Remove unnecessary `json.dumps` from tests (#13303)

13 files changed, 143 insertions, 200 deletions

diff --git a/changelog.d/13303.misc b/changelog.d/13303.misc
new file mode 100644
index 0000000000..03f64ab171
--- /dev/null
+++ b/changelog.d/13303.misc
@@ -0,0 +1 @@
+Remove unnecessary `json.dumps` from tests.
\ No newline at end of file
diff --git a/tests/rest/client/test_account.py b/tests/rest/client/test_account.py
index 6d6a26b8f4..7ae926dc9c 100644
--- a/tests/rest/client/test_account.py
+++ b/tests/rest/client/test_account.py
@@ -11,7 +11,6 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-import json
 import os
 import re
 from email.parser import Parser
@@ -96,9 +95,7 @@ class PasswordResetTestCase(unittest.HomeserverTestCase):
         """
         body = {"type": "m.login.password", "user": username, "password": password}
 
-        channel = self.make_request(
-            "POST", "/_matrix/client/r0/login", json.dumps(body).encode("utf8")
-        )
+        channel = self.make_request("POST", "/_matrix/client/r0/login", body)
         self.assertEqual(channel.code, HTTPStatus.FORBIDDEN, channel.result)
 
     def test_basic_password_reset(self) -> None:
@@ -480,16 +477,14 @@ class DeactivateTestCase(unittest.HomeserverTestCase):
         self.assertEqual(memberships[0].room_id, room_id, memberships)
 
     def deactivate(self, user_id: str, tok: str) -> None:
-        request_data = json.dumps(
-            {
-                "auth": {
-                    "type": "m.login.password",
-                    "user": user_id,
-                    "password": "test",
-                },
-                "erase": False,
-            }
-        )
+        request_data = {
+            "auth": {
+                "type": "m.login.password",
+                "user": user_id,
+                "password": "test",
+            },
+            "erase": False,
+        }
         channel = self.make_request(
             "POST", "account/deactivate", request_data, access_token=tok
         )
diff --git a/tests/rest/client/test_directory.py b/tests/rest/client/test_directory.py
index 16e7ef41bc..7a88aa2cda 100644
--- a/tests/rest/client/test_directory.py
+++ b/tests/rest/client/test_directory.py
@@ -11,7 +11,6 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-import json
 from http import HTTPStatus
 
 from twisted.test.proto_helpers import MemoryReactor
@@ -97,8 +96,7 @@ class DirectoryTestCase(unittest.HomeserverTestCase):
 
         # We use deliberately a localpart under the length threshold so
         # that we can make sure that the check is done on the whole alias.
-        data = {"room_alias_name": random_string(256 - len(self.hs.hostname))}
-        request_data = json.dumps(data)
+        request_data = {"room_alias_name": random_string(256 - len(self.hs.hostname))}
         channel = self.make_request(
             "POST", url, request_data, access_token=self.user_tok
         )
@@ -110,8 +108,7 @@ class DirectoryTestCase(unittest.HomeserverTestCase):
         # Check with an alias of allowed length. There should already be
         # a test that ensures it works in test_register.py, but let's be
         # as cautious as possible here.
-        data = {"room_alias_name": random_string(5)}
-        request_data = json.dumps(data)
+        request_data = {"room_alias_name": random_string(5)}
         channel = self.make_request(
             "POST", url, request_data, access_token=self.user_tok
         )
@@ -144,8 +141,7 @@ class DirectoryTestCase(unittest.HomeserverTestCase):
 
         # Add an alias for the room, as the appservice
         alias = RoomAlias(f"asns-{random_string(5)}", self.hs.hostname).to_string()
-        data = {"room_id": self.room_id}
-        request_data = json.dumps(data)
+        request_data = {"room_id": self.room_id}
 
         channel = self.make_request(
             "PUT",
@@ -193,8 +189,7 @@ class DirectoryTestCase(unittest.HomeserverTestCase):
             self.hs.hostname,
         )
 
-        data = {"aliases": [self.random_alias(alias_length)]}
-        request_data = json.dumps(data)
+        request_data = {"aliases": [self.random_alias(alias_length)]}
 
         channel = self.make_request(
             "PUT", url, request_data, access_token=self.user_tok
@@ -206,8 +201,7 @@ class DirectoryTestCase(unittest.HomeserverTestCase):
     ) -> str:
         alias = self.random_alias(alias_length)
         url = "/_matrix/client/r0/directory/room/%s" % alias
-        data = {"room_id": self.room_id}
-        request_data = json.dumps(data)
+        request_data = {"room_id": self.room_id}
 
         channel = self.make_request(
             "PUT", url, request_data, access_token=self.user_tok
diff --git a/tests/rest/client/test_identity.py b/tests/rest/client/test_identity.py
index 299b9d21e2..dc17c9d113 100644
--- a/tests/rest/client/test_identity.py
+++ b/tests/rest/client/test_identity.py
@@ -12,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import json
 from http import HTTPStatus
 
 from twisted.test.proto_helpers import MemoryReactor
@@ -51,12 +50,11 @@ class IdentityTestCase(unittest.HomeserverTestCase):
         self.assertEqual(channel.code, HTTPStatus.OK, channel.result)
         room_id = channel.json_body["room_id"]
 
