Fweinberger/sep 1699 test revise

[pcarleton]

3 changes to the test:

• Adds more logging (via INFO checks), so it's easier to tell from a run what happened / what went wrong
• Fixed an issue where the out-of-band "GET /" was causing a fail on including last-event-id (since the bare GET / doesn't have one)
• Switches from doing the priming on initialize to on a tool call. This was mostly to make it closer to a normal use case (e.g. the example client in the 1699 PR). I was going to also add progress notifications, but realized that defeats some of what this test is checking (i.e. that clients respond well to the polling)

Test Results

node dist/index.js server --url http://localhost:3000/mcp --scenario server-sse-polling

Running client scenario 'server-sse-polling' against server: http://localhost:3000/mcp
Results saved to results/server-server-sse-polling-2025-11-24T16-15-07-931Z
Checks:
2025-11-24T16:15:07.968Z [outgoing-request            ] INFO    Sending POST tools/call
2025-11-24T16:15:07.970Z [incoming-response           ] INFO    Received 200 response for POST
2025-11-24T16:15:07.971Z [incoming-sse-event          ] INFO    Received SSE priming event (id: 1219b3a8-9438-48b4-9953-8f335d81f262::1764000907969_9f79292d-3f5c-4945-b188-0c4a612023d8)
2025-11-24T16:15:07.971Z [stream-closed               ] INFO    POST SSE stream closed after 1 event(s)
2025-11-24T16:15:07.971Z [server-sse-priming-event    ] SUCCESS Server SHOULD send priming event with id and empty data on POST SSE streams
2025-11-24T16:15:07.971Z [server-sse-retry-field      ] SUCCESS Server SHOULD send retry field to control client reconnection timing
2025-11-24T16:15:07.971Z [outgoing-request            ] INFO    Sending GET request
2025-11-24T16:15:07.971Z [incoming-response           ] INFO    Received 200 response for GET
2025-11-24T16:15:08.071Z [incoming-sse-event          ] INFO    Received SSE event on GET reconnection stream (id: 1219b3a8-9438-48b4-9953-8f335d81f262::1764000908070_257f4329-d4bf-4893-8e56-1f0bf0090ebb)
2025-11-24T16:15:08.071Z [server-sse-disconnect-resume] SUCCESS Server closes SSE stream mid-call and resumes after client reconnects with Last-Event-ID

Test Results:
Passed: 3/3, 0 failed, 0 warnings

node dist/index.js client --scenario sse-retry --command "npx tsx examples/clients/typescript/sse-retry-test.ts"

Starting scenario: sse-retry
Executing client: npx tsx examples/clients/typescript/sse-retry-test.ts http://localhost:60386
Results saved to results/sse-retry-2025-11-24T16-15-13-228Z
Checks:
2025-11-24T16:15:13.978Z [incoming-request             ] INFO    Received POST request for / (method: initialize)
2025-11-24T16:15:13.978Z [outgoing-response            ] INFO    Sent initialize response

2025-11-24T16:15:13.983Z [incoming-request             ] INFO    Received POST request for / (method: notifications/initialized)
2025-11-24T16:15:13.984Z [incoming-request             ] INFO    Received GET request for /
2025-11-24T16:15:13.984Z [outgoing-sse-event           ] INFO    Sent SSE priming event on GET stream (id: event-1, retry: 500ms)
2025-11-24T16:15:13.986Z [incoming-request             ] INFO    Received POST request for / (method: tools/call)
2025-11-24T16:15:13.986Z [outgoing-sse-event           ] INFO    Sent SSE priming event for tools/call (id: event-2, retry: 500ms)
2025-11-24T16:15:14.038Z [outgoing-stream-close        ] INFO    Closed tools/call SSE stream to trigger client reconnection
2025-11-24T16:15:14.541Z [incoming-request             ] INFO    Received GET request for / (Last-Event-ID: event-2)
2025-11-24T16:15:14.541Z [outgoing-sse-event           ] INFO    Sent SSE priming event on GET stream (id: event-3, retry: 500ms)
2025-11-24T16:15:14.541Z [outgoing-sse-event           ] INFO    Sent tool response on GET stream after reconnection (id: event-4)
2025-11-24T16:15:14.563Z [client-sse-graceful-reconnect] SUCCESS Client reconnects via GET after SSE stream is closed gracefully
2025-11-24T16:15:14.563Z [client-sse-retry-timing      ] SUCCESS Client MUST respect the retry field, waiting the given number of milliseconds before attempting to reconnect
2025-11-24T16:15:14.563Z [client-sse-last-event-id     ] SUCCESS Client SHOULD send Last-Event-ID header on reconnection for resumability

Test Results:
Passed: 3/3, 0 failed, 0 warnings

[pkg-pr-new]

Open in StackBlitz

npx https://pkg.pr.new/modelcontextprotocol/conformance/@modelcontextprotocol/conformance@52

commit: c385462