n8n-mcp/tests/unit/__mocks__/README.md

n8n-nodes-base Mock

This directory contains comprehensive mocks for n8n packages used in unit tests.

n8n-nodes-base Mock

The n8n-nodes-base.ts mock provides a complete testing infrastructure for code that depends on n8n nodes.

Features

1. Pre-configured Node Types

   • webhook - Trigger node with webhook functionality
   • httpRequest - HTTP request node with mock responses
   • slack - Slack integration with all resources and operations
   • function - JavaScript code execution node
   • noOp - Pass-through utility node
   • merge - Data stream merging node
   • if - Conditional branching node
   • switch - Multi-output routing node

2. Flexible Mock Behavior

   • Override node execution logic
   • Customize node descriptions
   • Add custom nodes dynamically
   • Reset all mocks between tests

Basic Usage

import { vi } from 'vitest';

// Mock the module
vi.mock('n8n-nodes-base', () => import('../__mocks__/n8n-nodes-base'));

// In your test
import { getNodeTypes, mockNodeBehavior, resetAllMocks } from '../__mocks__/n8n-nodes-base';

describe('Your test', () => {
  beforeEach(() => {
    resetAllMocks();
  });

  it('should get node description', () => {
    const registry = getNodeTypes();
    const slackNode = registry.getByName('slack');
    
    expect(slackNode?.description.name).toBe('slack');
  });
});

Advanced Usage

Override Node Behavior

mockNodeBehavior('httpRequest', {
  execute: async function(this: IExecuteFunctions) {
    return [[{ json: { custom: 'response' } }]];
  }
});

Add Custom Nodes

import { registerMockNode } from '../__mocks__/n8n-nodes-base';

const customNode = {
  description: {
    displayName: 'Custom Node',
    name: 'customNode',
    group: ['transform'],
    version: 1,
    description: 'A custom test node',
    defaults: { name: 'Custom' },
    inputs: ['main'],
    outputs: ['main'],
    properties: []
  },
  execute: async function() {
    return [[{ json: { result: 'custom' } }]];
  }
};

registerMockNode('customNode', customNode);

Mock Execution Context

const mockContext = {
  getInputData: vi.fn(() => [{ json: { test: 'data' } }]),
  getNodeParameter: vi.fn((name: string) => {
    const params = {
      method: 'POST',
      url: 'https://api.example.com'
    };
    return params[name];
  }),
  getCredentials: vi.fn(async () => ({ apiKey: 'test-key' })),
  helpers: {
    returnJsonArray: vi.fn(),
    httpRequest: vi.fn()
  }
};

const result = await node.execute.call(mockContext);

Mock Structure

Each mock node implements the INodeType interface with:

• description: Complete node metadata including properties, inputs/outputs, credentials
• execute: Mock implementation for regular nodes (returns INodeExecutionData[][])
• webhook: Mock implementation for trigger nodes (returns webhook data)

Testing Patterns

1. Unit Testing Node Logic

   const node = registry.getByName('slack');
   const result = await node.execute.call(mockContext);
   expect(result[0][0].json.ok).toBe(true);
   

2. Testing Node Properties

   const node = registry.getByName('httpRequest');
   const methodProp = node.description.properties.find(p => p.name === 'method');
   expect(methodProp.options).toHaveLength(6);
   

3. Testing Conditional Nodes

   const ifNode = registry.getByName('if');
   const [trueOutput, falseOutput] = await ifNode.execute.call(mockContext);
   expect(trueOutput).toHaveLength(2);
   expect(falseOutput).toHaveLength(1);
   

Utilities

• resetAllMocks() - Clear all mock function calls
• mockNodeBehavior(name, overrides) - Override specific node behavior
• registerMockNode(name, node) - Add new mock nodes
• getNodeTypes() - Get the node registry with getByName and getByNameAndVersion

See Also

• tests/unit/examples/using-n8n-nodes-base-mock.test.ts - Complete usage examples
• tests/unit/__mocks__/n8n-nodes-base.test.ts - Mock test coverage