-        params = {
+        request_data = {
             "id_server": "testis",
             "medium": "email",
             "address": "test@example.com",
         }
-        request_data = json.dumps(params)
         request_url = ("/rooms/%s/invite" % (room_id)).encode("ascii")
         channel = self.make_request(
             b"POST", request_url, request_data, access_token=tok
diff --git a/tests/rest/client/test_login.py b/tests/rest/client/test_login.py
index e7f5517e34..a2958f6959 100644
--- a/tests/rest/client/test_login.py
+++ b/tests/rest/client/test_login.py
@@ -11,7 +11,6 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-import json
 import time
 import urllib.parse
 from http import HTTPStatus
@@ -400,7 +399,7 @@ class LoginRestServletTestCase(unittest.HomeserverTestCase):
         channel = self.make_request(
             "POST",
             "/_matrix/client/v3/login",
-            json.dumps(body).encode("utf8"),
+            body,
             custom_headers=None,
         )
 
diff --git a/tests/rest/client/test_password_policy.py b/tests/rest/client/test_password_policy.py
index 3a74d2e96c..e19d21d6ee 100644
--- a/tests/rest/client/test_password_policy.py
+++ b/tests/rest/client/test_password_policy.py
@@ -12,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import json
 from http import HTTPStatus
 
 from twisted.test.proto_helpers import MemoryReactor
@@ -89,7 +88,7 @@ class PasswordPolicyTestCase(unittest.HomeserverTestCase):
         )
 
     def test_password_too_short(self) -> None:
-        request_data = json.dumps({"username": "kermit", "password": "shorty"})
+        request_data = {"username": "kermit", "password": "shorty"}
         channel = self.make_request("POST", self.register_url, request_data)
 
         self.assertEqual(channel.code, HTTPStatus.BAD_REQUEST, channel.result)
@@ -100,7 +99,7 @@ class PasswordPolicyTestCase(unittest.HomeserverTestCase):
         )
 
     def test_password_no_digit(self) -> None:
-        request_data = json.dumps({"username": "kermit", "password": "longerpassword"})
+        request_data = {"username": "kermit", "password": "longerpassword"}
         channel = self.make_request("POST", self.register_url, request_data)
 
         self.assertEqual(channel.code, HTTPStatus.BAD_REQUEST, channel.result)
@@ -111,7 +110,7 @@ class PasswordPolicyTestCase(unittest.HomeserverTestCase):
         )
 
     def test_password_no_symbol(self) -> None:
-        request_data = json.dumps({"username": "kermit", "password": "l0ngerpassword"})
+        request_data = {"username": "kermit", "password": "l0ngerpassword"}
         channel = self.make_request("POST", self.register_url, request_data)
 
         self.assertEqual(channel.code, HTTPStatus.BAD_REQUEST, channel.result)
@@ -122,7 +121,7 @@ class PasswordPolicyTestCase(unittest.HomeserverTestCase):
         )
 
     def test_password_no_uppercase(self) -> None:
-        request_data = json.dumps({"username": "kermit", "password": "l0ngerpassword!"})
+        request_data = {"username": "kermit", "password": "l0ngerpassword!"}
         channel = self.make_request("POST", self.register_url, request_data)
 
         self.assertEqual(channel.code, HTTPStatus.BAD_REQUEST, channel.result)
@@ -133,7 +132,7 @@ class PasswordPolicyTestCase(unittest.HomeserverTestCase):
         )
 
     def test_password_no_lowercase(self) -> None:
-        request_data = json.dumps({"username": "kermit", "password": "L0NGERPASSWORD!"})
+        request_data = {"username": "kermit", "password": "L0NGERPASSWORD!"}
         channel = self.make_request("POST", self.register_url, request_data)
 
         self.assertEqual(channel.code, HTTPStatus.BAD_REQUEST, channel.result)
@@ -144,7 +143,7 @@ class PasswordPolicyTestCase(unittest.HomeserverTestCase):
         )
 
     def test_password_compliant(self) -> None:
-        request_data = json.dumps({"username": "kermit", "password": "L0ngerpassword!"})
+        request_data = {"username": "kermit", "password": "L0ngerpassword!"}
         channel = self.make_request("POST", self.register_url, request_data)
 
