add a triggered errors assertion helper

Author: xabbuh

ErrorAssert.php

@@ -0,0 +1,66 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Bridge\PhpUnit;
+
+/**
+ * Test that your code triggers expected error messages.
+ *
+ * @author Christian Flothmann <[email protected]>
+ */
+final class ErrorAssert
+{
+    /**
+     * @param string[] $expectedMessages Expected deprecation messages
+     * @param callable $testCode         A callable that is expected to trigger the expected deprecation messages when being executed
+     */
+    public static function assertDeprecationsAreTriggered($expectedMessages, $testCode)
+    {
+        if (!is_callable($testCode)) {
+            throw new \InvalidArgumentException(sprintf('The code to be tested must be a valid callable ("%s" given).', gettype($testCode)));
+        }
+
+        self::assertErrorsAreTriggered(E_USER_DEPRECATED, $expectedMessages, $testCode);
+    }
+
+    /**
+     * @param int      $expectedType     Expected triggered error type (pass one of PHP's E_* constants)
+     * @param string[] $expectedMessages Expected error messages
+     * @param callable $testCode         A callable that is expected to trigger the expected messages when being executed
+     */
+    public static function assertErrorsAreTriggered($expectedType, $expectedMessages, $testCode)
+    {
+        if (!is_callable($testCode)) {
+            throw new \InvalidArgumentException(sprintf('The code to be tested must be a valid callable ("%s" given).', gettype($testCode)));
+        }
+
+        $triggeredMessages = array();
+
+        try {
+            $prevHandler = set_error_handler(function ($type, $message, $file, $line, $context) use ($expectedType, &$triggeredMessages, &$prevHandler) {
+                if ($expectedType !== $type) {
+                    return null !== $prevHandler && call_user_func($prevHandler, $type, $message, $file, $line, $context);
+                }
+                $triggeredMessages[] = $message;
+            });
+
+            $testCode();
+        } finally {
+            restore_error_handler();
+        }
+
+        \PHPUnit_Framework_Assert::assertCount(count($expectedMessages), $triggeredMessages);
+
+        for ($i = 0; $i < count($triggeredMessages); ++$i) {
+            \PHPUnit_Framework_Assert::assertContains($expectedMessages[$i], $triggeredMessages[$i]);
+        }
+    }
+}