output_type should not be optional in new_output

and fix bug that this would have revealed

IPython/html/nbconvert/tests/test_nbconvert_handlers.py

@@ -58,7 +58,7 class APITest(NotebookTestBase):
         nb.worksheets = [ws]
         ws.cells.append(new_heading_cell(u'Created by test ³'))
         cc1 = new_code_cell(input=u'print(2*6)')
-        cc1.outputs.append(new_output(output_text=u'12'))
+        cc1.outputs.append(new_output(output_text=u'12', output_type='stream'))
         cc1.outputs.append(new_output(output_png=png_green_pixel, output_type='pyout'))
         ws.cells.append(cc1)
         

IPython/nbformat/v3/nbbase.py

@@ -4,22 +4,10 The Python representation of a notebook is a nested structure of
 dictionary subclasses that support attribute access
 (IPython.utils.ipstruct.Struct). The functions in this module are merely
 helpers to build the structs in the right form.
-
-Authors:
-
-* Brian Granger
 """
 
-#-----------------------------------------------------------------------------
-#  Copyright (C) 2008-2011  The IPython Development Team
-#
-#  Distributed under the terms of the BSD License.  The full license is in
-#  the file COPYING, distributed as part of this software.
-#-----------------------------------------------------------------------------
-
-#-----------------------------------------------------------------------------
-# Imports
-#-----------------------------------------------------------------------------
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
 
 import pprint
 import uuid
@@ -51,15 +39,14 def from_dict(d):
         return d
 
 
-def new_output(output_type=None, output_text=None, output_png=None,
+def new_output(output_type, output_text=None, output_png=None,
     output_html=None, output_svg=None, output_latex=None, output_json=None,
     output_javascript=None, output_jpeg=None, prompt_number=None,
     ename=None, evalue=None, traceback=None, stream=None, metadata=None):
     """Create a new output, to go in the ``cell.outputs`` list of a code cell.
     """
     output = NotebookNode()
-    if output_type is not None:
-        output.output_type = unicode_type(output_type)
+    output.output_type = unicode_type(output_type)
 
     if metadata is None:
         metadata = {}

IPython/nbformat/v3/tests/test_nbbase.py

@@ -143,15 +143,15 class TestMetadata(TestCase):
 
 class TestOutputs(TestCase):
     def test_binary_png(self):
-        out = new_output(output_png=b'\x89PNG\r\n\x1a\n')
+        out = new_output(output_png=b'\x89PNG\r\n\x1a\n', output_type='display_data')
 
     def test_b64b6tes_png(self):
-        out = new_output(output_png=b'iVBORw0KG')
+        out = new_output(output_png=b'iVBORw0KG', output_type='display_data')
     
     def test_binary_jpeg(self):
-        out = new_output(output_jpeg=b'\xff\xd8')
+        out = new_output(output_jpeg=b'\xff\xd8', output_type='display_data')
 
     def test_b64b6tes_jpeg(self):
-        out = new_output(output_jpeg=b'/9')
+        out = new_output(output_jpeg=b'/9', output_type='display_data')