Drop tautological priming-order unit test; cover retry_interval-None arc via e2e

The synthetic test called _mint_priming_event itself then asserted it was
stored first, which proves the test's own statement order rather than that
_handle_post_request mints before dispatch. The e2e test in test_hosting_resume.py
already pins the real contract through the production handler; dropping
retry_interval= from that test (it doesn't reconnect) also covers the
retry_interval-is-None branch via the real path.

Author: maxisbey

tests/interaction/transports/test_hosting_resume.py

@@ -130,7 +130,7 @@ async def burst(ctx: Context) -> str:
         await ctx.info("c")  # pyright: ignore[reportDeprecated]
         return "done"
 
-    async with mounted_app(mcp, event_store=store, retry_interval=0) as (http, _):
+    async with mounted_app(mcp, event_store=store) as (http, _):
         session_id = await initialize_via_http(http)
         with anyio.fail_after(5):
             async with http.stream(  # pragma: no branch

tests/server/test_streamable_http_router.py

@@ -17,18 +17,6 @@
 from mcp.types import JSONRPCMessage, JSONRPCResponse
 
 
-class _OrderTrackingStore(EventStore):
-    def __init__(self) -> None:
-        self.stored: list[tuple[StreamId, JSONRPCMessage | None]] = []
-
-    async def store_event(self, stream_id: StreamId, message: JSONRPCMessage | None) -> EventId:
-        self.stored.append((stream_id, message))
-        return str(len(self.stored))
-
-    async def replay_events_after(self, last_event_id: EventId, send_callback: EventCallback) -> StreamId | None:
-        raise NotImplementedError
-
-
 class _PrimingFailingStore(EventStore):
     async def store_event(self, stream_id: StreamId, message: JSONRPCMessage | None) -> EventId:
         raise RuntimeError("backend unavailable")
@@ -76,40 +64,6 @@ async def server_writes() -> None:
             await a_send.aclose()
 
 
-@pytest.mark.anyio
-async def test_priming_event_is_stored_before_any_routed_message() -> None:
-    """`_mint_priming_event` is awaited before the request is dispatched, so the
-    priming row precedes every `message_router` store for that stream regardless
-    of when `sse_writer` is scheduled.
-    """
-    store = _OrderTrackingStore()
-    transport = StreamableHTTPServerTransport(mcp_session_id="sid", is_json_response_enabled=False, event_store=store)
-    streams = transport._request_streams
-
-    async with transport.connect() as (_read_stream, write_stream):
-        # POST handler step: mint priming for "A" before dispatch.
-        priming = await transport._mint_priming_event("A", "2025-11-25")
-        assert priming is not None
-        streams["A"] = anyio.create_memory_object_stream[EventMessage](REQUEST_STREAM_BUFFER_SIZE)
-        a_send, a_recv = streams["A"]
-
-        # Server emits 5 messages for "A" with no sse_writer scheduled. Each
-        # write_stream.send() rendezvous-hands to message_router, which stores
-        # then deposits into A's buffer; reading them back proves the router
-        # has finished storing.
-        for i in range(5):
-            await write_stream.send(SessionMessage(JSONRPCResponse(jsonrpc="2.0", id="A", result={"n": i})))
-        with anyio.fail_after(5):
-            for _ in range(5):
-                await a_recv.receive()
-        await a_recv.aclose()
-        await a_send.aclose()
-
-    assert store.stored[0] == ("A", None)
-    assert [sid for sid, _ in store.stored] == ["A"] * 6
-    assert all(msg is not None for _, msg in store.stored[1:])
-
-
 @pytest.mark.anyio
 async def test_priming_store_failure_leaves_no_per_request_state() -> None:
     """`EventStore.store_event` raising on the priming row must not leak per-request entries."""