         # Getting a 401 here means the password has passed validation and the server has
@@ -161,16 +160,14 @@ class PasswordPolicyTestCase(unittest.HomeserverTestCase):
         user_id = self.register_user("kermit", compliant_password)
         tok = self.login("kermit", compliant_password)
 
-        request_data = json.dumps(
-            {
-                "new_password": not_compliant_password,
-                "auth": {
-                    "password": compliant_password,
-                    "type": LoginType.PASSWORD,
-                    "user": user_id,
-                },
-            }
-        )
+        request_data = {
+            "new_password": not_compliant_password,
+            "auth": {
+                "password": compliant_password,
+                "type": LoginType.PASSWORD,
+                "user": user_id,
+            },
+        }
         channel = self.make_request(
             "POST",
             "/_matrix/client/r0/account/password",
diff --git a/tests/rest/client/test_register.py b/tests/rest/client/test_register.py
index cb27458746..071b488cc0 100644
--- a/tests/rest/client/test_register.py
+++ b/tests/rest/client/test_register.py
@@ -14,7 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import datetime
-import json
 import os
 from typing import Any, Dict, List, Tuple
 
@@ -62,9 +61,10 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
         )
 
         self.hs.get_datastores().main.services_cache.append(appservice)
-        request_data = json.dumps(
-            {"username": "as_user_kermit", "type": APP_SERVICE_REGISTRATION_TYPE}
-        )
+        request_data = {
+            "username": "as_user_kermit",
+            "type": APP_SERVICE_REGISTRATION_TYPE,
+        }
 
         channel = self.make_request(
             b"POST", self.url + b"?access_token=i_am_an_app_service", request_data
@@ -85,7 +85,7 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
         )
 
         self.hs.get_datastores().main.services_cache.append(appservice)
-        request_data = json.dumps({"username": "as_user_kermit"})
+        request_data = {"username": "as_user_kermit"}
 
         channel = self.make_request(
             b"POST", self.url + b"?access_token=i_am_an_app_service", request_data
@@ -95,9 +95,7 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
 
     def test_POST_appservice_registration_invalid(self) -> None:
         self.appservice = None  # no application service exists
-        request_data = json.dumps(
-            {"username": "kermit", "type": APP_SERVICE_REGISTRATION_TYPE}
-        )
+        request_data = {"username": "kermit", "type": APP_SERVICE_REGISTRATION_TYPE}
         channel = self.make_request(
             b"POST", self.url + b"?access_token=i_am_an_app_service", request_data
         )
@@ -105,14 +103,14 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
         self.assertEqual(channel.result["code"], b"401", channel.result)
 
     def test_POST_bad_password(self) -> None:
-        request_data = json.dumps({"username": "kermit", "password": 666})
+        request_data = {"username": "kermit", "password": 666}
         channel = self.make_request(b"POST", self.url, request_data)
 
         self.assertEqual(channel.result["code"], b"400", channel.result)
         self.assertEqual(channel.json_body["error"], "Invalid password")
 
     def test_POST_bad_username(self) -> None:
-        request_data = json.dumps({"username": 777, "password": "monkey"})
+        request_data = {"username": 777, "password": "monkey"}
         channel = self.make_request(b"POST", self.url, request_data)
 
         self.assertEqual(channel.result["code"], b"400", channel.result)
@@ -121,13 +119,12 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
     def test_POST_user_valid(self) -> None:
         user_id = "@kermit:test"
         device_id = "frogfone"
-        params = {
+        request_data = {
             "username": "kermit",
             "password": "monkey",
             "device_id": device_id,
             "auth": {"type": LoginType.DUMMY},
         }
-        request_data = json.dumps(params)
         channel = self.make_request(b"POST", self.url, request_data)
 
         det_data = {
@@ -140,7 +137,7 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
 
     @override_config({"enable_registration": False})
     def test_POST_disabled_registration(self) -> None:
-        request_data = json.dumps({"username": "kermit", "password": "monkey"})
+        request_data = {"username": "kermit", "password": "monkey"}
         self.auth_result = (None, {"username": "kermit", "password": "monkey"}, None)
 
         channel = self.make_request(b"POST", self.url, request_data)
@@ -188,13 +185,12 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
     @override_config({"rc_registration": {"per_second": 0.17, "burst_count": 5}})
     def test_POST_ratelimiting(self) -> None:
         for i in range(0, 6):
-            params = {
+            request_data = {
                 "username": "kermit" + str(i),
                 "password": "monkey",
                 "device_id": "frogfone",
                 "auth": {"type": LoginType.DUMMY},
             }
-            request_data = json.dumps(params)
             channel = self.make_request(b"POST", self.url, request_data)
 
             if i == 5:
@@ -234,7 +230,7 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
         }
 
