Added 4 critical integration tests to prevent regression of the
production-breaking array index corruption bug in multi-output nodes.
Tests verify against real n8n API:
1. IF Node - Empty array preservation when removing connections
- Removes true branch connection
- Verifies empty array at index 0
- Verifies false branch stays at index 1 (not shifted)
2. Switch Node - Remove first case (MOST CRITICAL)
- Tests exact bug scenario that was production-breaking
- Removes case 0
- Verifies cases 1, 2, 3 stay at original indices
3. Switch Node - Sequential operations
- Complex scenario: rewire, add, remove in sequence
- Verifies indices maintained throughout operations
- Tests empty arrays preserved at intermediate positions
4. Filter Node - Rewiring connections
- Tests kept/discarded outputs (2-output node)
- Rewires one output
- Verifies other output unchanged
All tests validate actual workflow structure from n8n API to ensure
our fix (only remove trailing empty arrays) works correctly.
Coverage:
- Total: 174 tests (158 unit + 16 integration)
- All tests passing ✅
- Integration tests provide regression protection
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
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>
Created comprehensive integration tests that would have caught the bugs
that unit tests missed:
Bug 1: branch='true' mapping to sourceOutput instead of sourceIndex
Bug 2: Zod schema stripping branch and case parameters
Why unit tests missed these bugs:
- Unit tests checked in-memory workflow objects
- Expected wrong structure: workflow.connections.IF.true
- Should be: workflow.connections.IF.main[0] (real n8n structure)
Integration tests created (11 scenarios):
1. IF node with branch='true' - validates connection at IF.main[0]
2. IF node with branch='false' - validates connection at IF.main[1]
3. Both IF branches simultaneously - validates both coexist
4. Switch node with case parameter - validates correct indices
5. rewireConnection with branch parameter
6. rewireConnection with case parameter
7. Explicit sourceIndex overrides branch
8. Explicit sourceIndex overrides case
9. Invalid branch value - error handling
10. Negative case value - documents current behavior
11. Branch on non-IF node - validates graceful fallback
All 11 tests passing against real n8n API.
File: tests/integration/n8n-api/workflows/smart-parameters.test.ts (1,360 lines)
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
