fix: Improve how websockets deal with timeouts and closed connections

[sanbotto]

Summary by CodeRabbit

• Bug Fixes
  • WebSocket close-handshake now forwards close frames correctly, enabling more graceful shutdowns
  • Certain close codes are normalized to avoid treating expected closures as failures
  • Abnormal connection closures are logged distinctly to surface unexpected terminations
  • Coordinated connection teardown reduces resource leaks during concurrent proxying operations

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 22db0619-5279-4aad-8ccf-4c79278fbb46

📥 Commits

Reviewing files that changed from the base of the PR and between 8f08888 and abcb20b.

📒 Files selected for processing (1)

• internal/server/server.go

🚧 Files skipped from review as they are similar to previous changes (1)

• internal/server/server.go

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Walkthrough

The pull request refines WebSocket proxying behavior in the server by improving close-handshake handling and goroutine coordination. proxyWebSocketCopy now detects close errors from the source connection and forwards the corresponding close frame to the destination instead of only returning the error. The handler synchronization in defaultProxyWebSocket was restructured to wait for one direction to complete, immediately close both connections to unblock the other goroutine, then await the second direction—replacing the previous deferred cleanup pattern. Abnormal closures are now distinguished in logging from expected normal closures.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: improving WebSocket handling for timeouts and closed connections through proper close handshake forwarding and refined connection teardown logic.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

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🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/improve-ws-timeouts

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@internal/server/server.go`:
- Around line 1190-1198: The loop that reads from src (calling
src.ReadMessage()) wrongly forwards websocket.CloseError codes 1005/1006/1015
directly to dst via websocket.FormatCloseMessage, which can send forbidden close
codes; update the error handling in that loop to detect a *websocket.CloseError,
map any CloseNoStatusReceived (1005), CloseAbnormalClosure (1006), or 1015 to a
safe code such as websocket.CloseGoingAway before calling
websocket.FormatCloseMessage and dst.WriteMessage, and then write the mapped
close frame (preserving the original Text if desired) so no reserved codes are
sent on the wire.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 3dba10c9-b47f-4049-b258-3247859759bd

📥 Commits

Reviewing files that changed from the base of the PR and between 57251dd and 8f08888.

📒 Files selected for processing (1)

• internal/server/server.go