Preserve absent Domain attribute for ASGI response cookies

runtimes/v1/azure_functions_runtime_v1/bindings/datumdef.py

@@ -166,7 +166,7 @@ def parse_to_rpc_http_cookie_list(cookies: Optional[List[SimpleCookie]], protos)
                 protos.RpcHttpCookie(name=name,
                                      value=cookie_entity.value,
                                      domain=to_nullable_string(
-                                         cookie_entity['domain'],
+                                         cookie_entity['domain'] or None,
                                          'cookie.domain',
                                          protos),
                                      path=to_nullable_string(

runtimes/v1/tests/unittests/test_datumdef.py

@@ -67,6 +67,16 @@ def test_parse_cookie_attr_same_site_explicit_none(self):
     def test_parse_to_rpc_http_cookie_list_none(self):
         self.assertEqual(parse_to_rpc_http_cookie_list(None, protos), None)
 
+    def test_host_only_cookie_omits_domain(self):
+        cookie = SimpleCookie()
+        cookie.load('__Host-test=value; Path=/; Secure; HttpOnly; SameSite=Lax')
+
+        rpc_cookie = parse_to_rpc_http_cookie_list([cookie], protos)[0]
+
+        self.assertFalse(rpc_cookie.HasField('domain'))
+        self.assertEqual(rpc_cookie.path.value, '/')
+        self.assertTrue(rpc_cookie.secure.value)
+
     def test_parse_to_rpc_http_cookie_list_valid(self):
         headers = [
             'foo=bar; Path=/some/path; Secure; HttpOnly; Domain=123; '

runtimes/v2/azure_functions_runtime/bindings/datumdef.py

@@ -165,7 +165,7 @@ def parse_to_rpc_http_cookie_list(cookies: Optional[List[SimpleCookie]], protos)
                 protos.RpcHttpCookie(name=name,
                                      value=cookie_entity.value,
                                      domain=to_nullable_string(
-                                         cookie_entity['domain'],
+                                         cookie_entity['domain'] or None,
                                          'cookie.domain',
                                          protos),
                                      path=to_nullable_string(

runtimes/v2/tests/unittests/test_datumdef.py

@@ -67,6 +67,16 @@ def test_parse_cookie_attr_same_site_explicit_none(self):
     def test_parse_to_rpc_http_cookie_list_none(self):
         self.assertEqual(parse_to_rpc_http_cookie_list(None, protos), None)
 
+    def test_host_only_cookie_omits_domain(self):
+        cookie = SimpleCookie()
+        cookie.load('__Host-test=value; Path=/; Secure; HttpOnly; SameSite=Lax')
+
+        rpc_cookie = parse_to_rpc_http_cookie_list([cookie], protos)[0]
+
+        self.assertFalse(rpc_cookie.HasField('domain'))
+        self.assertEqual(rpc_cookie.path.value, '/')
+        self.assertTrue(rpc_cookie.secure.value)
+
     def test_parse_to_rpc_http_cookie_list_valid(self):
         headers = [
             'foo=bar; Path=/some/path; Secure; HttpOnly; Domain=123; '

workers/azure_functions_worker/bindings/datumdef.py

@@ -241,7 +241,7 @@ def parse_to_rpc_http_cookie_list(cookies: Optional[List[SimpleCookie]]):
                 protos.RpcHttpCookie(name=name,
                                      value=cookie_entity.value,
                                      domain=to_nullable_string(
-                                         cookie_entity['domain'],
+                                         cookie_entity['domain'] or None,
                                          'cookie.domain'),
                                      path=to_nullable_string(
                                          cookie_entity['path'], 'cookie.path'),

workers/tests/unittests/test_datumref.py

@@ -66,6 +66,16 @@ def test_parse_cookie_attr_same_site_explicit_none(self):
     def test_parse_to_rpc_http_cookie_list_none(self):
         self.assertEqual(parse_to_rpc_http_cookie_list(None), None)
 
+    def test_host_only_cookie_omits_domain(self):
+        cookie = SimpleCookie()
+        cookie.load('__Host-test=value; Path=/; Secure; HttpOnly; SameSite=Lax')
+
+        rpc_cookie = parse_to_rpc_http_cookie_list([cookie])[0]
+
+        self.assertFalse(rpc_cookie.HasField('domain'))
+        self.assertEqual(rpc_cookie.path.value, '/')
+        self.assertTrue(rpc_cookie.secure.value)
+
     def test_parse_to_rpc_http_cookie_list_valid(self):
         headers = [
             'foo=bar; Path=/some/path; Secure; HttpOnly; Domain=123; '

workers/tests/unittests/test_http_functions.py

@@ -376,7 +376,7 @@ def test_set_cookie_header_in_response_default_value(self):
                                  'set_cookie_resp_header_default_values')
         self.assertEqual(r.status_code, 200)
         self.assertEqual(r.headers.get('Set-Cookie'),
-                         'foo=bar; domain=; path=')
+                         'foo=bar; path=')
 
     def test_response_cookie_header_nullable_timestamp_err(self):
         r = self.webhost.request(