Add tests for None response and _get_json_url

Fix code to deal with None

backdrop/core/repository.py

@@ -57,8 +57,10 @@ def __init__(self, stagecraft_url, stagecraft_token):
     def get_all(self):
         data_set_url = '{url}/data-sets'.format(url=self._stagecraft_url)
 
-        data_sets = _decode_json(_get_json_url(
-            data_set_url, self._stagecraft_token))
+        json_response = _get_json_url(
+            data_set_url, self._stagecraft_token) or '[]'
+        data_sets = _decode_json(json_response)
+
         return [_make_bucket_config(data_set) for data_set in data_sets]
 
     def retrieve(self, name):
@@ -85,9 +87,9 @@ def get_bucket_for_query(self, data_group, data_type):
                             url=self._stagecraft_url,
                             data_group_name=data_group,
                             data_type_name=data_type))
-
-        data_sets = _decode_json(_get_json_url(
-            data_set_url, self._stagecraft_token))
+        json_response = _get_json_url(
+            data_set_url, self._stagecraft_token) or '[]'
+        data_sets = _decode_json(json_response)
         if len(data_sets) > 0:
             return _make_bucket_config(data_sets[0])
         return None
@@ -113,12 +115,11 @@ def _get_json_url(url, token):
     try:
         response.raise_for_status()
     except requests.HTTPError as e:
-        logger.error('Got HTTP 404 for: {}'.format(url))
-        logger.exception(e)
         if e.response.status_code == 404:
-            return None
+            logger.error('Got HTTP 404 for: {}'.format(url))
+            logger.exception(e)
+            return None 
         raise e
-
     return response.content
 
 

tests/core/test_repository.py

@@ -3,13 +3,15 @@
 
 from backdrop.core.bucket import BucketConfig
 from backdrop.core.repository import (BucketConfigRepository,
-                                      UserConfigRepository)
+                                      UserConfigRepository,
+                                      _get_json_url)
 from hamcrest import assert_that, equal_to, is_, has_entries, match_equality
-from mock import Mock
+from mock import Mock, patch
 from nose.tools import assert_raises
 from backdrop.core.user import UserConfig
 from contextlib import contextmanager
 from os.path import dirname, join as pjoin
+import requests
 
 
 @contextmanager
@@ -18,12 +20,40 @@ def fixture(name):
     with open(filename, 'r') as f:
         yield f.read()
 
-#TODO: get json_url needs tests
-
-
 _GET_JSON_URL_FUNC = 'backdrop.core.repository._get_json_url'
 
 
+class TestGetJsonUrl(unittest.TestCase):
+
+    @patch('requests.get', spec=True)
+    def test_get_json_url_sends_correct_request(self, mock_get):
+        mock_response = Mock()
+        mock_response.content = '[]'
+        mock_get.return_value = mock_response 
+        response_content =  _get_json_url("my_url", "some_token")
+        mock_get.assert_called_once_with(
+             'my_url', 
+             headers={'content-type': 'application/json',
+                 'Authorization': 'Bearer some_token'})
+        assert_that(response_content, equal_to('[]'))
+
+
+    @patch('requests.get', spec=True)
+    def test_get_json_url_returns_none_on_404(self, mock_get):
+        exception = requests.HTTPError()
+        mock_error_response = Mock()
+        mock_error_response.status_code = 404
+        exception.response = mock_error_response 
+        def fake_raise_for_status():
+            raise exception
+
+        mock_response = Mock()
+        mock_response.raise_for_status = fake_raise_for_status
+        mock_get.return_value = mock_response
+        response_content =  _get_json_url("my_url", "some_token")
+        assert_that(response_content, is_(None))
+
+
 class TestBucketRepository(unittest.TestCase):
     def setUp(self):
         self.bucket_repo = BucketConfigRepository(
@@ -98,13 +128,28 @@ def test_get_bucket_for_query_correctly_decodes_stagecraft_response(self):
 
             assert_that(bucket, equal_to(expected_bucket))
 
-    def test_retrieving_non_existent_bucket_returns_none(self):
+    def test_retrieve_for_non_existent_bucket_returns_none(self):
         with mock.patch(_GET_JSON_URL_FUNC) as _get_json_url:
             _get_json_url.return_value = None
             bucket = self.bucket_repo.retrieve(name="non_existent")
 
         assert_that(bucket, is_(None))
 
+    def test_get_bucket_for_query_for_non_existent_bucket_returns_none(self):
+        with mock.patch(_GET_JSON_URL_FUNC) as _get_json_url:
+            _get_json_url.return_value = None
+            bucket = self.bucket_repo.get_bucket_for_query(
+                data_group="govuk", data_type="realtime")
+
+        assert_that(bucket, is_(None))
+
+    def test_get_all_for_non_existent_buckets_returns_empty_array(self):
+        with mock.patch(_GET_JSON_URL_FUNC) as _get_json_url:
+            _get_json_url.return_value = None
+            buckets = self.bucket_repo.get_all();
+
+        assert_that(buckets, is_([]))
+
     def test_retrieve_calls_correct_url_for_data_set_by_name(self):
         with fixture('stagecraft_get_single_data_set.json') as content:
             with mock.patch(_GET_JSON_URL_FUNC) as _get_json_url: