Files
n8n-mcp/tests/integration/mcp-protocol
Romuald Członkowski 9590f751d2 fix: resolve multiple n8n_update_partial_workflow bugs (#635)
* fix: use correct MCP SDK API for server capabilities in test

getServerVersion() returns Implementation (name/version only), not the
full init result. Use client.getServerCapabilities() instead to access
server capabilities, fixing the CI typecheck failure.

Concieved by Romuald Członkowski - www.aiadvisors.pl/en

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: resolve multiple n8n_update_partial_workflow bugs (#592, #599, #610, #623, #624, #625, #629, #630, #633)

Phase 1 - Data loss prevention:
- Add missing unary operators (empty, notEmpty, exists, notExists) to sanitizer (#592)
- Preserve positional empty arrays in connections during removeNode/cleanStale (#610)
- Scope sanitization to modified nodes only, preventing unrelated node corruption
- Add empty body {} to activate/deactivate POST calls to fix 415 errors (#633)

Phase 2 - Error handling & response clarity:
- Serialize Zod errors to readable "path: message" strings (#630)
- Add saved:true/false field to all response paths (#625)
- Improve updateNode error hint with correct structure example (#623)
- Track removed node names for better removeConnection errors (#624)

Phase 3 - Connection & type fixes:
- Coerce sourceOutput/targetInput to String() consistently (#629)
- Accept numeric sourceOutput/targetInput at Zod schema level via transform

Phase 4 - Tag operations via dedicated API (#599):
- Track tags as tagsToAdd/tagsToRemove instead of mutating workflow.tags
- Orchestrate tag creation and association via listTags/createTag/updateWorkflowTags
- Reconcile conflicting add/remove for same tag (last operation wins)
- Tag failures produce warnings, not hard errors

Conceived by Romuald Członkowski - www.aiadvisors.pl/en

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* docs: add v2.37.0 changelog entry

Conceived by Romuald Członkowski - www.aiadvisors.pl/en

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: resolve pre-existing integration test failures in CI

- Create new MCP Server instance per connection in test helpers (SDK 1.27+
  requires separate Protocol instance per connection)
- Normalize database paths with path.resolve() in shared-database singleton
  to prevent path mismatch errors across test files
- Add no-op catch handler to deferred initialization promise in server.ts
  to prevent unhandled rejection warnings
- Properly call mcpServer.shutdown() in test helper close() to release
  shared database references

Conceived by Romuald Członkowski - www.aiadvisors.pl/en

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-14 17:27:33 +01:00
..

MCP Protocol Integration Tests

This directory contains comprehensive integration tests for the Model Context Protocol (MCP) implementation in n8n-mcp.

Test Structure

Core Tests

  • basic-connection.test.ts - Tests basic MCP server functionality and tool execution
  • protocol-compliance.test.ts - Tests JSON-RPC 2.0 compliance and protocol specifications
  • tool-invocation.test.ts - Tests all MCP tool categories and their invocation
  • session-management.test.ts - Tests session lifecycle, multiple sessions, and recovery
  • error-handling.test.ts - Tests error handling, edge cases, and invalid inputs
  • performance.test.ts - Performance benchmarks and stress tests

Helper Files

  • test-helpers.ts - TestableN8NMCPServer wrapper for testing with custom transports

Running Tests

# Run all MCP protocol tests
npm test -- tests/integration/mcp-protocol/

# Run specific test file
npm test -- tests/integration/mcp-protocol/basic-connection.test.ts

# Run with coverage
npm test -- tests/integration/mcp-protocol/ --coverage

Test Coverage

These tests ensure:

  • JSON-RPC 2.0 protocol compliance
  • Proper request/response handling
  • All tool categories are tested
  • Error handling and edge cases
  • Session management and lifecycle
  • Performance and scalability

Known Issues

  1. The InMemoryTransport from MCP SDK has some limitations with connection lifecycle
  2. Tests use the actual database, so they require data/nodes.db to exist
  3. Some tests are currently skipped due to transport issues (being worked on)

Future Improvements

  1. Mock the database for true unit testing
  2. Add WebSocket transport tests
  3. Add authentication/authorization tests
  4. Add rate limiting tests
  5. Add more performance benchmarks