Handle nullable screenshot directory

Signed-off-by: sschulz92 <[email protected]>

Author: sschulz92

getgauge/registry.py

@@ -228,7 +228,9 @@ def _get_step_value(step_text):
 
 
 def _take_screenshot():
-    temp_file = _uniqe_screenshot_file()
+    temp_file = _unique_screenshot_file()
+    if temp_file is None:
+        return
     try:
         call(['gauge_screenshot', temp_file])
         return os.path.basename(temp_file)
@@ -261,11 +263,12 @@ def capture():
     @staticmethod
     def capture_to_file():
         if not registry.is_screenshot_writer:
-            screenshot_file = _uniqe_screenshot_file()
-            content = registry.screenshot_provider()()
-            with open(screenshot_file, "wb") as file:
-                file.write(content)
-            return os.path.basename(screenshot_file)
+            screenshot_file = _unique_screenshot_file()
+            if screenshot_file:
+                content = registry.screenshot_provider()()
+                with open(screenshot_file, "wb") as file:
+                    file.write(content)
+                return os.path.basename(screenshot_file)
         screenshot_file = registry.screenshot_provider()()
         if not os.path.isabs(screenshot_file):
             screenshot_file = os.path.join(_screenshots_dir(), screenshot_file)
@@ -279,8 +282,12 @@ def clear():
         ScreenshotsStore.__screenshots = []
 
 
-def _uniqe_screenshot_file():
-    return os.path.join(_screenshots_dir(), "screenshot-{0}.png".format(uuid1().int))
+def _unique_screenshot_file():
+    screenshot_dir = _screenshots_dir()
+    if screenshot_dir:
+        return os.path.join(screenshot_dir, "screenshot-{0}.png".format(uuid1().int))
+    logger.warning("Could not create unique screenshot file as no directory is configured.")
+    return None
 
 
 def _screenshots_dir():