Add NoFragmentDefined

README.md

@@ -44,10 +44,12 @@ The following example demonstrates how a closure can be used to synthesize multi
 $config = $config->synthesize('core', function(array $fragments) {
 
 	return call_user_func_array('ICanBoogie\array_merge_recursive', $fragments);
-	
+
 });
 ```
 
+The exception [NoFragmentDefined][] is thrown when no fragment of a specified type is defined.
+
 
 
 
@@ -220,5 +222,6 @@ The package is continuously tested by [Travis CI](http://about.travis-ci.org/).
 [icanboogie/event]: https://github.com/ICanBoogie/Event
 [ICanBoogie]:       https://github.com/ICanBoogie
 
-[Config]:     http://api.icanboogie.org/config/1.1/class-ICanBoogie.Config.html
-[Storage]:    http://api.icanboogie.org/storage/2.0/class-ICanBoogie.Storage.Storage.html
+[Config]:            https://icanboogie.org/api/config/1.1/class-ICanBoogie.Config.html
+[Storage]:           https://icanboogie.org/api/storage/2.0/class-ICanBoogie.Storage.Storage.html
+[NoFragmentDefined]: https://icanboogie.org/api/config/master/class-ICanBoogie.NoFragmentDefined.html

lib/Config.php

@@ -11,6 +11,7 @@
 
 namespace ICanBoogie;
 
+use ICanBoogie\Config\NoFragmentDefined;
 use ICanBoogie\Storage\Storage;
 
 /**
@@ -289,13 +290,19 @@ public function synthesize($name, $synthesizer, $from = null)
 		return $this->synthesized[$name] = $config;
 	}
 
+	/**
+	 * @param string $name
+	 * @param callable $synthesizer
+	 *
+	 * @return mixed
+	 */
 	private function synthesize_for_real($name, $synthesizer)
 	{
 		$fragments = $this->get_fragments($name);
 
 		if (!$fragments)
 		{
-			return null;
+			throw new NoFragmentDefined($name);
 		}
 
 		if ($synthesizer == 'merge')

lib/Config/Exception.php

@@ -0,0 +1,20 @@
+<?php
+
+/*
+ * This file is part of the ICanBoogie package.
+ *
+ * (c) Olivier Laviale <olivier.laviale@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace ICanBoogie\Config;
+
+/**
+ * Config exceptions implement this interface so that they can be easily recognized.
+ */
+interface Exception
+{
+
+}

lib/Config/NoFragmentDefined.php

@@ -0,0 +1,37 @@
+<?php
+
+/*
+ * This file is part of the ICanBoogie package.
+ *
+ * (c) Olivier Laviale <olivier.laviale@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace ICanBoogie\Config;
+
+/**
+ * Exception throw when no fragment of a specified type is defined.
+ */
+class NoFragmentDefined extends \LogicException implements Exception
+{
+	/**
+	 * @param string $fragment
+	 * @param \Exception|null $previous
+	 */
+	public function __construct($fragment, \Exception $previous = null)
+	{
+		parent::__construct($this->format_message($fragment), 500, $previous);
+	}
+
+	/**
+	 * @param $fragment
+	 *
+	 * @return string
+	 */
+	protected function format_message($fragment)
+	{
+		return "There is not `$fragment` fragment defined.";
+	}
+}

tests/ConfigTest.php

@@ -27,10 +27,13 @@ static public function setupBeforeClass()
 		];
 	}
 
-	public function test_synthesize_undefined()
+	/**
+	 * @expectedException \ICanBoogie\Config\NoFragmentDefined
+	 */
+	public function test_should_throw_exception_on_undefined_fragment()
 	{
 		$configs = new Config(self::$paths);
-		$this->assertNull($configs->synthesize('core', 'merge'));
+		$configs->synthesize(uniqid(), 'merge');
 	}
 
 	public function test_synthesize_with_array_merge()