Issue #3125234 by martin107, longwave: ProxyBuilder compatibility with Symfony 5

(cherry picked from commit 66e8d084)

core/lib/Drupal/Component/ProxyBuilder/ProxyBuilder.php

@@ -236,6 +236,9 @@ protected function buildMethod(\ReflectionMethod $reflection_method) {
 
     $signature_line .= implode(', ', $parameters);
     $signature_line .= ')';
+    if ($reflection_method->hasReturnType()) {
+      $signature_line .= ': ' . $reflection_method->getReturnType()->getName();
+    }
 
     $output = $signature_line . "\n{\n";
 
@@ -265,6 +268,9 @@ protected function buildParameter(\ReflectionParameter $parameter) {
     elseif ($class = $parameter->getClass()) {
       $parameter_string .= '\\' . $class->getName() . ' ';
     }
+    elseif ($parameter->hasType()) {
+      $parameter_string .= $parameter->getType()->getName() . ' ';
+    }
 
     if ($parameter->isPassedByReference()) {
       $parameter_string .= '&';

core/tests/Drupal/Tests/Component/ProxyBuilder/ProxyBuilderTest.php

@@ -133,8 +133,8 @@ public function testBuildComplexMethod() {
 /**
  * {@inheritdoc}
  */
-public function complexMethod($parameter, callable $function, \Drupal\Tests\Component\ProxyBuilder\TestServiceNoMethod $test_service = NULL, array &$elements = array (
-))
+public function complexMethod(string $parameter, callable $function, \Drupal\Tests\Component\ProxyBuilder\TestServiceNoMethod $test_service = NULL, array &$elements = array (
+)): array
 {
     return $this->lazyLoadItself()->complexMethod($parameter, $function, $test_service, $elements);
 }
@@ -381,7 +381,7 @@ public function methodWithParameter($parameter) {
 
 class TestServiceComplexMethod {
 
-  public function complexMethod($parameter, callable $function, TestServiceNoMethod $test_service = NULL, array &$elements = []) {
+  public function complexMethod(string $parameter, callable $function, TestServiceNoMethod $test_service = NULL, array &$elements = []): array {
 
   }