fix aiohttp kyes and values to be mutable

sdk/core/azure-core/azure/core/rest/_aiohttp.py

@@ -38,7 +38,6 @@ class _ItemsView(collections.abc.ItemsView):
     def __init__(self, ref):
         super().__init__(ref)
         self._ref = ref
-        self._items = []
 
     def __iter__(self):
         for key, groups in groupby(self._ref.__iter__(), lambda x: x[0]):
@@ -55,6 +54,41 @@ def __contains__(self, item):
     def __repr__(self):
         return f"dict_items({list(self.__iter__())})"
 
+class _KeysView(collections.abc.KeysView):
+    def __init__(self, items):
+        super().__init__(items)
+        self._items = items
+
+    def __iter__(self):
+        for key, _ in self._items:
+            yield key
+
+    def __contains__(self, key):
+        for k in self.__iter__():
+            if key.lower() == k.lower():
+                return True
+        return False
+    def __repr__(self):
+        return f"dict_keys({list(self.__iter__())})"
+
+class _ValuesView(collections.abc.ValuesView):
+    def __init__(self, items):
+        super().__init__(items)
+        self._items = items
+
+    def __iter__(self):
+        for _, value in self._items:
+            yield value
+
+    def __contains__(self, value):
+        for v in self.__iter__():
+            if value == v:
+                return True
+        return False
+
+    def __repr__(self):
+        return f"dict_values({list(self.__iter__())})"
+
 
 class _CIMultiDict(CIMultiDict):
     """Dictionary with the support for duplicate case-insensitive keys."""
@@ -64,15 +98,15 @@ def __iter__(self):
 
     def keys(self):
         """Return a new view of the dictionary's keys."""
-        return dict(self.items()).keys()
+        return _KeysView(self.items())
 
     def items(self):
         """Return a new view of the dictionary's items."""
         return _ItemsView(super().items())
 
     def values(self):
         """Return a new view of the dictionary's values."""
-        return dict(self.items()).values()
+        return _ValuesView(self.items())
 
     def __getitem__(self, key: str) -> str:
         return ", ".join(self.getall(key, []))

sdk/core/azure-core/azure/core/rest/_requests_basic.py

@@ -23,27 +23,31 @@
 # IN THE SOFTWARE.
 #
 # --------------------------------------------------------------------------
+import collections
 from typing import TYPE_CHECKING, cast
+from requests.structures import CaseInsensitiveDict
 
 from ..exceptions import ResponseNotReadError, StreamConsumedError, StreamClosedError
 from ._rest import _HttpResponseBase, HttpResponse
 from ..pipeline.transport._requests_basic import StreamDownloadGenerator
-from collections import ItemsView
-from requests.structures import CaseInsensitiveDict
 
-class _ItemsView(ItemsView):
+class _ItemsView(collections.ItemsView):
     def __contains__(self, item):
         if not (isinstance(item, (list, tuple)) and len(item) == 2):
-            return False
+            return False  # requests raises here, we just return False
         for k, v in self.__iter__():
             if item[0].lower() == k.lower() and item[1] == v:
                 return True
         return False
 
     def __repr__(self):
-        return 'ItemsView({0._mapping!r})'.format(self)
+        return 'ItemsView({})'.format(dict(self.__iter__()))
 
 class _CaseInsensitiveDict(CaseInsensitiveDict):
+    """Overriding default requests dict so we can unify
+    to not raise if users pass in incorrect items to contains.
+    Instead, we return False
+    """
 
     def items(self):
         """Return a new view of the dictionary's items."""

sdk/core/azure-core/azure/core/rest/_rest.py

@@ -305,7 +305,9 @@ class HttpResponse(_HttpResponseBase):  # pylint: disable=too-many-instance-attr
     :keyword request: The request that resulted in this response.
     :paramtype request: ~azure.core.rest.HttpRequest
     :ivar int status_code: The status code of this response
-    :ivar mapping headers: The response headers
+    :ivar mapping headers: The case-insensitive response headers.
+     While looking up headers is case-insensitive, when looking up
+     keys in `header.keys()`, we recommend using lowercase.
     :ivar str reason: The reason phrase for this response
     :ivar bytes content: The response content in bytes.
     :ivar str url: The URL that resulted in this response

sdk/core/azure-core/azure/core/rest/_rest_py3.py

@@ -319,7 +319,9 @@ class HttpResponse(_HttpResponseBase):
     :keyword request: The request that resulted in this response.
     :paramtype request: ~azure.core.rest.HttpRequest
     :ivar int status_code: The status code of this response
-    :ivar mapping headers: The response headers
+    :ivar mapping headers: The case-insensitive response headers.
+     While looking up headers is case-insensitive, when looking up
+     keys in `header.keys()`, we recommend using lowercase.
     :ivar str reason: The reason phrase for this response
     :ivar bytes content: The response content in bytes.
     :ivar str url: The URL that resulted in this response

sdk/core/azure-core/tests/testserver_tests/async_tests/test_rest_headers_async.py

@@ -57,9 +57,9 @@ async def test_headers_response_keys(get_response_headers):
     assert list(h.keys()) == list(ref_dict.keys())
     assert repr(h.keys()) == repr(ref_dict.keys())
     assert "a" in h.keys()
-    assert "A" not in h.keys()
+    assert "A" in h.keys()
     assert "b" in h.keys()
-    assert "B" not in h.keys()
+    assert "B" in h.keys()
     assert set(h.keys()) == set(ref_dict.keys())
 
     # test mutability