fix: keep SSE alive past idle timeout (Safari "Connection lost")#376
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tomasz-tomczyk merged 1 commit intomainfrom Apr 28, 2026
Merged
fix: keep SSE alive past idle timeout (Safari "Connection lost")#376tomasz-tomczyk merged 1 commit intomainfrom
tomasz-tomczyk merged 1 commit intomainfrom
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Send an initial `:\n\n` SSE comment so EventSource fires onopen immediately (Safari delays this until the first body byte), and add a 30s heartbeat ticker so the stream isn't closed by the server's 60s IdleTimeout. Without the heartbeat, idle SSE connections hit the IdleTimeout and Safari surfaces repeated "Could not connect to the server" errors. Chromium and Firefox auto-reconnect more silently, which is why this looked Safari- specific even though the root cause affected all browsers. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #376 +/- ##
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+ Coverage 66.55% 66.59% +0.04%
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Files 19 19
Lines 8169 8176 +7
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+ Hits 5437 5445 +8
+ Misses 2310 2309 -1
Partials 422 422
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Summary
:\n\nSSE comment soEventSource.onopenfires immediately (Safari delays this until the first body byte).IdleTimeout.Why
Safari was surfacing repeated "Could not connect to the server" errors on the review page. Root cause was idle SSE connections hitting the server's
IdleTimeout: 60s— Chromium and Firefox auto-reconnect more silently, which is why this looked Safari-specific even though the root cause affected all browsers.Review
Test plan
TestEvents_SafariCompatasserts the initial:\n\nframe and heartbeat (withsseHeartbeatIntervalshrunk to 50ms).gofmt -l .cleangolangci-lint run ./...cleango test -race -count=1 ./...passes (46s)crit commentpropagated via SSE.🤖 Generated with Claude Code