CS fixes & do not replace the exception since that removes the stack trace

src/Composer/Script/EventDispatcher.php

@@ -91,11 +91,9 @@ class EventDispatcher
             try {
                 $className::$methodName($event);
             } catch (\Exception $e) {
-                $message = "%s terminated with an exception.\n[%s] %s";
-                throw new \RuntimeException(sprintf($message,
-                                                    $callable,
-                                                    get_class($e),
-                                                    $e->getMessage()));
+                $message = "Script %s handling the %s event terminated with an exception";
+                $this->io->write('<error>'.sprintf($message, $callable, $event->getName()).'</error>');
+                throw $e;
             }
         }
     }

tests/Composer/Test/Script/EventDispatcherTest.php

@@ -1,4 +1,5 @@
 <?php
+
 /*
  * This file is part of Composer.
  *
@@ -15,36 +16,32 @@ use Composer\Test\TestCase;
 use Composer\Script\Event;
 use Composer\Script\EventDispatcher;
 
-/**
- * Event Dispatcher Test Case
- *
- * @group event-dispatcher
- * @ticket #693
- * @author Andrea Turso <turso@officinesoftware.co.uk>
- */
 class EventDispatcherTest extends TestCase
 {
     /**
-     * Test the doDispatch method properly catches any exception
-     * thrown from the listener invocation, i.e., <code>$className::$methodName($event)</code>,
-     * and replaces it with a \RuntimeException.
-     *
-     * @expectedException \RuntimeException
+     * @expectedException RuntimeException
      */
-    public function testListenerExceptionsAreSuppressed()
+    public function testListenerExceptionsAreCaught()
     {
+        $io = $this->getMock('Composer\IO\IOInterface');
         $dispatcher = $this->getDispatcherStubForListenersTest(array(
             "Composer\Test\Script\EventDispatcherTest::call"
-            ));
+        ), $io);
+
+        $io->expects($this->once())
+            ->method('write')
+            ->with('<error>Script Composer\Test\Script\EventDispatcherTest::call handling the post-install-cmd event terminated with an exception</error>');
+
         $dispatcher->dispatchCommandEvent("post-install-cmd");
     }
 
-    private function getDispatcherStubForListenersTest($listeners)
+    private function getDispatcherStubForListenersTest($listeners, $io)
     {
         $dispatcher = $this->getMockBuilder('Composer\Script\EventDispatcher')
             ->setConstructorArgs(array(
                 $this->getMock('Composer\Composer'),
-                               $this->getMock('Composer\IO\IOInterface')))
+                $io,
+            ))
             ->setMethods(array('getListeners'))
             ->getMock();
 
@@ -57,6 +54,6 @@ class EventDispatcherTest extends TestCase
 
     public static function call()
     {
-        throw new \Exception();
+        throw new \RuntimeException();
     }
 }