         # Request without auth to get flows and session
-        channel = self.make_request(b"POST", self.url, json.dumps(params))
+        channel = self.make_request(b"POST", self.url, params)
         self.assertEqual(channel.result["code"], b"401", channel.result)
         flows = channel.json_body["flows"]
         # Synapse adds a dummy stage to differentiate flows where otherwise one
@@ -251,8 +247,7 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
             "token": token,
             "session": session,
         }
-        request_data = json.dumps(params)
-        channel = self.make_request(b"POST", self.url, request_data)
+        channel = self.make_request(b"POST", self.url, params)
         self.assertEqual(channel.result["code"], b"401", channel.result)
         completed = channel.json_body["completed"]
         self.assertCountEqual([LoginType.REGISTRATION_TOKEN], completed)
@@ -262,8 +257,7 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
             "type": LoginType.DUMMY,
             "session": session,
         }
-        request_data = json.dumps(params)
-        channel = self.make_request(b"POST", self.url, request_data)
+        channel = self.make_request(b"POST", self.url, params)
         det_data = {
             "user_id": f"@{username}:{self.hs.hostname}",
             "home_server": self.hs.hostname,
@@ -290,7 +284,7 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
             "password": "monkey",
         }
         # Request without auth to get session
-        channel = self.make_request(b"POST", self.url, json.dumps(params))
+        channel = self.make_request(b"POST", self.url, params)
         session = channel.json_body["session"]
 
         # Test with token param missing (invalid)
@@ -298,21 +292,21 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
             "type": LoginType.REGISTRATION_TOKEN,
             "session": session,
         }
-        channel = self.make_request(b"POST", self.url, json.dumps(params))
+        channel = self.make_request(b"POST", self.url, params)
         self.assertEqual(channel.result["code"], b"401", channel.result)
         self.assertEqual(channel.json_body["errcode"], Codes.MISSING_PARAM)
         self.assertEqual(channel.json_body["completed"], [])
 
         # Test with non-string (invalid)
         params["auth"]["token"] = 1234
-        channel = self.make_request(b"POST", self.url, json.dumps(params))
+        channel = self.make_request(b"POST", self.url, params)
         self.assertEqual(channel.result["code"], b"401", channel.result)
         self.assertEqual(channel.json_body["errcode"], Codes.INVALID_PARAM)
         self.assertEqual(channel.json_body["completed"], [])
 
         # Test with unknown token (invalid)
         params["auth"]["token"] = "1234"
-        channel = self.make_request(b"POST", self.url, json.dumps(params))
+        channel = self.make_request(b"POST", self.url, params)
         self.assertEqual(channel.result["code"], b"401", channel.result)
         self.assertEqual(channel.json_body["errcode"], Codes.UNAUTHORIZED)
         self.assertEqual(channel.json_body["completed"], [])
@@ -337,9 +331,9 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
         params1: JsonDict = {"username": "bert", "password": "monkey"}
         params2: JsonDict = {"username": "ernie", "password": "monkey"}
         # Do 2 requests without auth to get two session IDs
-        channel1 = self.make_request(b"POST", self.url, json.dumps(params1))
+        channel1 = self.make_request(b"POST", self.url, params1)
         session1 = channel1.json_body["session"]
-        channel2 = self.make_request(b"POST", self.url, json.dumps(params2))
+        channel2 = self.make_request(b"POST", self.url, params2)
         session2 = channel2.json_body["session"]
 
         # Use token with session1 and check `pending` is 1
@@ -348,9 +342,9 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
             "token": token,
             "session": session1,
         }
-        self.make_request(b"POST", self.url, json.dumps(params1))
+        self.make_request(b"POST", self.url, params1)
         # Repeat request to make sure pending isn't increased again
-        self.make_request(b"POST", self.url, json.dumps(params1))
+        self.make_request(b"POST", self.url, params1)
         pending = self.get_success(
             store.db_pool.simple_select_one_onecol(
                 "registration_tokens",
@@ -366,14 +360,14 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
             "token": token,
             "session": session2,
         }
-        channel = self.make_request(b"POST", self.url, json.dumps(params2))
+        channel = self.make_request(b"POST", self.url, params2)
         self.assertEqual(channel.result["code"], b"401", channel.result)
         self.assertEqual(channel.json_body["errcode"], Codes.UNAUTHORIZED)
         self.assertEqual(channel.json_body["completed"], [])
 
