From 41a17d0566c6e6c5049e35f32e70d0ff1cad9ad5 Mon Sep 17 00:00:00 2001
From: "Dustin J. Mitchell" <dustin@v.igoro.us>
Date: Fri, 3 Jun 2016 14:25:21 -0500
Subject: [PATCH] Add client_resp.raise_for_status() (#908)

This method raises an exception for statuses that represent an error.
Closes #868.
---
 aiohttp/client_reqrep.py      |  6 ++++++
 docs/client_reference.rst     |  5 +++++
 tests/test_client_response.py | 13 +++++++++++++
 3 files changed, 24 insertions(+)

diff --git a/aiohttp/client_reqrep.py b/aiohttp/client_reqrep.py
index 656e31549c3..f2cc7c0fb5b 100644
--- a/aiohttp/client_reqrep.py
+++ b/aiohttp/client_reqrep.py
@@ -694,6 +694,12 @@ def release(self):
                 self._connection = None
             self._cleanup_writer()
 
+    def raise_for_status(self):
+        if 400 <= self.status:
+            raise aiohttp.HttpProcessingError(
+                code=self.status,
+                message=self.reason)
+
     def _cleanup_writer(self):
         if self._writer is not None and not self._writer.done():
             self._writer.cancel()
diff --git a/docs/client_reference.rst b/docs/client_reference.rst
index 5262ffe2507..c303a994e14 100644
--- a/docs/client_reference.rst
+++ b/docs/client_reference.rst
@@ -1149,6 +1149,11 @@ Response object
       return it into free connection pool for re-usage by next upcoming
       request.
 
+   .. method:: raise_for_status()
+
+      Raise an HttpProcessingError if the response status is 400 or higher.
+      Do nothing for success responses (less than 400).
+
    .. comethod:: text(encoding=None)
 
       Read response's body and return decoded :class:`str` using
diff --git a/tests/test_client_response.py b/tests/test_client_response.py
index 7b578f50169..99458e8b6a5 100644
--- a/tests/test_client_response.py
+++ b/tests/test_client_response.py
@@ -274,3 +274,16 @@ def test_close_deprecated(self):
         with self.assertWarns(DeprecationWarning):
             self.response.close(force=False)
         self.assertIsNone(self.response._connection)
+
+    def test_raise_for_status_2xx(self):
+        self.response.status = 200
+        self.response.reason = 'OK'
+        self.response.raise_for_status()  # should not raise
+
+    def test_raise_for_status_4xx(self):
+        self.response.status = 409
+        self.response.reason = 'CONFLICT'
+        with self.assertRaises(aiohttp.HttpProcessingError) as cm:
+            self.response.raise_for_status()
+        self.assertEqual(str(cm.exception.code), '409')
+        self.assertEqual(str(cm.exception.message), "CONFLICT")