From be8b89500c47a6155239977da71fa56c3d6ec17b Mon Sep 17 00:00:00 2001
From: Mark Johnson <mark.johnson@open.ac.uk>
Date: Thu, 12 May 2016 09:49:24 +0100
Subject: [PATCH] MDL-54180 Behat: Handle exceptions from driver when saving
 screenshot

---
 lib/tests/behat/behat_hooks.php | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/lib/tests/behat/behat_hooks.php b/lib/tests/behat/behat_hooks.php
index c2a9862d141..0b954133e11 100644
--- a/lib/tests/behat/behat_hooks.php
+++ b/lib/tests/behat/behat_hooks.php
@@ -429,8 +429,19 @@ class behat_hooks extends behat_base {
             return false;
         }
 
-        list ($dir, $filename) = $this->get_faildump_filename($scope, 'png');
-        $this->saveScreenshot($filename, $dir);
+        // Some drivers (e.g. chromedriver) may throw an exception while trying to take a screenshot.  If this isn't handled,
+        // the behat run dies.  We don't want to lose the information about the failure that triggered the screenshot,
+        // so let's log the exception message to a file (to explain why there's no screenshot) and allow the run to continue,
+        // handling the failure as normal.
+        try {
+            list ($dir, $filename) = $this->get_faildump_filename($scope, 'png');
+            $this->saveScreenshot($filename, $dir);
+        } catch (Exception $e) {
+            // Catching all exceptions as we don't know what the driver might throw.
+            list ($dir, $filename) = $this->get_faildump_filename($scope, 'txt');
+            $message = "Could not save screenshot due to an error\n" . $e->getMessage();
+            file_put_contents($dir . DIRECTORY_SEPARATOR . $filename, $message);
+        }
     }
 
     /**
@@ -442,9 +453,14 @@ class behat_hooks extends behat_base {
     protected function take_contentdump(AfterStepScope $scope) {
         list ($dir, $filename) = $this->get_faildump_filename($scope, 'html');
 
-        $fh = fopen($dir . DIRECTORY_SEPARATOR . $filename, 'w');
-        fwrite($fh, $this->getSession()->getPage()->getContent());
-        fclose($fh);
+        try {
+            // Driver may throw an exception during getContent(), so do it first to avoid getting an empty file.
+            $content = $this->getSession()->getPage()->getContent();
+        } catch (Exception $e) {
+            // Catching all exceptions as we don't know what the driver might throw.
+            $content = "Could not save contentdump due to an error\n" . $e->getMessage();
+        }
+        file_put_contents($dir . DIRECTORY_SEPARATOR . $filename, $content);
     }
 
     /**