From 2ac81f954bc4933b51991217ec0556d3ff504b17 Mon Sep 17 00:00:00 2001
From: Mathieu Lemoine <mlemoine@mlemoine.name>
Date: Mon, 2 May 2016 11:12:26 -0400
Subject: [PATCH] Make failed autowiring error messages more explicit

---
 .../Compiler/AutowirePass.php                 | 41 +++++++++++++------
 .../Tests/Compiler/AutowirePassTest.php       | 21 ++++++++--
 2 files changed, 46 insertions(+), 16 deletions(-)

diff --git a/src/Symfony/Component/DependencyInjection/Compiler/AutowirePass.php b/src/Symfony/Component/DependencyInjection/Compiler/AutowirePass.php
index 4cef7df714..e4457d4608 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/AutowirePass.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/AutowirePass.php
@@ -105,7 +105,7 @@ class AutowirePass implements CompilerPassInterface
                     $this->populateAvailableTypes();
                 }
 
-                if (isset($this->types[$typeHint->name])) {
+                if (isset($this->types[$typeHint->name]) && !isset($this->notGuessableTypes[$typeHint->name])) {
                     $value = new Reference($this->types[$typeHint->name]);
                 } else {
                     try {
@@ -190,22 +190,26 @@ class AutowirePass implements CompilerPassInterface
      */
     private function set($type, $id)
     {
-        if (isset($this->definedTypes[$type]) || isset($this->notGuessableTypes[$type])) {
+        if (isset($this->definedTypes[$type])) {
             return;
         }
 
-        if (isset($this->types[$type])) {
-            if ($this->types[$type] === $id) {
-                return;
-            }
+        if (!isset($this->types[$type])) {
+            $this->types[$type] = $id;
 
-            unset($this->types[$type]);
+            return;
+        }
+
+        if ($this->types[$type] === $id) {
+            return;
+        }
+
+        if (!isset($this->notGuessableTypes[$type])) {
             $this->notGuessableTypes[$type] = true;
-
-            return;
+            $this->types[$type] = (array) $this->types[$type];
         }
 
-        $this->types[$type] = $id;
+        $this->types[$type][] = $id;
     }
 
     /**
@@ -220,8 +224,14 @@ class AutowirePass implements CompilerPassInterface
      */
     private function createAutowiredDefinition(\ReflectionClass $typeHint, $id)
     {
-        if (isset($this->notGuessableTypes[$typeHint->name]) || !$typeHint->isInstantiable()) {
-            throw new RuntimeException(sprintf('Unable to autowire argument of type "%s" for the service "%s".', $typeHint->name, $id));
+        if (isset($this->notGuessableTypes[$typeHint->name])) {
+            throw new RuntimeException(sprintf('Unable to autowire argument of type "%s" for the service "%s". Several services implementing this type have been declared: "%s".', $typeHint->name, $id, implode('", "', $this->types[$typeHint->name])));
+        }
+
+        $noAvailableDefinitionMessage = sprintf('Unable to autowire argument of type "%s" for the service "%s". This type cannot be instantiated automatically and no service implementing this type is declared.', $typeHint->name, $id);
+
+        if (!$typeHint->isInstantiable()) {
+            throw new RuntimeException($noAvailableDefinitionMessage);
         }
 
         $argumentId = sprintf('autowired.%s', $typeHint->name);
@@ -230,7 +240,12 @@ class AutowirePass implements CompilerPassInterface
         $argumentDefinition->setPublic(false);
 
         $this->populateAvailableType($argumentId, $argumentDefinition);
-        $this->completeDefinition($argumentId, $argumentDefinition);
+
+        try {
+            $this->completeDefinition($argumentId, $argumentDefinition);
+        } catch (RuntimeException $e) {
+            throw new RuntimeException($noAvailableDefinitionMessage, 0, $e);
+        }
 
         return new Reference($argumentId);
     }
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Compiler/AutowirePassTest.php b/src/Symfony/Component/DependencyInjection/Tests/Compiler/AutowirePassTest.php
index 1c61f05b0b..6098d9a913 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Compiler/AutowirePassTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Compiler/AutowirePassTest.php
@@ -103,7 +103,7 @@ class AutowirePassTest extends \PHPUnit_Framework_TestCase
 
     /**
      * @expectedException \Symfony\Component\DependencyInjection\Exception\RuntimeException
-     * @expectedExceptionMessage Unable to autowire argument of type "Symfony\Component\DependencyInjection\Tests\Compiler\CollisionInterface" for the service "a".
+     * @expectedExceptionMessage Unable to autowire argument of type "Symfony\Component\DependencyInjection\Tests\Compiler\CollisionInterface" for the service "a". Several services implementing this type have been declared: "c1", "c2".
      */
     public function testTypeCollision()
     {
@@ -120,7 +120,7 @@ class AutowirePassTest extends \PHPUnit_Framework_TestCase
 
     /**
      * @expectedException \Symfony\Component\DependencyInjection\Exception\RuntimeException
-     * @expectedExceptionMessage Unable to autowire argument of type "Symfony\Component\DependencyInjection\Tests\Compiler\Foo" for the service "a".
+     * @expectedExceptionMessage Unable to autowire argument of type "Symfony\Component\DependencyInjection\Tests\Compiler\Foo" for the service "a". Several services implementing this type have been declared: "a1", "a2".
      */
     public function testTypeNotGuessable()
     {
@@ -137,7 +137,7 @@ class AutowirePassTest extends \PHPUnit_Framework_TestCase
 
     /**
      * @expectedException \Symfony\Component\DependencyInjection\Exception\RuntimeException
-     * @expectedExceptionMessage Unable to autowire argument of type "Symfony\Component\DependencyInjection\Tests\Compiler\A" for the service "a".
+     * @expectedExceptionMessage Unable to autowire argument of type "Symfony\Component\DependencyInjection\Tests\Compiler\A" for the service "a". Several services implementing this type have been declared: "a1", "a2".
      */
     public function testTypeNotGuessableWithSubclass()
     {
@@ -207,6 +207,21 @@ class AutowirePassTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals(__NAMESPACE__.'\Lille', $lilleDefinition->getClass());
     }
 
+    /**
+     * @expectedException \Symfony\Component\DependencyInjection\Exception\RuntimeException
+     * @expectedExceptionMessage Unable to autowire argument of type "Symfony\Component\DependencyInjection\Tests\Compiler\CollisionInterface" for the service "a". This type cannot be instantiated automatically and no service implementing this type is declared.
+     */
+    public function testCreateNonInstanciable()
+    {
+        $container = new ContainerBuilder();
+
+        $aDefinition = $container->register('a', __NAMESPACE__.'\CannotBeAutowired');
+        $aDefinition->setAutowired(true);
+
+        $pass = new AutowirePass();
+        $pass->process($container);
+    }
+
     public function testResolveParameter()
     {
         $container = new ContainerBuilder();