Add `Server` to Access-Control-Expose-Headers header (#15908)

changelog.d/15908.misc

@@ -0,0 +1 @@
+Add `Server` to Access-Control-Expose-Headers header.

synapse/http/server.py

@@ -910,7 +910,7 @@ def set_cors_headers(request: SynapseRequest) -> None:
         )
         request.setHeader(
             b"Access-Control-Expose-Headers",
-            b"Synapse-Trace-Id",
+            b"Synapse-Trace-Id, Server",
         )
 
 

tests/test_server.py

@@ -268,7 +268,7 @@ class OptionsResourceTests(unittest.TestCase):
         )
         self.assertEqual(
             channel.headers.getRawHeaders(b"Access-Control-Expose-Headers"),
-            [b"Synapse-Trace-Id"],
+            [b"Synapse-Trace-Id, Server"],
         )
 
     def _check_cors_msc3886_headers(self, channel: FakeChannel) -> None: