Improve exception messages.

Author: jakzal

Tests/Mapping/Loader/YamlFileLoaderTest.php

@@ -31,15 +31,26 @@ public function testLoadClassMetadataReturnsFalseIfEmpty()
         $this->assertFalse($loader->loadClassMetadata($metadata));
     }
 
-    public function testLoadClassMetadataThrowsExceptionIfNotAnArray()
+    /**
+     * @dataProvider provideInvalidYamlFiles
+     * @expectedException \InvalidArgumentException
+     */
+    public function testInvalidYamlFiles($path)
     {
-        $loader = new YamlFileLoader(__DIR__.'/nonvalid-mapping.yml');
+        $loader = new YamlFileLoader(__DIR__.'/'.$path);
         $metadata = new ClassMetadata('Symfony\Component\Validator\Tests\Fixtures\Entity');
 
-        $this->setExpectedException('\InvalidArgumentException');
         $loader->loadClassMetadata($metadata);
     }
 
+    public function provideInvalidYamlFiles()
+    {
+        return array(
+            array('nonvalid-mapping.yml'),
+            array('bad-format.yml'),
+        );
+    }
+
     /**
      * @see https://github.com/symfony/symfony/pull/12158
      */

Tests/Mapping/Loader/bad-format.yml

@@ -0,0 +1,9 @@
+namespaces:
+	custom: Symfony\Component\Validator\Tests\Fixtures\
+
+Symfony\Component\Validator\Tests\Fixtures\Entity:
+	constraints:
+		# Custom constraint
+		- Symfony\Component\Validator\Tests\Fixtures\ConstraintA: ~
+		# Custom constraint with namespaces prefix
+		- "custom:ConstraintB": ~