fix(mcp): retry list roots request over streamable http#41490
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The MCP SDK delivers server-initiated requests (like listRoots) only over the client's standalone SSE channel, which the client opens lazily after sending the `initialized` notification. When the first tool call races ahead of that, the server has no stream to send listRoots on and the SDK silently drops it, so the client never receives the request. Use a short timeout and retry once, by which point the SSE channel is established. This fixes frequent flaking of the `client should receive list roots request` test on CI.
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Test results for "MCP"7409 passed, 1132 skipped Merge workflow run. |
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Restores #37324, which was removed in #37399. This still happens on the bots, see the flaky test
tests/mcp/http.spec.ts:349 > client should receive list roots request.Fixes a race: the MCP SDK delivers
listRootsonly over the client's standalone SSE channel, which the client opens lazily after sendinginitialized. If the first tool call reaches the server'slistRoots()before that channel registers, the SDK silently drops the request and the client never receives it.