implement response check (aio-libs#3892)

* implement response check, aio-libs#3864

* switch to raise_for_status coroutine

* fix linting

* revert name corrections

* fix types, add request tests

* change and docs

* allow non callable truey raise_for_status

(cherry picked from commit e5beaca)

CHANGES/3892.feature

@@ -0,0 +1 @@
+allow ``raise_for_status`` to be a coroutine

aiohttp/client.py

@@ -213,7 +213,7 @@ def __init__(
         version: HttpVersion = http.HttpVersion11,
         cookie_jar: Optional[AbstractCookieJar] = None,
         connector_owner: bool = True,
-        raise_for_status: bool = False,
+        raise_for_status: Union[bool, Callable[[ClientResponse], Awaitable[None]]] = False,  # noqa
         read_timeout: Union[float, object] = sentinel,
         conn_timeout: Optional[float] = None,
         timeout: Union[object, ClientTimeout] = sentinel,
@@ -380,7 +380,7 @@ async def _request(
         compress: Optional[str] = None,
         chunked: Optional[bool] = None,
         expect100: bool = False,
-        raise_for_status: Optional[bool] = None,
+        raise_for_status: Union[None, bool, Callable[[ClientResponse], Awaitable[None]]] = None,  # noqa
         read_until_eof: bool = True,
         proxy: Optional[StrOrURL] = None,
         proxy_auth: Optional[BasicAuth] = None,
@@ -645,7 +645,12 @@ async def _request(
             # check response status
             if raise_for_status is None:
                 raise_for_status = self._raise_for_status
-            if raise_for_status:
+
+            if raise_for_status is None:
+                pass
+            elif callable(raise_for_status):
+                await raise_for_status(resp)
+            elif raise_for_status:
                 resp.raise_for_status()
 
             # register connection

docs/client_reference.rst

@@ -135,6 +135,22 @@ The client session supports the context manager protocol for self closing.
       requests where you need to handle responses with status 400 or
       higher.
 
+      You can also provide a coroutine which takes the response as an
+      argument and can raise an exception based on custom logic, e.g.::
+
+          async def custom_check(response):
+              if response.status not in {201, 202}:
+                  raise RuntimeError('expected either 201 or 202')
+              text = await response.text()
+              if 'apple pie' not in text:
+                  raise RuntimeError('I wanted to see "apple pie" in response')
+
+          client_session = aiohttp.ClientSession(raise_for_status=custom_check)
+          ...
+
+      As with boolean values, you're free to set this on the session and/or
+      overwrite it on a per-request basis.
+
    :param timeout: a :class:`ClientTimeout` settings structure, 300 seconds (5min)
         total timeout by default.
 

tests/test_client_functional.py

@@ -2309,6 +2309,56 @@ async def handler(request):
             assert False, "never executed"  # pragma: no cover
 
 
+async def test_session_raise_for_status_coro(aiohttp_client) -> None:
+
+    async def handle(request):
+        return web.Response(text='ok')
+
+    app = web.Application()
+    app.router.add_route('GET', '/', handle)
+
+    raise_for_status_called = 0
+
+    async def custom_r4s(response):
+        nonlocal raise_for_status_called
+        raise_for_status_called += 1
+        assert response.status == 200
+        assert response.request_info.method == 'GET'
+
+    client = await aiohttp_client(app, raise_for_status=custom_r4s)
+    await client.get('/')
+    assert raise_for_status_called == 1
+    await client.get('/', raise_for_status=True)
+    assert raise_for_status_called == 1  # custom_r4s not called again
+    await client.get('/', raise_for_status=False)
+    assert raise_for_status_called == 1  # custom_r4s not called again
+
+
+async def test_request_raise_for_status_coro(aiohttp_client) -> None:
+
+    async def handle(request):
+        return web.Response(text='ok')
+
+    app = web.Application()
+    app.router.add_route('GET', '/', handle)
+
+    raise_for_status_called = 0
+
+    async def custom_r4s(response):
+        nonlocal raise_for_status_called
+        raise_for_status_called += 1
+        assert response.status == 200
+        assert response.request_info.method == 'GET'
+
+    client = await aiohttp_client(app)
+    await client.get('/', raise_for_status=custom_r4s)
+    assert raise_for_status_called == 1
+    await client.get('/', raise_for_status=True)
+    assert raise_for_status_called == 1  # custom_r4s not called again
+    await client.get('/', raise_for_status=False)
+    assert raise_for_status_called == 1  # custom_r4s not called again
+
+
 async def test_invalid_idna() -> None:
     session = aiohttp.ClientSession()
     try: