 +835,21 @@ private function processStmtNode(
 				$stmt->expr,
 				new Array_([]),
 			);
-			$inForeachScope = $scope;
 			if ($stmt->expr instanceof Variable && is_string($stmt->expr->name)) {
-				$inForeachScope = $this->processVarAnnotation($scope, [$stmt->expr->name], $stmt);
+				$scope = $this->processVarAnnotation($scope, [$stmt->expr->name], $stmt);
 			}
-			$nodeCallback(new InForeachNode($stmt), $inForeachScope);
+			$nodeCallback(new InForeachNode($stmt), $scope);
+			$originalScope = $scope;
 			$bodyScope = $scope;
 
 			if ($context->isTopLevel()) {
-				$bodyScope = $this->polluteScopeWithAlwaysIterableForeach ? $this->enterForeach($scope->filterByTruthyValue($arrayComparisonExpr), $stmt) : $this->enterForeach($scope, $stmt);
+				$originalScope = $this->polluteScopeWithAlwaysIterableForeach ? $scope->filterByTruthyValue($arrayComparisonExpr) : $scope;
+				$bodyScope = $this->enterForeach($originalScope, $originalScope, $stmt);
 				$count = 0;
 				do {
 					$prevScope = $bodyScope;
 					$bodyScope = $bodyScope->mergeWith($this->polluteScopeWithAlwaysIterableForeach ? $scope->filterByTruthyValue($arrayComparisonExpr) : $scope);
-					$bodyScope = $this->enterForeach($bodyScope, $stmt);
+					$bodyScope = $this->enterForeach($bodyScope, $originalScope, $stmt);
 					$bodyScopeResult = $this->processStmtNodes($stmt, $stmt->stmts, $bodyScope, static function (): void {
 					}, $context->enterDeep())->filterOutLoopExitPoints();
 					$bodyScope = $bodyScopeResult->getScope();
@@ -867,7 +868,7 @@ private function processStmtNode(
 			}
 
 			$bodyScope = $bodyScope->mergeWith($this->polluteScopeWithAlwaysIterableForeach ? $scope->filterByTruthyValue($arrayComparisonExpr) : $scope);
-			$bodyScope = $this->enterForeach($bodyScope, $stmt);
+			$bodyScope = $this->enterForeach($bodyScope, $originalScope, $stmt);
 			$finalScopeResult = $this->processStmtNodes($stmt, $stmt->stmts, $bodyScope, $nodeCallback, $context)->filterOutLoopExitPoints();
 			$finalScope = $finalScopeResult->getScope();
 			foreach ($finalScopeResult->getExitPointsByType(Continue_::class) as $continueExitPoint) {
@@ -4142,12 +4143,12 @@ private function processVarAnnotation(MutatingScope $scope, array $variableNames
 		return $scope;
 	}
 
-	private function enterForeach(MutatingScope $scope, Foreach_ $stmt): MutatingScope
+	private function enterForeach(MutatingScope $scope, MutatingScope $originalScope, Foreach_ $stmt): MutatingScope
 	{
 		if ($stmt->expr instanceof Variable && is_string($stmt->expr->name)) {
 			$scope = $this->processVarAnnotation($scope, [$stmt->expr->name], $stmt);
 		}
-		$iterateeType = $scope->getType($stmt->expr);
+		$iterateeType = $originalScope->getType($stmt->expr);
 		if (
 			($stmt->valueVar instanceof Variable && is_string($stmt->valueVar->name))
 			&& ($stmt->keyVar === null || ($stmt->keyVar instanceof Variable && is_string($stmt->keyVar->name)))
@@ -4157,6 +4158,7 @@ private function enterForeach(MutatingScope $scope, Foreach_ $stmt): MutatingSco
 				$keyVarName = $stmt->keyVar->name;
 			}
 			$scope = $scope->enterForeach(
+				$originalScope,
 				$stmt->expr,
 				$stmt->valueVar->name,
 				$keyVarName,
@@ -4180,7 +4182,7 @@ static function (): void {
 			if (
 				$stmt->keyVar instanceof Variable && is_string($stmt->keyVar->name)
 			) {
-				$scope = $scope->enterForeachKey($stmt->expr, $stmt->keyVar->name);
+				$scope = $scope->enterForeachKey($originalScope, $stmt->expr, $stmt->keyVar->name);
 				$vars[] = $stmt->keyVar->name;
 			} elseif ($stmt->keyVar !== null) {
 				$scope = $this->processAssignVar(

tests/PHPStan/Analyser/data/bug-4504.php

@@ -14,7 +14,7 @@ public function sayHello($models): void
 			assertType('Bug4504TypeInference\A', $v);
 		}
 
-		assertType('array{}|Iterator<mixed, Bug4504TypeInference\A>', $models);
+		assertType('Iterator<mixed, Bug4504TypeInference\A>', $models);
 	}
 
 }

tests/PHPStan/Analyser/data/bug-8924.php

@@ -13,3 +13,18 @@ function foo(array $array): void {
 		$array = null;
 	}
 }
+
+function makeValidNumbers(): array
+{
+	$validNumbers = [1, 2];
+	foreach ($validNumbers as $k => $v) {
+		assertType("non-empty-list<-2|-1|1|2|' 1'|' 2'>", $validNumbers);
+		assertType('0|1', $k);
+		assertType('1|2', $v);
+		$validNumbers[] = -$v;
+		$validNumbers[] = ' ' . (string)$v;
+		assertType("non-empty-list<-2|-1|1|2|' 1'|' 2'>", $validNumbers);
+	}
+
+	return $validNumbers;
+}