feature #20648 [DependencyInjection] Added a shortcut method for autowired definitions (wouterj)

This PR was merged into the 3.3-dev branch.

Discussion
----------

[DependencyInjection] Added a shortcut method for autowired definitions

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | todo

This is a simple proposal to make adding autowired definitions to the `ContainerBuilder` a little easier. Registering autowired services in PHP code was quite verbose at the moment, while the whole point of autowiring is quick service registration.

**Before**
```php
$container->register('app.twig_extension', AppExtension::class)
    ->setAutowired(true)
    ->addTag('twig.extension')
;
```

**After**
```php
$container->autowire('app.twig_extension', AppExtension::class)
    ->addTag('twig.extension')
;
```

With https://github.com/symfony/symfony/pull/20264, this will be even nicer:
```php
$container->autowire(AppExtension::class)
    ->addTag('twig.extension')
;
```

Commits
-------

6ef4ce8 Added a shortcut method for autowired definitions

src/Symfony/Component/DependencyInjection/ContainerBuilder.php

@@ -710,6 +710,22 @@ class ContainerBuilder extends Container implements TaggedContainerInterface
         return $this->setDefinition($id, new Definition($class));
     }
 
+    /**
+     * Registers an autowired service definition.
+     *
+     * This method implements a shortcut for using setDefinition() with
+     * an autowired definition.
+     *
+     * @param string      $id    The service identifier
+     * @param null|string $class The service class
+     *
+     * @return Definition The created definition
+     */
+    public function autowire($id, $class = null)
+    {
+        return $this->setDefinition($id, (new Definition($class))->setAutowired(true));
+    }
+
     /**
      * Adds the service definitions.
      *

src/Symfony/Component/DependencyInjection/Tests/ContainerBuilderTest.php

@@ -82,6 +82,15 @@ class ContainerBuilderTest extends \PHPUnit_Framework_TestCase
         $this->assertInstanceOf('Symfony\Component\DependencyInjection\Definition', $builder->getDefinition('foo'), '->register() returns the newly created Definition instance');
     }
 
+    public function testAutowire()
+    {
+        $builder = new ContainerBuilder();
+        $builder->autowire('foo', 'Bar\FooClass');
+
+        $this->assertTrue($builder->hasDefinition('foo'), '->autowire() registers a new service definition');
+        $this->assertTrue($builder->getDefinition('foo')->isAutowired(), '->autowire() creates autowired definitions');
+    }
+
     public function testHas()
     {
         $builder = new ContainerBuilder();