Setup Content-Type to application/octet-stream by default

aiohttp/web_reqrep.py

@@ -774,7 +774,7 @@ def __init__(self, *, body=None, status=200,
         self.set_tcp_cork(True)
 
         if body is not None and text is not None:
-            raise ValueError("body and text are not allowed together.")
+            raise ValueError('body and text are not allowed together')
 
         if text is not None:
             if hdrs.CONTENT_TYPE not in self.headers:
@@ -794,25 +794,23 @@ def __init__(self, *, body=None, status=200,
                 self._content_dict = {'charset': charset}
                 self.body = text.encode(charset)
             else:
-                self.text = text
                 if content_type or charset:
-                    raise ValueError("Passing both Content-Type header and "
-                                     "content_type or charset params "
-                                     "is forbidden")
+                    raise ValueError('passing both Content-Type header and '
+                                     'content_type or charset params '
+                                     'is forbidden')
+                self.text = text
         else:
             if hdrs.CONTENT_TYPE in self.headers:
                 if content_type or charset:
-                    raise ValueError("Passing both Content-Type header and "
-                                     "content_type or charset params "
-                                     "is forbidden")
-            if content_type:
-                self.content_type = content_type
+                    raise ValueError('passing both Content-Type header and '
+                                     'content_type or charset params '
+                                     'is forbidden')
+            if content_type is None:
+                content_type = 'application/octet-stream'
+            self.content_type = content_type
             if charset:
                 self.charset = charset
-            if body is not None:
-                self.body = body
-            else:
-                self.body = None
+            self.body = body
 
     @property
     def body(self):

docs/web_reference.rst

@@ -680,14 +680,14 @@ Response
 
    .. attribute:: text
 
-      Read-write attribute for storing response's content, represented as str,
-      :class:`str`.
+      Read-write attribute for storing response's content, represented as
+      string, :class:`str`.
 
-      Setting :attr:`str` also recalculates
+      Setting :attr:`text` also recalculates
       :attr:`~StreamResponse.content_length` value and
       :attr:`~StreamResponse.body` value
 
-      Resetting :attr:`body` (assigning ``None``) sets
+      Resetting :attr:`text` (assigning ``None``) sets
       :attr:`~StreamResponse.content_length` to ``None`` too, dropping
       *Content-Length* HTTP header.
 

tests/test_web_response.py

@@ -887,6 +887,16 @@ def test_set_text_with_charset():
     assert "koi8-r" == resp.charset
 
 
+def test_content_type_with_set_text():
+    resp = Response(text='text')
+    assert resp.content_type == 'text/plain'
+
+
+def test_content_type_with_set_body():
+    resp = Response(body=b'body')
+    assert resp.content_type == 'application/octet-stream'
+
+
 def test_started_when_not_started():
     resp = StreamResponse()
     assert not resp.prepared