Commit Graph

1 Commits

Author SHA1 Message Date
czlonkowski
aeb74102e5 fix: preserve array indices in multi-output nodes when removing connections
CRITICAL BUG FIX: Fixed array index corruption in multi-output nodes
(Switch, IF with multiple handlers, Merge) when rewiring connections.

Problem:
- applyRemoveConnection() filtered out empty arrays after removing connections
- This caused indices to shift in multi-output nodes
- Example: Switch.main = [[H0], [H1], [H2]] -> remove H1 -> [[H0], [H2]]
- H2 moved from index 2 to index 1, corrupting workflow structure

Root Cause:
```typescript
// Line 697 - BUGGY CODE:
workflow.connections[node][output] =
  connections.filter(conns => conns.length > 0);
```

Solution:
- Only remove trailing empty arrays
- Preserve intermediate empty arrays to maintain index integrity
- Example: [[H0], [], [H2]] stays [[H0], [], [H2]] not [[H0], [H2]]

Impact:
- Prevents production-breaking workflow corruption
- Fixes rewireConnection operation for multi-output nodes
- Critical for AI agents working with complex workflows

Testing:
- Added integration test for Switch node rewiring with array index verification
- Test creates 4-output Switch node, rewires middle connection
- Verifies indices 0, 2, 3 unchanged after rewiring index 1
- All 137 unit tests + 12 integration tests passing

Discovered by: @agent-n8n-mcp-tester during comprehensive testing
Issue: #272 (Connection Operations - Phase 1)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
2025-10-06 09:18:27 +02:00