chore(core): simplify connection handling & fix graceful reconnect

[NathanFlurry]

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Project	Deployment	Preview	Comments	Updated (UTC)
rivetkit-serverless	Error			Sep 26, 2025 3:35am

[claude]

Claude finished @NathanFlurry's task —— View job

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Code Review Complete ✅

Reviewing PR #1309: "chore(core): simplify connection handling & fix graceful reconnect"

Todo List:

• Read repository guidelines (CLAUDE.md)
• Examine the new conn-drivers.ts implementation
• Review connection handling changes in instance.ts
• Analyze deleted files and their impact
• Check router-endpoints.ts modifications
• Assess test coverage impact
• Provide comprehensive review feedback

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🚨 Critical Issues

Bug: Incorrect Driver Return in conn-drivers.ts

Location: packages/rivetkit/src/actor/conn-drivers.ts:203

// 🚨 BUG: HTTP connections will return SSE_DRIVER instead of HTTP_DRIVER
else if (ConnDriverKind.HTTP in state) return SSE_DRIVER;  // Should be HTTP_DRIVER

Impact: HTTP connections will fail with incorrect driver behavior, potentially causing runtime errors or unexpected connection handling.

Fix:

else if (ConnDriverKind.HTTP in state) return HTTP_DRIVER;

TODO Comments Need Resolution

Location: packages/rivetkit/src/actor/conn-drivers.ts:182-188

// TODO: This might not be the correct logic
getConnectionReadyState(_actor, _conn) {
    return ConnReadyState.OPEN;
},
disconnect: async () => {
    // Noop
    // TODO: Abort the request
},

Concern: HTTP driver implementation is incomplete with acknowledged uncertainty about correctness.

---

⚠️ Code Quality Issues

1. WebSocket Buffer Handling Complexity

Location: packages/rivetkit/src/actor/conn-drivers.ts:92-119

The WebSocket message sending logic has complex buffer handling that could be simplified:

• Multiple branching paths for different buffer types
• SharedArrayBuffer conversion logic
• Extensive logging that clutters the core logic

Suggestion: Consider extracting buffer conversion to a separate utility function for better testability.

2. Connection Liveness Removed from Tests

Impact: The deletion of conn-liveness.ts test fixture removes important test coverage for connection management, particularly:

• Connection timeout handling
• Dead connection cleanup
• Reconnection scenarios

Recommendation: Ensure equivalent test coverage exists elsewhere or add new tests for the refactored connection handling.

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✅ Positive Changes

1. Improved Architecture

• Clean separation of connection driver concerns
• Driver pattern allows for better extensibility
• Simplified connection state management

2. Graceful WebSocket Disconnect

The WebSocket driver properly implements graceful disconnection:

disconnect: async (/*...*/, state: ConnDriverWebSocketState, reason?: string) => {
    state.websocket.close(1000, reason);
    await state.closePromise.promise; // Wait for graceful close
}

3. Code Reduction

Significant reduction in lines of code (-675, +346) while maintaining functionality suggests good refactoring.

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🔍 Security Considerations

No security issues identified. The refactoring maintains proper connection authentication and doesn't introduce new attack vectors.

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🚀 Performance Considerations

Positive:

• Connection status checking is now centralized and more efficient
• Reduced code complexity should improve maintainability

Potential Concern:

• The connection liveness checking interval moved from driver-specific to actor-level (instance.ts:1118-1149)
• Ensure this doesn't create performance bottlenecks with many connections

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📋 Test Coverage Assessment

Lost Coverage:

• Connection liveness testing (deleted conn-liveness.ts)
• Generic connection driver testing (deleted generic-conn-driver.ts)

Maintained Coverage:

• Core connection tests in actor-conn.ts appear intact
• WebSocket, SSE, and HTTP connection paths still tested

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🔧 Recommendations

High Priority (Must Fix):

1. Fix the HTTP driver bug in getConnDriverFromState()
2. Resolve TODO comments in HTTP driver
3. Add test coverage for the new connection driver architecture

Medium Priority:

1. Simplify WebSocket buffer handling logic
2. Add JSDoc documentation for the new driver interfaces
3. Consider adding connection driver integration tests

Low Priority:

1. Extract buffer conversion utilities
2. Review logging verbosity in production

---

✨ Summary

This is a well-architected refactoring that improves code organization and implements graceful reconnection. However, there's a critical bug that must be fixed before merging. The overall direction is positive, making the connection handling more maintainable and extensible.

Recommendation: Fix the HTTP driver bug and address TODO comments before merging.

---

[NathanFlurry]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• chore(core): reimpl reconnect logic #1310
• fix(core): fix getters on ActorConn proxy #1311
• chore(core): simplify connection handling & fix graceful reconnect #1309 👈 (View in Graphite)
• chore(core): clean up token configs #1298
• fix(core): clean up websocket protocol handling #1297
• chore(core): add token & optional headers to client #1296
• feat: serverless #1288
• 09-16-fix_next-js_fix_example_for_next-js #1250
• fix(core): fix missing ManagerDriver impls #1308
• main

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Merge activity

• Sep 26, 7:06 AM UTC: NathanFlurry added this pull request to the Graphite merge queue.
• Sep 26, 7:06 AM UTC: CI is running for this pull request on a draft pull request (#1312) due to your merge queue CI optimization settings.
• Sep 26, 7:07 AM UTC: Merged by the Graphite merge queue via draft PR: #1312.