[DI] Improve exception message on missing $ of named argument

Author: jschaedl

src/Symfony/Component/DependencyInjection/Compiler/ResolveNamedArgumentsPass.php

@@ -53,6 +53,10 @@ protected function processValue($value, $isRoot = false)
                     $parameters = $r->getParameters();
                 }
 
+                if (isset($key[0]) && '$' !== $key[0] && !class_exists($key)) {
+                    throw new InvalidArgumentException(sprintf('Invalid service "%s": did you forget to add the "$" prefix to argument "%s"?', $this->currentId, $key));
+                }
+
                 if (isset($key[0]) && '$' === $key[0]) {
                     foreach ($parameters as $j => $p) {
                         if ($key === '$'.$p->name) {

src/Symfony/Component/DependencyInjection/Tests/Compiler/ResolveNamedArgumentsPassTest.php

@@ -149,6 +149,21 @@ public function testTypedArgument()
         $this->assertEquals([new Reference('foo'), '123'], $definition->getArguments());
     }
 
+    /**
+     * @expectedException \Symfony\Component\DependencyInjection\Exception\InvalidArgumentException
+     * @expectedExceptionMessage Invalid service "Symfony\Component\DependencyInjection\Tests\Fixtures\NamedArgumentsDummy": did you forget to add the "$" prefix to argument "apiKey"?
+     */
+    public function testTypedArgumentWithMissingDollar()
+    {
+        $container = new ContainerBuilder();
+
+        $definition = $container->register(NamedArgumentsDummy::class, NamedArgumentsDummy::class);
+        $definition->setArgument('apiKey', '123');
+
+        $pass = new ResolveNamedArgumentsPass();
+        $pass->process($container);
+    }
+
     public function testResolvesMultipleArgumentsOfTheSameType()
     {
         $container = new ContainerBuilder();