ma-1881 handling empty translations and testing

using lists for json serializability, if that's a word

common/lib/xmodule/xmodule/tests/test_video.py

@@ -920,3 +920,38 @@ class VideoDescriptorIndexingTestCase(unittest.TestCase):
             },
             "content_type": "Video"
         })
+
+    def test_video_with_multiple_transcripts_translation_retrieval(self):
+        """
+        Test translation retrieval of a video module with
+        multiple transcripts uploaded by a user.
+        """
+        xml_data_transcripts = '''
+            <video display_name="Test Video"
+                   youtube="1.0:p2Q6BrNhdh8,0.75:izygArpw-Qo,1.25:1EeWXzPdhSA,1.5:rABDYkeK0x8"
+                   show_captions="false"
+                   download_track="false"
+                   start_time="00:00:01"
+                   download_video="false"
+                   end_time="00:01:00">
+              <source src="http://www.example.com/source.mp4"/>
+              <track src="http://www.example.com/track"/>
+              <handout src="http://www.example.com/handout"/>
+              <transcript language="ge" src="subs_grmtran1.srt" />
+              <transcript language="hr" src="subs_croatian1.srt" />
+            </video>
+        '''
+
+        descriptor = instantiate_descriptor(data=xml_data_transcripts)
+        translations = descriptor.available_translations(descriptor.get_transcripts_info(), verify_assets=False)
+        self.assertEqual(translations, ['hr', 'ge'])
+
+    def test_video_with_no_transcripts_translation_retrieval(self):
+        """
+        Test translation retrieval of a video module with
+        no transcripts uploaded by a user- ie, that retrieval
+        does not throw an exception.
+        """
+        descriptor = instantiate_descriptor(data=None)
+        translations = descriptor.available_translations(descriptor.get_transcripts_info(), verify_assets=False)
+        self.assertEqual(translations, ['en'])

common/lib/xmodule/xmodule/video_module/transcripts_utils.py

@@ -569,14 +569,15 @@ class VideoTranscriptsMixin(object):
                 Defaults to False
         """
         translations = []
-        sub, other_lang = transcripts["sub"], transcripts["transcripts"]
+        sub, other_langs = transcripts["sub"], transcripts["transcripts"]
 
         # If we're not verifying the assets, we just trust our field values
         if not verify_assets:
-            translations = list(other_lang)
+            if other_langs:
+                translations = list(other_langs)
             if not translations or sub:
                 translations += ['en']
-            return set(translations)
+            return translations
 
         # If we've gotten this far, we're going to verify that the transcripts
         # being referenced are actually in the contentstore.
@@ -589,16 +590,16 @@ class VideoTranscriptsMixin(object):
                 except NotFoundError:
                     pass
                 else:
-                    translations = ['en']
+                    translations += ['en']
             else:
-                translations = ['en']
+                translations += ['en']
 
-        for lang in other_lang:
+        for lang in other_langs:
             try:
-                Transcript.asset(self.location, None, None, other_lang[lang])
+                Transcript.asset(self.location, None, None, other_langs[lang])
             except NotFoundError:
                 continue
-            translations.append(lang)
+            translations += [lang]
 
         return translations