test that PNG / JPEG output data are unicode

IPython/nbformat/v3/tests/nbexamples.py

@@ -9,9 +9,9 b' from ..nbbase import ('
     new_metadata, new_author, new_heading_cell, nbformat, nbformat_minor
 )
 
-# some random base64-encoded *bytes*
-png = encodestring(os.urandom(5))
-jpeg = encodestring(os.urandom(6))
+# some random base64-encoded *text*
+png = encodestring(os.urandom(5)).decode('ascii')
+jpeg = encodestring(os.urandom(6)).decode('ascii')
 
 ws = new_worksheet(name='worksheet1')
 

IPython/nbformat/v3/tests/test_json.py

@@ -1,4 +1,5 b''
 import pprint
+from base64 import decodestring
 from unittest import TestCase
 
 from ..nbjson import reads, writes
@@ -29,5 +30,42 b' class TestJSON(formattest.NBFormatTest, TestCase):'
         s = writes(nb0, split_lines=True)
         self.assertEqual(nbjson.reads(s),nb0)
 
+    def test_read_png(self):
+        """PNG output data is b64 unicode"""
+        s = writes(nb0)
+        nb1 = nbjson.reads(s)
+        found_png = False
+        for cell in nb1.worksheets[0].cells:
+            if not 'outputs' in cell:
+                continue
+            for output in cell.outputs:
+                if 'png' in output:
+                    found_png = True
+                    pngdata = output['png']
+                    self.assertEqual(type(pngdata), unicode)
+                    # test that it is valid b64 data
+                    b64bytes = pngdata.encode('ascii')
+                    raw_bytes = decodestring(b64bytes)
+        assert found_png, "never found png output"
+
+    def test_read_jpeg(self):
+        """JPEG output data is b64 unicode"""
+        s = writes(nb0)
+        nb1 = nbjson.reads(s)
+        found_jpeg = False
+        for cell in nb1.worksheets[0].cells:
+            if not 'outputs' in cell:
+                continue
+            for output in cell.outputs:
+                if 'jpeg' in output:
+                    found_jpeg = True
+                    jpegdata = output['jpeg']
+                    self.assertEqual(type(jpegdata), unicode)
+                    # test that it is valid b64 data
+                    b64bytes = jpegdata.encode('ascii')
+                    raw_bytes = decodestring(b64bytes)
+        assert found_jpeg, "never found jpeg output"
+
+