minor #14470 [DependencyInjection] Removed extra strtolower calls (dosten)

This PR was squashed before being merged into the 2.3 branch (closes #14470).

Discussion
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[DependencyInjection] Removed extra strtolower calls

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

`Alias` already lowercase the `$id` in the constructor. Using `ContainerBuilder::hasAlias()` and `ContainerBuilder::hasDefinition()` inside the code makes an extra strtolower call.

Commits
-------

3bfbf45 [DependencyInjection] Removed extra strtolower calls

Author: fabpot

ContainerBuilder.php

@@ -470,7 +470,7 @@ public function get($id, $invalidBehavior = ContainerInterface::EXCEPTION_ON_INV
             throw new LogicException(sprintf('The service "%s" has a circular reference to itself.', $id));
         }
 
-        if (!$this->hasDefinition($id) && isset($this->aliasDefinitions[$id])) {
+        if (!array_key_exists($id, $this->definitions) && isset($this->aliasDefinitions[$id])) {
             return $this->get($this->aliasDefinitions[$id]);
         }
 
@@ -686,7 +686,7 @@ public function setAlias($alias, $id)
             throw new InvalidArgumentException('$id must be a string, or an Alias object.');
         }
 
-        if ($alias === strtolower($id)) {
+        if ($alias === (string) $id) {
             throw new InvalidArgumentException(sprintf('An alias can not reference itself, got a circular reference on "%s".', $alias));
         }
 
@@ -748,7 +748,7 @@ public function getAlias($id)
     {
         $id = strtolower($id);
 
-        if (!$this->hasAlias($id)) {
+        if (!isset($this->aliasDefinitions[$id])) {
             throw new InvalidArgumentException(sprintf('The service alias "%s" does not exist.', $id));
         }
 
@@ -866,7 +866,7 @@ public function getDefinition($id)
     {
         $id = strtolower($id);
 
-        if (!$this->hasDefinition($id)) {
+        if (!array_key_exists($id, $this->definitions)) {
             throw new InvalidArgumentException(sprintf('The service definition "%s" does not exist.', $id));
         }
 
@@ -888,8 +888,10 @@ public function getDefinition($id)
      */
     public function findDefinition($id)
     {
-        while ($this->hasAlias($id)) {
-            $id = (string) $this->getAlias($id);
+        $id = strtolower($id);
+
+        while (isset($this->aliasDefinitions[$id])) {
+            $id = (string) $this->aliasDefinitions[$id];
         }
 
         return $this->getDefinition($id);

Tests/ContainerBuilderTest.php

@@ -189,6 +189,13 @@ public function testAliases()
         $this->assertTrue($builder->has('bar'), '->setAlias() defines a new service');
         $this->assertTrue($builder->get('bar') === $builder->get('foo'), '->setAlias() creates a service that is an alias to another one');
 
+        try {
+            $builder->setAlias('foobar', 'foobar');
+            $this->fail('->setAlias() throws an InvalidArgumentException if the alias references itself');
+        } catch (\InvalidArgumentException $e) {
+            $this->assertEquals('An alias can not reference itself, got a circular reference on "foobar".', $e->getMessage(), '->setAlias() throws an InvalidArgumentException if the alias references itself');
+        }
+
         try {
             $builder->getAlias('foobar');
             $this->fail('->getAlias() throws an InvalidArgumentException if the alias does not exist');