From 776ad3e5e9cb082a3c7d205da29b64e946a8176c Mon Sep 17 00:00:00 2001
From: David Robertson <davidr@element.io>
Date: Mon, 29 Nov 2021 11:11:46 +0000
Subject: [PATCH] Add a test case for the SendJoinParser (#11441)

This would have caught the bug #11438 introduced in #11217 and fixed in #11439.
---
 changelog.d/11441.misc                    |  1 +
 mypy.ini                                  |  4 ++
 tests/federation/transport/test_client.py | 50 +++++++++++++++++++++++
 3 files changed, 55 insertions(+)
 create mode 100644 changelog.d/11441.misc
 create mode 100644 tests/federation/transport/test_client.py

diff --git a/changelog.d/11441.misc b/changelog.d/11441.misc
new file mode 100644
index 000000000000..1baef41d7071
--- /dev/null
+++ b/changelog.d/11441.misc
@@ -0,0 +1 @@
+Fix a bug introduced in 1.47.0 where `send_join` could fail due to an outdated `ijson` version.
\ No newline at end of file
diff --git a/mypy.ini b/mypy.ini
index eb3976e74c42..f3361c00bcaa 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -222,6 +222,10 @@ disallow_untyped_defs = True
 [mypy-tests.rest.client.test_directory]
 disallow_untyped_defs = True
 
+[mypy-tests.federation.transport.test_client]
+disallow_untyped_defs = True
+
+
 ;; Dependencies without annotations
 ;; Before ignoring a module, check to see if type stubs are available.
 ;; The `typeshed` project maintains stubs here:
diff --git a/tests/federation/transport/test_client.py b/tests/federation/transport/test_client.py
new file mode 100644
index 000000000000..0b191599618a
--- /dev/null
+++ b/tests/federation/transport/test_client.py
@@ -0,0 +1,50 @@
+import json
+
+from synapse.api.room_versions import RoomVersions
+from synapse.federation.transport.client import SendJoinParser
+
+from tests.unittest import TestCase
+
+
+class SendJoinParserTestCase(TestCase):
+    def test_two_writes(self) -> None:
+        """Test that the parser can sensibly deserialise an input given in two slices."""
+        parser = SendJoinParser(RoomVersions.V1, True)
+        parent_event = {
+            "content": {
+                "see_room_version_spec": "The event format changes depending on the room version."
+            },
+            "event_id": "$authparent",
+            "room_id": "!somewhere:example.org",
+            "type": "m.room.minimal_pdu",
+        }
+        state = {
+            "content": {
+                "see_room_version_spec": "The event format changes depending on the room version."
+            },
+            "event_id": "$DoNotThinkAboutTheEvent",
+            "room_id": "!somewhere:example.org",
+            "type": "m.room.minimal_pdu",
+        }
+        response = [
+            200,
+            {
+                "auth_chain": [parent_event],
+                "origin": "matrix.org",
+                "state": [state],
+            },
+        ]
+        serialised_response = json.dumps(response).encode()
+
+        # Send data to the parser
+        parser.write(serialised_response[:100])
+        parser.write(serialised_response[100:])
+
+        # Retrieve the parsed SendJoinResponse
+        parsed_response = parser.finish()
+
+        # Sanity check the parsing gave us sensible data.
+        self.assertEqual(len(parsed_response.auth_events), 1, parsed_response)
+        self.assertEqual(len(parsed_response.state), 1, parsed_response)
+        self.assertEqual(parsed_response.event_dict, {}, parsed_response)
+        self.assertIsNone(parsed_response.event, parsed_response)