         # Complete registration with session1
         params1["auth"]["type"] = LoginType.DUMMY
-        self.make_request(b"POST", self.url, json.dumps(params1))
+        self.make_request(b"POST", self.url, params1)
         # Check pending=0 and completed=1
         res = self.get_success(
             store.db_pool.simple_select_one(
@@ -386,7 +380,7 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
         self.assertEqual(res["completed"], 1)
 
         # Check auth still fails when using token with session2
-        channel = self.make_request(b"POST", self.url, json.dumps(params2))
+        channel = self.make_request(b"POST", self.url, params2)
         self.assertEqual(channel.result["code"], b"401", channel.result)
         self.assertEqual(channel.json_body["errcode"], Codes.UNAUTHORIZED)
         self.assertEqual(channel.json_body["completed"], [])
@@ -411,7 +405,7 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
         )
         params: JsonDict = {"username": "kermit", "password": "monkey"}
         # Request without auth to get session
-        channel = self.make_request(b"POST", self.url, json.dumps(params))
+        channel = self.make_request(b"POST", self.url, params)
         session = channel.json_body["session"]
 
         # Check authentication fails with expired token
@@ -420,7 +414,7 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
             "token": token,
             "session": session,
         }
-        channel = self.make_request(b"POST", self.url, json.dumps(params))
+        channel = self.make_request(b"POST", self.url, params)
         self.assertEqual(channel.result["code"], b"401", channel.result)
         self.assertEqual(channel.json_body["errcode"], Codes.UNAUTHORIZED)
         self.assertEqual(channel.json_body["completed"], [])
@@ -435,7 +429,7 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
         )
 
         # Check authentication succeeds
-        channel = self.make_request(b"POST", self.url, json.dumps(params))
+        channel = self.make_request(b"POST", self.url, params)
         completed = channel.json_body["completed"]
         self.assertCountEqual([LoginType.REGISTRATION_TOKEN], completed)
 
@@ -460,9 +454,9 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
         # Do 2 requests without auth to get two session IDs
         params1: JsonDict = {"username": "bert", "password": "monkey"}
         params2: JsonDict = {"username": "ernie", "password": "monkey"}
-        channel1 = self.make_request(b"POST", self.url, json.dumps(params1))
+        channel1 = self.make_request(b"POST", self.url, params1)
         session1 = channel1.json_body["session"]
-        channel2 = self.make_request(b"POST", self.url, json.dumps(params2))
+        channel2 = self.make_request(b"POST", self.url, params2)
         session2 = channel2.json_body["session"]
 
         # Use token with both sessions
@@ -471,18 +465,18 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
             "token": token,
             "session": session1,
         }
-        self.make_request(b"POST", self.url, json.dumps(params1))
+        self.make_request(b"POST", self.url, params1)
 
         params2["auth"] = {
             "type": LoginType.REGISTRATION_TOKEN,
             "token": token,
             "session": session2,
         }
-        self.make_request(b"POST", self.url, json.dumps(params2))
+        self.make_request(b"POST", self.url, params2)
 
         # Complete registration with session1
         params1["auth"]["type"] = LoginType.DUMMY
-        self.make_request(b"POST", self.url, json.dumps(params1))
+        self.make_request(b"POST", self.url, params1)
 
         # Check `result` of registration token stage for session1 is `True`
         result1 = self.get_success(
@@ -550,7 +544,7 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
 
         # Do request without auth to get a session ID
         params: JsonDict = {"username": "kermit", "password": "monkey"}
-        channel = self.make_request(b"POST", self.url, json.dumps(params))
+        channel = self.make_request(b"POST", self.url, params)
         session = channel.json_body["session"]
 
         # Use token
@@ -559,7 +553,7 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
             "token": token,
             "session": session,
         }
-        self.make_request(b"POST", self.url, json.dumps(params))
+        self.make_request(b"POST", self.url, params)
 
         # Delete token
         self.get_success(
@@ -827,8 +821,7 @@ class AccountValidityTestCase(unittest.HomeserverTestCase):
         admin_tok = self.login("admin", "adminpassword")
 
         url = "/_synapse/admin/v1/account_validity/validity"
-        params = {"user_id": user_id}
-        request_data = json.dumps(params)
+        request_data = {"user_id": user_id}
         channel = self.make_request(b"POST", url, request_data, access_token=admin_tok)
         self.assertEqual(channel.result["code"], b"200", channel.result)
 
