fix: handle EndOfStream and ClosedResourceError in send_request #1939
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Fixes modelcontextprotocol#1717 The `send_request` method only catches `TimeoutError` from the `response_stream_reader.receive()` call. If `receive()` raises `EndOfStream` or `ClosedResourceError` (e.g., when the connection closes unexpectedly), these exceptions propagate without being caught, potentially leaving `response_or_error` unassigned and causing an `UnboundLocalError` at the subsequent isinstance check. This adds explicit handling for these stream closure exceptions, converting them to `McpError` with `CONNECTION_CLOSED` error code. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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Summary
Fixes #1717
Adds handling for
EndOfStreamandClosedResourceErrorinsend_request(). These exceptions can be raised byresponse_stream_reader.receive()but weren't being caught, leading toUnboundLocalErrorat the subsequentisinstancecheck.Changes
except (anyio.EndOfStream, anyio.ClosedResourceError)block after the existingTimeoutErrorhandlerMcpErrorwithCONNECTION_CLOSEDerror codeValidation
uv run pyrightpasses with 0 errorsTesting
Closes #1717