Add ArrayIO helper to capture output

src/Composer/IO/ArrayIO.php

@@ -0,0 +1,46 @@
+<?php
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\IO;
+
+use Symfony\Component\Console\Output\StreamOutput;
+use Symfony\Component\Console\Input\StringInput;
+use Symfony\Component\Console\Helper\HelperSet;
+
+/**
+ * The Input/Output helper.
+ *
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ */
+class ArrayIO extends ConsoleIO
+{
+    /**
+     * @param string $input
+     * @param int    $verbosity
+     */
+    public function __construct($input = '', $verbosity = null)
+    {
+        $input = new StringInput($input);
+        $input->setInteractive(false);
+
+        // TODO pass a custom output formatter for html tags
+        $output = new StreamOutput(fopen('php://memory', 'rw'), $verbosity === null ? StreamOutput::VERBOSITY_NORMAL : $verbosity, false);
+
+        parent::__construct($input, $output, new HelperSet(array()));
+    }
+
+    public function getOutput()
+    {
+        fseek($this->output->getStream(), 0);
+        return stream_get_contents($this->output->getStream());
+    }
+}