@@ -845,12 +838,11 @@ class AccountValidityTestCase(unittest.HomeserverTestCase):
         admin_tok = self.login("admin", "adminpassword")
 
         url = "/_synapse/admin/v1/account_validity/validity"
-        params = {
+        request_data = {
             "user_id": user_id,
             "expiration_ts": 0,
             "enable_renewal_emails": False,
         }
-        request_data = json.dumps(params)
         channel = self.make_request(b"POST", url, request_data, access_token=admin_tok)
         self.assertEqual(channel.result["code"], b"200", channel.result)
 
@@ -870,12 +862,11 @@ class AccountValidityTestCase(unittest.HomeserverTestCase):
         admin_tok = self.login("admin", "adminpassword")
 
         url = "/_synapse/admin/v1/account_validity/validity"
-        params = {
+        request_data = {
             "user_id": user_id,
             "expiration_ts": 0,
             "enable_renewal_emails": False,
         }
-        request_data = json.dumps(params)
         channel = self.make_request(b"POST", url, request_data, access_token=admin_tok)
         self.assertEqual(channel.result["code"], b"200", channel.result)
 
@@ -1041,16 +1032,14 @@ class AccountValidityRenewalByEmailTestCase(unittest.HomeserverTestCase):
 
         (user_id, tok) = self.create_user()
 
-        request_data = json.dumps(
-            {
-                "auth": {
-                    "type": "m.login.password",
-                    "user": user_id,
-                    "password": "monkey",
-                },
-                "erase": False,
-            }
-        )
+        request_data = {
+            "auth": {
+                "type": "m.login.password",
+                "user": user_id,
+                "password": "monkey",
+            },
+            "erase": False,
+        }
         channel = self.make_request(
             "POST", "account/deactivate", request_data, access_token=tok
         )
diff --git a/tests/rest/client/test_report_event.py b/tests/rest/client/test_report_event.py
index 20a259fc43..ad0d0209f7 100644
--- a/tests/rest/client/test_report_event.py
+++ b/tests/rest/client/test_report_event.py
@@ -12,8 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import json
-
 from twisted.test.proto_helpers import MemoryReactor
 
 import synapse.rest.admin
@@ -77,10 +75,7 @@ class ReportEventTestCase(unittest.HomeserverTestCase):
 
     def _assert_status(self, response_status: int, data: JsonDict) -> None:
         channel = self.make_request(
-            "POST",
-            self.report_path,
-            json.dumps(data),
-            access_token=self.other_user_tok,
+            "POST", self.report_path, data, access_token=self.other_user_tok
         )
         self.assertEqual(
             response_status, int(channel.result["code"]), msg=channel.result["body"]
diff --git a/tests/rest/client/test_rooms.py b/tests/rest/client/test_rooms.py
index 4c6b3decd8..c60ca604e9 100644
--- a/tests/rest/client/test_rooms.py
+++ b/tests/rest/client/test_rooms.py
@@ -770,16 +770,14 @@ class RoomsCreateTestCase(RoomBase):
 
         # Build the request's content. We use local MXIDs because invites over federation
         # are more difficult to mock.
-        content = json.dumps(
-            {
-                "invite": [
-                    "@alice1:red",
-                    "@alice2:red",
-                    "@alice3:red",
-                    "@alice4:red",
-                ]
-            }
-        ).encode("utf8")
+        content = {
+            "invite": [
+                "@alice1:red",
+                "@alice2:red",
+                "@alice3:red",
+                "@alice4:red",
+            ]
+        }
 
         # Test that the invites are correctly ratelimited.
         channel = self.make_request("POST", "/createRoom", content)
@@ -2251,8 +2249,7 @@ class PerRoomProfilesForbiddenTestCase(unittest.HomeserverTestCase):
 
         # Set a profile for the test user
         self.displayname = "test user"
-        data = {"displayname": self.displayname}
-        request_data = json.dumps(data)
+        request_data = {"displayname": self.displayname}
         channel = self.make_request(
             "PUT",
             "/_matrix/client/r0/profile/%s/displayname" % (self.user_id,),
@@ -2264,8 +2261,7 @@ class PerRoomProfilesForbiddenTestCase(unittest.HomeserverTestCase):
         self.room_id = self.helper.create_room_as(self.user_id, tok=self.tok)
 
     def test_per_room_profile_forbidden(self) -> None:
-        data = {"membership": "join", "displayname": "other test user"}
-        request_data = json.dumps(data)
+        request_data = {"membership": "join", "displayname": "other test user"}
         channel = self.make_request(
             "PUT",
             "/_matrix/client/r0/rooms/%s/state/m.room.member/%s"
@@ -2605,16 +2601,14 @@ class LabelsTestCase(unittest.HomeserverTestCase):
 
     def test_search_filter_labels(self) -> None:
         """Test that we can filter by a label on a /search request."""
-        request_data = json.dumps(
-            {
-                "search_categories": {
-                    "room_events": {
-                        "search_term": "label",
-                        "filter": self.FILTER_LABELS,
-                    }
+        request_data = {
+            "search_categories": {
+                "room_events": {
+                    "search_term": "label",
+                    "filter": self.FILTER_LABELS,
                 }
             }
-        )
+        }
 
         self._send_labelled_messages_in_room()
 
