Fixed false positive about undefined method guarded with method_exists

Author: ondrejmirtes

src/Rules/Methods/CallMethodsRule.php

@@ -58,7 +58,7 @@ public function processNode(Node $node, Scope $scope): array
 	 */
 	private function processSingleMethodCall(Scope $scope, MethodCall $node, string $methodName): array
 	{
-		[$errors, $methodReflection] = $this->methodCallCheck->check($scope, $methodName, $node->var);
+		[$errors, $methodReflection] = $this->methodCallCheck->check($scope, $methodName, $node->var, $node->name);
 		if ($methodReflection === null) {
 			return $errors;
 		}

src/Rules/Methods/MethodCallCheck.php

@@ -2,7 +2,10 @@
 
 namespace PHPStan\Rules\Methods;
 
+use PhpParser\Node\Arg;
 use PhpParser\Node\Expr;
+use PhpParser\Node\Identifier;
+use PhpParser\Node\Name\FullyQualified;
 use PHPStan\Analyser\NullsafeOperatorHelper;
 use PHPStan\Analyser\Scope;
 use PHPStan\Internal\SprintfHelper;
@@ -38,6 +41,7 @@ public function check(
 		Scope $scope,
 		string $methodName,
 		Expr $var,
+		Identifier|Expr $astName,
 	): array
 	{
 		$typeResult = $this->ruleLevelHelper->findTypeToCheck(
@@ -107,6 +111,17 @@ public function check(
 				}
 			}
 
+			if ($astName instanceof Expr) {
+				$methodExistsExpr = new Expr\FuncCall(new FullyQualified('method_exists'), [
+					new Arg($var),
+					new Arg($astName),
+				]);
+
+				if ($scope->getType($methodExistsExpr)->isTrue()->yes()) {
+					return [[], null];
+				}
+			}
+
 			return [
 				[
 					RuleErrorBuilder::message(sprintf(

src/Rules/Methods/MethodCallableRule.php

@@ -44,7 +44,7 @@ public function processNode(Node $node, Scope $scope): array
 
 		$methodNameName = $methodName->toString();
 
-		[$errors, $methodReflection] = $this->methodCallCheck->check($scope, $methodNameName, $node->getVar());
+		[$errors, $methodReflection] = $this->methodCallCheck->check($scope, $methodNameName, $node->getVar(), $node->getName());
 		if ($methodReflection === null) {
 			return $errors;
 		}

src/Type/Php/MethodExistsTypeSpecifyingExtension.php

@@ -3,6 +3,7 @@
 namespace PHPStan\Type\Php;
 
 use PhpParser\Node\Expr\FuncCall;
+use PhpParser\Node\Name\FullyQualified;
 use PHPStan\Analyser\Scope;
 use PHPStan\Analyser\SpecifiedTypes;
 use PHPStan\Analyser\TypeSpecifier;
@@ -11,6 +12,7 @@
 use PHPStan\Reflection\FunctionReflection;
 use PHPStan\Type\Accessory\HasMethodType;
 use PHPStan\Type\ClassStringType;
+use PHPStan\Type\Constant\ConstantBooleanType;
 use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\FunctionTypeSpecifyingExtension;
 use PHPStan\Type\IntersectionType;
@@ -48,7 +50,12 @@ public function specifyTypes(
 	{
 		$methodNameType = $scope->getType($node->getArgs()[1]->value);
 		if (!$methodNameType instanceof ConstantStringType) {
-			return new SpecifiedTypes([], []);
+			return $this->typeSpecifier->create(
+				new FuncCall(new FullyQualified('method_exists'), $node->getRawArgs()),
+				new ConstantBooleanType(true),
+				$context,
+				$scope,
+			);
 		}
 
 		$objectType = $scope->getType($node->getArgs()[0]->value);

tests/PHPStan/Rules/Methods/CallMethodsRuleTest.php

@@ -3587,4 +3587,14 @@ public function testDynamicCall(): void
 		]);
 	}
 
+	public function testBu12793(): void
+	{
+		$this->checkThisOnly = false;
+		$this->checkNullables = true;
+		$this->checkUnionTypes = true;
+		$this->checkExplicitMixed = true;
+
+		$this->analyse([__DIR__ . '/data/bug-12793.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Methods/data/bug-12793.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace Bug12793;
+
+class Service
+{
+	protected function defaults(Model $model): void
+	{
+		$columns = [
+			'getCreatedByColumn',
+			'getUpdatedByColumn',
+			'getDeletedByColumn',
+			'getCreatedAtColumn',
+			'getUpdatedAtColumn',
+			'getDeletedAtColumn',
+		];
+
+		foreach ($columns as $column) {
+			if (method_exists($model, $column)) {
+				$model->{$column}();
+			}
+		}
+	}
+}
+
+class Model {}