Handle request exceptions

src/newsreader/news/collection/exceptions.py

@@ -26,3 +26,7 @@ class StreamForbiddenException(StreamException):
 
 class StreamParseException(StreamException):
     message = "Stream could not be parsed"
+
+
+class StreamConnectionError(StreamException):
+    message = "A connection to the stream could not be made"

src/newsreader/news/collection/response_handler.py

@@ -1,9 +1,18 @@
 from typing import ContextManager
 
 from requests import Response
+from requests.exceptions import ConnectionError as RequestConnectionError
+from requests.exceptions import (
+    HTTPError,
+    RequestException,
+    SSLError,
+    TooManyRedirects,
+)
 
 from newsreader.news.collection.exceptions import (
+    StreamConnectionError,
     StreamDeniedException,
+    StreamException,
     StreamForbiddenException,
     StreamNotFoundException,
     StreamTimeOutException,
@@ -11,24 +20,32 @@ from newsreader.news.collection.exceptions import (
 
 
 class ResponseHandler:
-    message_mapping = {
+    status_code_mapping = {
         404: StreamNotFoundException,
         401: StreamDeniedException,
         403: StreamForbiddenException,
         408: StreamTimeOutException,
     }
 
-    def __init__(self, response: Response) -> None:
+    exception_mapping = {RequestConnectionError: StreamConnectionError}
-        self.response = response
 
     def __enter__(self) -> ContextManager:
         return self
 
-    def handle_response(self) -> None:
+    def handle_response(self, response) -> None:
-        status_code = self.response.status_code
+        status_code = response.status_code
 
-        if status_code in self.message_mapping:
+        if status_code in self.status_code_mapping:
-            raise self.message_mapping[status_code]
+            raise self.status_code_mapping[status_code]
+
+    def handle_exception(self, exception):
+        try:
+            stream_exception = self.exception_mapping[type(exception)]
+        except KeyError:
+            stream_exception = StreamException
+
+        message = getattr(exception, "message", str(exception))
+        raise stream_exception(message=message) from exception
 
     def __exit__(self, *args, **kwargs) -> None:
-        self.response = None
+        pass

src/newsreader/news/collection/tests/utils/tests.py

@@ -1,9 +1,19 @@
 from unittest.mock import MagicMock, patch
 
+from requests.exceptions import ConnectionError as RequestConnectionError
+from requests.exceptions import (
+    HTTPError,
+    RequestException,
+    SSLError,
+    TooManyRedirects,
+)
+
 from django.test import TestCase
 
 from newsreader.news.collection.exceptions import (
+    StreamConnectionError,
     StreamDeniedException,
+    StreamException,
     StreamForbiddenException,
     StreamNotFoundException,
     StreamTimeOutException,
@@ -55,3 +65,43 @@ class FetchTestCase(TestCase):
 
         with self.assertRaises(StreamTimeOutException):
             fetch(url)
+
+    def test_raises_stream_error_on_ssl_error(self):
+        self.mocked_get.side_effect = SSLError
+
+        url = "https://www.bbc.co.uk/news"
+
+        with self.assertRaises(StreamException):
+            fetch(url)
+
+    def test_raises_stream_error_on_connection_error(self):
+        self.mocked_get.side_effect = RequestConnectionError
+
+        url = "https://www.bbc.co.uk/news"
+
+        with self.assertRaises(StreamConnectionError):
+            fetch(url)
+
+    def test_raises_stream_error_on_http_error(self):
+        self.mocked_get.side_effect = HTTPError
+
+        url = "https://www.bbc.co.uk/news"
+
+        with self.assertRaises(StreamException):
+            fetch(url)
+
+    def test_raises_stream_error_on_request_exception(self):
+        self.mocked_get.side_effect = RequestException
+
+        url = "https://www.bbc.co.uk/news"
+
+        with self.assertRaises(StreamException):
+            fetch(url)
+
+    def test_raises_stream_error_on_too_many_redirects(self):
+        self.mocked_get.side_effect = TooManyRedirects
+
+        url = "https://www.bbc.co.uk/news"
+
+        with self.assertRaises(StreamException):
+            fetch(url)

src/newsreader/news/collection/utils.py

@@ -1,9 +1,10 @@
 from datetime import datetime, tzinfo
 from time import mktime, struct_time
-from typing import Optional, Tuple
+from typing import Tuple
 
 import requests
 
+from requests.exceptions import RequestException
 from requests.models import Response
 
 from django.utils import timezone
@@ -20,10 +21,12 @@ def build_publication_date(dt: struct_time, tz: tzinfo) -> Tuple:
     return True, published_parsed
 
 
-def fetch(url: str) -> Optional[Response]:
+def fetch(url: str) -> Response:
-    response = requests.get(url)
+    with ResponseHandler() as response_handler:
-
+        try:
-    with ResponseHandler(response) as response_handler:
+            response = requests.get(url)
-        response_handler.handle_response()
+            response_handler.handle_response(response)
+        except RequestException as exception:
+            response_handler.handle_exception(exception)
 
     return response