feature #28412 [PhpUnitBridge] enable DebugClassLoader by default (ni…

…colas-grekas)

This PR was merged into the 4.2-dev branch.

Discussion
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[PhpUnitBridge] enable DebugClassLoader by default

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | symfony/symfony-docs#10360

With this PR, the phpunit-bridge will enable `DebugClassLoader` by default, making it do its job: throw deprecation notices at autoloading time. On top of #28329, this made me spot some glitches in the code base, fixed here also.

This can be disabled by configuring the listener in `phpunit.xml.dist` files, adding `<element key="debug-class-loader"><integer>0</integer></element>` next to `<element key="time-sensitive">...`.

Commits
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2fb11fce28 [PhpUnitBridge] enable DebugClassLoader by default

Legacy/SymfonyTestsListenerTrait.php

@@ -18,6 +18,7 @@
 use PHPUnit\Util\Blacklist;
 use Symfony\Bridge\PhpUnit\ClockMock;
 use Symfony\Bridge\PhpUnit\DnsMock;
+use Symfony\Component\Debug\DebugClassLoader;
 
 /**
  * PHP 5.3 compatible trait-like shared implementation.
@@ -52,6 +53,8 @@ public function __construct(array $mockedNamespaces = array())
             Blacklist::$blacklistedClassNames['\Symfony\Bridge\PhpUnit\Legacy\SymfonyTestsListenerTrait'] = 2;
         }
 
+        $enableDebugClassLoader = \class_exists('Symfony\Component\Debug\DebugClassLoader');
+
         foreach ($mockedNamespaces as $type => $namespaces) {
             if (!\is_array($namespaces)) {
                 $namespaces = array($namespaces);
@@ -66,6 +69,12 @@ public function __construct(array $mockedNamespaces = array())
                     DnsMock::register($ns.'\DummyClass');
                 }
             }
+            if ('debug-class-loader' === $type) {
+                $enableDebugClassLoader = $namespaces && $namespaces[0];
+            }
+        }
+        if ($enableDebugClassLoader) {
+            DebugClassLoader::enable();
         }
         if (self::$globallyEnabled) {
             $this->state = -2;