Track hasReceivedMessageDelta and hasReceivedMessageStop in both
streaming paths (pipe-through and SSE-processing). Conditionally
omit these events from buildSyntheticErrorResponse() when upstream
already sent them, preventing protocol violations.
Closes#491
* fix(cliproxy): guard against empty upstream SSE responses in agy profile
When CLIProxyAPIPlus drops unsigned thinking blocks during sub-agent
execution, the response stream can contain no content_block_start or
message_delta events. This causes Claude Code CLI to crash with
"No assistant message found".
Add empty response detection in the tool sanitization proxy's streaming
handler. Both the pipe-through and SSE-processing paths now track
whether meaningful content was received. If upstream sent data but no
content blocks on a 200 OK, a synthetic minimal valid SSE response is
injected to prevent the client crash and surface a clear error message.
Closes#350
* fix(cliproxy): improve empty response detection and add tests
Address code review findings:
- Remove message_delta from content detection (lifecycle event, not
content); only content_block_start indicates actual content
- Add try-catch in end handlers to handle client disconnects gracefully
- Add 3 integration tests: empty stream injection, normal stream
passthrough, 4xx/5xx non-injection
* fix(cliproxy): avoid duplicate message_start in synthetic response
Track whether upstream already sent a message_start event. When
injecting the synthetic error response, omit message_start if upstream
already sent one, preventing duplicate events in the SSE stream.
Addresses PR review feedback from ccs-reviewer[bot].
* test(cliproxy): add SSE processing path and real failure mode tests
Address code review observations:
- Add test exercising SSE processing path (sanitized tool names) for
empty response detection, ensuring both code paths are covered
- Add test mirroring real failure mode where upstream sends only
message_start then ends abruptly (no message_delta/message_stop)
- Document duplicate message_start assumption with inline comment
- Test proxy lifecycle (start/stop)
- Test request sanitization (duplicates, truncation, passthrough)
- Test response restoration (buffered and SSE streaming)
- Test error handling (invalid JSON, upstream errors)
- Test multiple tools with mapping tracking
- Mock upstream server for isolated testing
