handle '_DuplicateWriter' object has no attribute 'buffer'

python/subunit/__init__.py

@@ -158,6 +158,26 @@ def test_script_two(self):
 PROGRESS_POP = 3
 
 
+def is_stdout_DuplicateWriter(sys_stdout):
+    """
+    Returns a boolean, type checking sys.stdout to see if it was overriden by the unittest-xml-reporting
+    module without importing, matching type xmlrunner.result._DuplicateWriter.
+
+    @param sys_stdout: The current sys.stdout object.
+
+    @return: (bool) True if of type xmlrunner.result._DuplicateWriter, else False.
+    """
+    xmlrunner_module = 'xmlrunner'
+    if xmlrunner_module in sys.modules:
+        if hasattr(sys.modules[xmlrunner_module], 'result'):
+            if hasattr(sys.modules[xmlrunner_module].result, '_DuplicateWriter'):
+                return isinstance(sys_stdout, sys.modules[xmlrunner_module].result._DuplicateWriter)
+
+        return False
+    else:
+        return False
+
+
 def test_suite():
     import subunit.tests
     return subunit.tests.test_suite()
@@ -506,7 +526,13 @@ def __init__(self, client, stream=None, forward_stream=None):
         """
         self.client = ExtendedToOriginalDecorator(client)
         if stream is None:
-            stream = sys.stdout.buffer
+            if hasattr(sys.stdout, 'buffer'):
+                stream = sys.stdout.buffer
+            else:
+                # check if sys.stdout was overridden by unittest-xml-reporting module with no buffer
+                if is_stdout_DuplicateWriter(sys.stdout):
+                    stream = sys.stdout
+
         self._stream = stream
         self._forward_stream = forward_stream or DiscardStream()
         # state objects we can switch too