diff --git a/changelog.d/8759.misc b/changelog.d/8759.misc
new file mode 100644
index 000000000000..54502e9b9029
--- /dev/null
+++ b/changelog.d/8759.misc
@@ -0,0 +1 @@
+Refactor test utilities for injecting HTTP requests.
diff --git a/tests/replication/_base.py b/tests/replication/_base.py
index 5c633ac6dff8..bc56b13dcddf 100644
--- a/tests/replication/_base.py
+++ b/tests/replication/_base.py
@@ -240,8 +240,8 @@ def setUp(self):
             lambda: self._handle_http_replication_attempt(self.hs, 8765),
         )
 
-    def create_test_json_resource(self):
-        """Overrides `HomeserverTestCase.create_test_json_resource`.
+    def create_test_resource(self):
+        """Overrides `HomeserverTestCase.create_test_resource`.
         """
         # We override this so that it automatically registers all the HTTP
         # replication servlets, without having to explicitly do that in all
diff --git a/tests/rest/admin/test_admin.py b/tests/rest/admin/test_admin.py
index 0f1144fe1e40..6804f9337f10 100644
--- a/tests/rest/admin/test_admin.py
+++ b/tests/rest/admin/test_admin.py
@@ -35,7 +35,7 @@
 class VersionTestCase(unittest.HomeserverTestCase):
     url = "/_synapse/admin/v1/server_version"
 
-    def create_test_json_resource(self):
+    def create_test_resource(self):
         resource = JsonResource(self.hs)
         VersionServlet(self.hs).register(resource)
         return resource
diff --git a/tests/rest/key/v2/test_remote_key_resource.py b/tests/rest/key/v2/test_remote_key_resource.py
index 6850c666be67..6671cbd32def 100644
--- a/tests/rest/key/v2/test_remote_key_resource.py
+++ b/tests/rest/key/v2/test_remote_key_resource.py
@@ -41,7 +41,7 @@ def make_homeserver(self, reactor, clock):
         self.http_client = Mock()
         return self.setup_test_homeserver(http_client=self.http_client)
 
-    def create_test_json_resource(self):
+    def create_test_resource(self):
         return create_resource_tree(
             {"/_matrix/key/v2": KeyApiV2Resource(self.hs)}, root_resource=NoResource()
         )
diff --git a/tests/rest/test_health.py b/tests/rest/test_health.py
index 2d021f656542..f4d06e2200af 100644
--- a/tests/rest/test_health.py
+++ b/tests/rest/test_health.py
@@ -20,11 +20,9 @@
 
 
 class HealthCheckTests(unittest.HomeserverTestCase):
-    def setUp(self):
-        super().setUp()
-
+    def create_test_resource(self):
         # replace the JsonResource with a HealthResource.
-        self.resource = HealthResource()
+        return HealthResource()
 
     def test_health(self):
         request, channel = self.make_request("GET", "/health", shorthand=False)
diff --git a/tests/rest/test_well_known.py b/tests/rest/test_well_known.py
index dcd65c2a503f..a3746e713023 100644
--- a/tests/rest/test_well_known.py
+++ b/tests/rest/test_well_known.py
@@ -20,11 +20,9 @@
 
 
 class WellKnownTests(unittest.HomeserverTestCase):
-    def setUp(self):
-        super().setUp()
-
+    def create_test_resource(self):
         # replace the JsonResource with a WellKnownResource
-        self.resource = WellKnownResource(self.hs)
+        return WellKnownResource(self.hs)
 
     def test_well_known(self):
         self.hs.config.public_baseurl = "https://tesths"
diff --git a/tests/unittest.py b/tests/unittest.py
index e36ac8919606..c630760e513e 100644
--- a/tests/unittest.py
+++ b/tests/unittest.py
@@ -30,6 +30,7 @@
 from twisted.python.failure import Failure
 from twisted.python.threadpool import ThreadPool
 from twisted.trial import unittest
+from twisted.web.resource import Resource
 
 from synapse.api.constants import EventTypes, Membership
 from synapse.config.homeserver import HomeServerConfig
@@ -239,10 +240,8 @@ def setUp(self):
         if not isinstance(self.hs, HomeServer):
             raise Exception("A homeserver wasn't returned, but %r" % (self.hs,))
 
-        # Register the resources
-        self.resource = self.create_test_json_resource()
-
-        # create a site to wrap the resource.
+        # create the root resource, and a site to wrap it.
+        self.resource = self.create_test_resource()
         self.site = SynapseSite(
             logger_name="synapse.access.http.fake",
             site_tag=self.hs.config.server.server_name,
@@ -323,15 +322,12 @@ def make_homeserver(self, reactor, clock):
         hs = self.setup_test_homeserver()
         return hs
 
-    def create_test_json_resource(self):
+    def create_test_resource(self) -> Resource:
         """
-        Create a test JsonResource, with the relevant servlets registerd to it
-
-        The default implementation calls each function in `servlets` to do the
-        registration.
+        Create a the root resource for the test server.
 
-        Returns:
-            JsonResource:
+        The default implementation creates a JsonResource and calls each function in
+        `servlets` to register servletes against it
         """
         resource = JsonResource(self.hs)