@@ -2642,16 +2636,14 @@ class LabelsTestCase(unittest.HomeserverTestCase):
 
     def test_search_filter_not_labels(self) -> None:
         """Test that we can filter by the absence of a label on a /search request."""
-        request_data = json.dumps(
-            {
-                "search_categories": {
-                    "room_events": {
-                        "search_term": "label",
-                        "filter": self.FILTER_NOT_LABELS,
-                    }
+        request_data = {
+            "search_categories": {
+                "room_events": {
+                    "search_term": "label",
+                    "filter": self.FILTER_NOT_LABELS,
                 }
             }
-        )
+        }
 
         self._send_labelled_messages_in_room()
 
@@ -2691,16 +2683,14 @@ class LabelsTestCase(unittest.HomeserverTestCase):
         """Test that we can filter by both a label and the absence of another label on a
         /search request.
         """
-        request_data = json.dumps(
-            {
-                "search_categories": {
-                    "room_events": {
-                        "search_term": "label",
-                        "filter": self.FILTER_LABELS_NOT_LABELS,
-                    }
+        request_data = {
+            "search_categories": {
+                "room_events": {
+                    "search_term": "label",
+                    "filter": self.FILTER_LABELS_NOT_LABELS,
                 }
             }
-        )
+        }
 
         self._send_labelled_messages_in_room()
 
@@ -3145,8 +3135,7 @@ class RoomAliasListTestCase(unittest.HomeserverTestCase):
 
     def _set_alias_via_directory(self, alias: str, expected_code: int = 200) -> None:
         url = "/_matrix/client/r0/directory/room/" + alias
-        data = {"room_id": self.room_id}
-        request_data = json.dumps(data)
+        request_data = {"room_id": self.room_id}
 
         channel = self.make_request(
             "PUT", url, request_data, access_token=self.room_owner_tok
@@ -3175,8 +3164,7 @@ class RoomCanonicalAliasTestCase(unittest.HomeserverTestCase):
 
     def _set_alias_via_directory(self, alias: str, expected_code: int = 200) -> None:
         url = "/_matrix/client/r0/directory/room/" + alias
-        data = {"room_id": self.room_id}
-        request_data = json.dumps(data)
+        request_data = {"room_id": self.room_id}
 
         channel = self.make_request(
             "PUT", url, request_data, access_token=self.room_owner_tok
@@ -3202,7 +3190,7 @@ class RoomCanonicalAliasTestCase(unittest.HomeserverTestCase):
         channel = self.make_request(
             "PUT",
             "rooms/%s/state/m.room.canonical_alias" % (self.room_id,),
-            json.dumps(content),
+            content,
             access_token=self.room_owner_tok,
         )
         self.assertEqual(channel.code, expected_code, channel.result)
diff --git a/tests/rest/client/test_sync.py b/tests/rest/client/test_sync.py
index e3efd1f1b0..b085c50356 100644
--- a/tests/rest/client/test_sync.py
+++ b/tests/rest/client/test_sync.py
@@ -606,11 +606,10 @@ class UnreadMessagesTestCase(unittest.HomeserverTestCase):
         self._check_unread_count(1)
 
         # Send a read receipt to tell the server we've read the latest event.
-        body = json.dumps({ReceiptTypes.READ: res["event_id"]}).encode("utf8")
         channel = self.make_request(
             "POST",
             f"/rooms/{self.room_id}/read_markers",
-            body,
+            {ReceiptTypes.READ: res["event_id"]},
             access_token=self.tok,
         )
         self.assertEqual(channel.code, 200, channel.json_body)
diff --git a/tests/rest/client/utils.py b/tests/rest/client/utils.py
index 93f749744d..105d418698 100644
--- a/tests/rest/client/utils.py
+++ b/tests/rest/client/utils.py
@@ -136,7 +136,7 @@ class RestHelper:
             self.site,
             "POST",
             path,
-            json.dumps(content).encode("utf8"),
+            content,
             custom_headers=custom_headers,
         )
 
