NEW make screenshot path configurable

#35

README.md

@@ -38,6 +38,11 @@ config file. This `base_url` is used when concatenating URLs by
 `SilverStripeContext->joinUrlParts()` method. `admin_url` and `login_url` should not
 be changed in general (unless they are not correct)
 
+Optional `screenshot_path` variable is used to store screenshot of a last know state
+of a failed step. It defaults to whatever is returned by PHP's `sys_get_temp_dir()`.
+Screenshot names within that directory consist of feature file filename and line
+number that failed.
+
     # behat.yml
     default:
       # ...
@@ -46,6 +51,7 @@ be changed in general (unless they are not correct)
           base_url: http://localhost
           admin_url: /admin/
           login_url: /Security/login
+          screenshot_path: features/screenshots/
 
 ### Configuring extensions
 

behat.yml

@@ -5,6 +5,7 @@ default:
       base_url: http://localhost
       admin_url: /admin/
       login_url: /Security/login
+      screenshot_path: features/screenshots/
   extensions:
     features/extensions/SilverStripeExtension/init.php:
 #    Behat\SilverStripeExtension\Extension:

features/bootstrap/SilverStripe/Test/Behaviour/BasicContext.php

@@ -156,7 +156,22 @@ public function takeScreenshotAfterFailedStep(StepEvent $event)
             $feature = $parent->getFeature();
             $step = $event->getStep();
 
-            $screenshot_path = realpath(sprintf('%s/%s_%d.png', sys_get_temp_dir(), basename($feature->getFile()), $step->getLine()));
+            if (isset($this->context['screenshot_path'])) {
+                $screenshot_path = realpath($this->context['screenshot_path']);
+            } else {
+                $screenshot_path = realpath(sys_get_temp_dir());
+            }
+
+            if (!is_dir($screenshot_path)) {
+                file_put_contents('php://stderr', sprintf('"%s" is not valid directory' . PHP_EOL, $this->context['screenshot_path']));
+                return;
+            }
+            if (!is_writable($screenshot_path)) {
+                file_put_contents('php://stderr', sprintf('"%s" directory is not writable' . PHP_EOL, $screenshot_path));
+                return;
+            }
+
+            $screenshot_path = sprintf('%s/%s_%d.png', $screenshot_path, basename($feature->getFile()), $step->getLine());
             $screenshot = $driver->wdSession->screenshot();
             file_put_contents($screenshot_path, base64_decode($screenshot));
             file_put_contents('php://stderr', sprintf('Saving screenshot into %s' . PHP_EOL, $screenshot_path));