Extend trait context detection to cover self-typed variables and fix multiple method names

- Add isExpressionDependentOnTraitContext() that checks both AST-level
  ($this, self::, static::) and type-level (object type matches using class)
  dependency on trait context
- Fix method_exists handling to support multiple constant method names
  (e.g. 'foo'|'bar') instead of requiring exactly one
- Add null check for getTraitReflection()
- Update ConstantConditionRuleHelper with same type-level check
- Fix testBug7599: method_exists($enum, 'barMethod') where $enum is
  typed as self in a trait should not report errors

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: phpstan-bot

src/Rules/Comparison/ConstantConditionRuleHelper.php

@@ -67,6 +67,16 @@ private function shouldSkip(Scope $scope, Expr $expr): bool
 					if (ExpressionDependsOnThisHelper::isExpressionDependentOnThis($arg->value)) {
 						return true;
 					}
+
+					$classReflection = $scope->getClassReflection();
+					if ($classReflection !== null) {
+						$argType = $this->treatPhpDocTypesAsCertain ? $scope->getType($arg->value) : $scope->getNativeType($arg->value);
+						foreach ($argType->getObjectClassNames() as $className) {
+							if ($className === $classReflection->getName()) {
+								return true;
+							}
+						}
+					}
 				}
 			}
 		}

src/Rules/Comparison/ImpossibleCheckTypeHelper.php

@@ -199,17 +199,22 @@ public function findSpecifiedType(
 				} elseif ($functionName === 'method_exists' && $argsCount >= 2) {
 					$objectArg = $args[0]->value;
 
-					if ($scope->isInTrait() && ExpressionDependsOnThisHelper::isExpressionDependentOnThis($objectArg)) {
+					if ($this->isExpressionDependentOnTraitContext($scope, $objectArg)) {
 						$traitReflection = $scope->getTraitReflection();
+						if ($traitReflection === null) {
+							return null;
+						}
 						$methodArgValue = $args[1]->value;
 						$methodArgType = $this->treatPhpDocTypesAsCertain ? $scope->getType($methodArgValue) : $scope->getNativeType($methodArgValue);
 						$constantMethodNames = $methodArgType->getConstantStrings();
-						if (
-							count($constantMethodNames) !== 1
-							|| !$traitReflection->hasNativeMethod($constantMethodNames[0]->getValue())
-						) {
+						if (count($constantMethodNames) === 0) {
 							return null;
 						}
+						foreach ($constantMethodNames as $constantMethodName) {
+							if (!$traitReflection->hasNativeMethod($constantMethodName->getValue())) {
+								return null;
+							}
+						}
 					}
 					$objectType = $this->treatPhpDocTypesAsCertain ? $scope->getType($objectArg) : $scope->getNativeType($objectArg);
 
@@ -323,7 +328,7 @@ public function findSpecifiedType(
 				continue;
 			}
 
-			if ($scope->isInTrait() && ExpressionDependsOnThisHelper::isExpressionDependentOnThis($sureType[0])) {
+			if ($this->isExpressionDependentOnTraitContext($scope, $sureType[0])) {
 				$results[] = TrinaryLogic::createMaybe();
 				continue;
 			}
@@ -354,7 +359,7 @@ public function findSpecifiedType(
 				continue;
 			}
 
-			if ($scope->isInTrait() && ExpressionDependsOnThisHelper::isExpressionDependentOnThis($sureNotType[0])) {
+			if ($this->isExpressionDependentOnTraitContext($scope, $sureNotType[0])) {
 				$results[] = TrinaryLogic::createMaybe();
 				continue;
 			}
@@ -379,6 +384,31 @@ public function findSpecifiedType(
 		return $result->maybe() ? null : $result->yes();
 	}
 
+	private function isExpressionDependentOnTraitContext(Scope $scope, Expr $expr): bool
+	{
+		if (!$scope->isInTrait()) {
+			return false;
+		}
+
+		if (ExpressionDependsOnThisHelper::isExpressionDependentOnThis($expr)) {
+			return true;
+		}
+
+		$classReflection = $scope->getClassReflection();
+		if ($classReflection === null) {
+			return false;
+		}
+
+		$type = $this->treatPhpDocTypesAsCertain ? $scope->getType($expr) : $scope->getNativeType($expr);
+		foreach ($type->getObjectClassNames() as $className) {
+			if ($className === $classReflection->getName()) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
 	private static function isSpecified(Scope $scope, Expr $node, Expr $expr): bool
 	{
 		if ($expr === $node) {

tests/PHPStan/Rules/Comparison/ImpossibleCheckTypeFunctionCallRuleTest.php

@@ -1208,16 +1208,7 @@ public function testBug13023(): void
 	public function testBug7599(): void
 	{
 		$this->treatPhpDocTypesAsCertain = true;
-		$this->analyse([__DIR__ . '/data/bug-7599.php'], [
-			[
-				'Call to function method_exists() with Bug7599\SecondEnum::Baz and \'barMethod\' will always evaluate to true.',
-				13,
-			],
-			[
-				'Call to function method_exists() with Bug7599\TestEnum::Bar|Bug7599\TestEnum::Foo and \'barMethod\' will always evaluate to false.',
-				13,
-			],
-		]);
+		$this->analyse([__DIR__ . '/data/bug-7599.php'], []);
 	}
 
 	public function testBug9095(): void