@@ -210,7 +210,7 @@ class RestHelper:
             self.site,
             "POST",
             path,
-            json.dumps(data).encode("utf8"),
+            data,
         )
 
         assert (
@@ -309,7 +309,7 @@ class RestHelper:
             self.site,
             "PUT",
             path,
-            json.dumps(data).encode("utf8"),
+            data,
         )
 
         assert (
@@ -392,7 +392,7 @@ class RestHelper:
             self.site,
             "PUT",
             path,
-            json.dumps(content or {}).encode("utf8"),
+            content or {},
             custom_headers=custom_headers,
         )
 
diff --git a/tests/test_terms_auth.py b/tests/test_terms_auth.py
index 37fada5c53..d3c13cf14c 100644
--- a/tests/test_terms_auth.py
+++ b/tests/test_terms_auth.py
@@ -12,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import json
 from unittest.mock import Mock
 
 from twisted.test.proto_helpers import MemoryReactorClock
@@ -51,7 +50,7 @@ class TermsTestCase(unittest.HomeserverTestCase):
 
     def test_ui_auth(self):
         # Do a UI auth request
-        request_data = json.dumps({"username": "kermit", "password": "monkey"})
+        request_data = {"username": "kermit", "password": "monkey"}
         channel = self.make_request(b"POST", self.url, request_data)
 
         self.assertEqual(channel.result["code"], b"401", channel.result)
@@ -82,16 +81,14 @@ class TermsTestCase(unittest.HomeserverTestCase):
         self.assertDictContainsSubset(channel.json_body["params"], expected_params)
 
         # We have to complete the dummy auth stage before completing the terms stage
-        request_data = json.dumps(
-            {
-                "username": "kermit",
-                "password": "monkey",
-                "auth": {
-                    "session": channel.json_body["session"],
-                    "type": "m.login.dummy",
-                },
-            }
-        )
+        request_data = {
+            "username": "kermit",
+            "password": "monkey",
+            "auth": {
+                "session": channel.json_body["session"],
+                "type": "m.login.dummy",
+            },
+        }
 
         self.registration_handler.check_username = Mock(return_value=True)
 
@@ -102,16 +99,14 @@ class TermsTestCase(unittest.HomeserverTestCase):
         self.assertEqual(channel.result["code"], b"401", channel.result)
 
         # Finish the UI auth for terms
-        request_data = json.dumps(
-            {
-                "username": "kermit",
-                "password": "monkey",
-                "auth": {
-                    "session": channel.json_body["session"],
-                    "type": "m.login.terms",
-                },
-            }
-        )
+        request_data = {
+            "username": "kermit",
+            "password": "monkey",
+            "auth": {
+                "session": channel.json_body["session"],
+                "type": "m.login.terms",
+            },
+        }
         channel = self.make_request(b"POST", self.url, request_data)
 
         # We're interested in getting a response that looks like a successful
diff --git a/tests/unittest.py b/tests/unittest.py
index 7b97a4bf6e..9f1ff774a8 100644
--- a/tests/unittest.py
+++ b/tests/unittest.py
@@ -16,7 +16,6 @@
 import gc
 import hashlib
 import hmac
-import json
 import logging
 import secrets
 import time
@@ -619,20 +618,16 @@ class HomeserverTestCase(TestCase):
         want_mac.update(nonce.encode("ascii") + b"\x00" + nonce_str)
         want_mac_digest = want_mac.hexdigest()
 
-        body = json.dumps(
-            {
-                "nonce": nonce,
-                "username": username,
-                "displayname": displayname,
-                "password": password,
-                "admin": admin,
-                "mac": want_mac_digest,
-                "inhibit_login": True,
-            }
-        )
-        channel = self.make_request(
-            "POST", "/_synapse/admin/v1/register", body.encode("utf8")
-        )
+        body = {
+            "nonce": nonce,
+            "username": username,
+            "displayname": displayname,
+            "password": password,
+            "admin": admin,
+            "mac": want_mac_digest,
+            "inhibit_login": True,
+        }
+        channel = self.make_request("POST", "/_synapse/admin/v1/register", body)
         self.assertEqual(channel.code, 200, channel.json_body)
 
         user_id = channel.json_body["user_id"]
@@ -676,9 +671,7 @@ class HomeserverTestCase(TestCase):
         custom_headers: Optional[Iterable[CustomHeaderType]] = None,
     ) -> str:
         """
-        Log in a user, and get an access token. Requires the Login API be
-        registered.
-
+        Log in a user, and get an access token. Requires the Login API be registered.
         """
         body = {"type": "m.login.password", "user": username, "password": password}
         if device_id:
@@ -687,7 +680,7 @@ class HomeserverTestCase(TestCase):
         channel = self.make_request(
             "POST",
             "/_matrix/client/r0/login",
-            json.dumps(body).encode("utf8"),
+            body,
             custom_headers=custom_headers,
         )
         self.assertEqual(channel.code, 200, channel.result)