[Debug] made Debug find FQCN automatically based on well-known autoloaders

src/Symfony/Component/ClassLoader/DebugClassLoader.php

@@ -39,6 +39,16 @@ class DebugClassLoader
         $this->classFinder = $classFinder;
     }
 
+    /**
+     * Gets the wrapped class loader.
+     *
+     * @return object a class loader instance
+     */
+    public function getClassLoader()
+    {
+        return $this->classFinder;
+    }
+
     /**
      * Replaces all autoloaders implementing a findFile method by a DebugClassLoader wrapper.
      */

src/Symfony/Component/Debug/CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+2.4.0
+-----
+
+ * improved error messages for not found classes and functions
+
 2.3.0
 -----
 

src/Symfony/Component/Debug/ErrorHandler.php

@@ -16,6 +16,9 @@ use Symfony\Component\Debug\Exception\ClassNotFoundException;
 use Symfony\Component\Debug\Exception\ContextErrorException;
 use Symfony\Component\Debug\Exception\FatalErrorException;
 use Symfony\Component\Debug\Exception\UndefinedFunctionException;
+use Composer\Autoload\ClassLoader as ComposerClassLoader;
+use Symfony\Component\ClassLoader as SymfonyClassLoader;
+use Symfony\Component\ClassLoader\DebugClassLoader;
 
 /**
  * ErrorHandler.
@@ -288,7 +291,7 @@ class ErrorHandler
                 );
             }
 
-            if ($classes = $this->getUseStatementSuggestions($className)) {
+            if ($classes = $this->getClassCandidates($className)) {
                 $message .= sprintf(' Perhaps you need to add a use statement for one of the following class: %s.', implode(', ', $classes));
             }
 
@@ -296,15 +299,82 @@ class ErrorHandler
         }
     }
 
-    protected function getUseStatementSuggestions($class)
+    /**
+     * Tries to guess the full namespace for a given class name.
+     *
+     * By default, it looks for PSR-0 classes registered via a Symfony or a Composer
+     * autoloader (that should cover all common cases).
+     *
+     * @param string $class A class name (without its namespace)
+     *
+     * @return array An array of possible fully qualified class names
+     */
+    private function getClassCandidates($class)
     {
-        $classNameToUseStatementSuggestions = array(
-            'Request'  => array('Symfony\Component\HttpFoundation\Request'),
-            'Response' => array('Symfony\Component\HttpFoundation\Response'),
-        );
+        if (!is_array($functions = spl_autoload_functions())) {
+            return array();
+        }
 
-        if (isset($classNameToUseStatementSuggestions[$class])) {
-            return $classNameToUseStatementSuggestions[$class];
+        // find Symfony and Composer autoloaders
+        $classes = array();
+        foreach ($functions as $function) {
+            if (!is_array($function)) {
+                continue;
+            }
+
+            // get class loaders wrapped by DebugClassLoader
+            if ($function[0] instanceof DebugClassLoader && method_exists($function[0], 'getClassLoader')) {
+                $function[0] = $function[0]->getClassLoader();
+            }
+
+            if ($function[0] instanceof ComposerClassLoader || $function[0] instanceof SymfonyClassLoader) {
+                foreach ($function[0]->getPrefixes() as $paths) {
+                    foreach ($paths as $path) {
+                        $classes = array_merge($classes, $this->findClassInPath($function[0], $path, $class));
+                    }
+                }
+            }
+        }
+
+        return $classes;
+    }
+
+    private function findClassInPath($loader, $path, $class)
+    {
+        if (!$path = realpath($path)) {
+            continue;
+        }
+
+        $classes = array();
+        $filename = $class.'.php';
+        foreach (new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($path), \RecursiveIteratorIterator::LEAVES_ONLY) as $file) {
+            if ($filename == $file->getFileName() && $class = $this->convertFileToClass($loader, $path, $file->getPathName())) {
+                $classes[] = $class;
+            }
+        }
+
+        return $classes;
+    }
+
+    private function convertFileToClass($loader, $path, $file)
+    {
+        // We cannot use the autoloader here as most of them use require; but if the class
+        // is not found, the new autoloader call will require the file again leading to a
+        // "cannot redeclare class" error.
+        require_once $file;
+
+        $file = str_replace(array($path.'/', '.php'), array('', ''), $file);
+
+        // is it a namespaced class?
+        $class = str_replace('/', '\\', $file);
+        if (class_exists($class, false) || interface_exists($class, false) || (function_exists('trait_exists') && trait_exists($class, false))) {
+            return $class;
+        }
+
+        // is it a PEAR-like class name instead?
+        $class = str_replace('/', '_', $file);
+        if (class_exists($class, false) || interface_exists($class, false) || (function_exists('trait_exists') && trait_exists($class, false))) {
+            return $class;
         }
     }
 }

src/Symfony/Component/Debug/Tests/ErrorHandlerTest.php

@@ -119,18 +119,27 @@ class ErrorHandlerTest extends \PHPUnit_Framework_TestCase
                     'type' => 1,
                     'line' => 12,
                     'file' => 'foo.php',
-                    'message' => 'Class "Request" not found',
+                    'message' => 'Class "UndefinedFunctionException" not found',
                 ),
-                'Attempted to load class "Request" from the global namespace in foo.php line 12. Did you forget a use statement for this class? Perhaps you need to add a use statement for one of the following class: Symfony\Component\HttpFoundation\Request.',
+                'Attempted to load class "UndefinedFunctionException" from the global namespace in foo.php line 12. Did you forget a use statement for this class? Perhaps you need to add a use statement for one of the following class: Symfony\Component\Debug\Exception\UndefinedFunctionException.',
             ),
             array(
                 array(
                     'type' => 1,
                     'line' => 12,
                     'file' => 'foo.php',
-                    'message' => 'Class "Foo\\Bar\\Request" not found',
+                    'message' => 'Class "PEARClass" not found',
                 ),
-                'Attempted to load class "Request" from namespace "Foo\Bar" in foo.php line 12. Do you need to "use" it from another namespace? Perhaps you need to add a use statement for one of the following class: Symfony\Component\HttpFoundation\Request.',
+                'Attempted to load class "PEARClass" from the global namespace in foo.php line 12. Did you forget a use statement for this class? Perhaps you need to add a use statement for one of the following class: Symfony_Component_Debug_Tests_Fixtures_PEARClass.',
+            ),
+            array(
+                array(
+                    'type' => 1,
+                    'line' => 12,
+                    'file' => 'foo.php',
+                    'message' => 'Class "Foo\\Bar\\UndefinedFunctionException" not found',
+                ),
+                'Attempted to load class "UndefinedFunctionException" from namespace "Foo\Bar" in foo.php line 12. Do you need to "use" it from another namespace? Perhaps you need to add a use statement for one of the following class: Symfony\Component\Debug\Exception\UndefinedFunctionException.',
             ),
         );
     }

src/Symfony/Component/Debug/Tests/Fixtures/PEARClass.php

@@ -0,0 +1,5 @@
+<?php
+
+class Symfony_Component_Debug_Tests_Fixtures_PEARClass
+{
+}