n8n Workflow Testing Fundamentals

<default_to_action> When testing n8n workflows:

1. VALIDATE workflow structure before execution
2. TEST with realistic test data
3. VERIFY node-to-node data flow
4. CHECK error handling paths
5. MEASURE execution performance

Quick n8n Testing Checklist:

• All nodes properly connected (no orphans)
• Trigger node correctly configured
• Data mappings between nodes valid
• Error workflows defined
• Credentials properly referenced

Critical Success Factors:

• Test each execution path separately
• Validate data transformations at each node
• Check retry and error handling behavior
• Verify integrations with external services </default_to_action>

Quick Reference Card

When to Use

• Testing new n8n workflows
• Validating workflow changes
• Debugging failed executions
• Performance optimization
• Pre-deployment validation

n8n Workflow Components

Component	Purpose	Testing Focus
Trigger	Starts workflow	Reliable activation, payload handling
Action Nodes	Process data	Configuration, data mapping
Logic Nodes	Control flow	Conditional routing, branches
Integration Nodes	External APIs	Auth, rate limits, errors
Error Workflow	Handle failures	Recovery, notifications

Workflow Execution States

State	Meaning	Test Action
running	Currently executing	Monitor progress
success	Completed successfully	Validate outputs
failed	Execution failed	Analyze error
waiting	Waiting for trigger	Test trigger mechanism

---

Workflow Structure Validation

// Validate workflow structure before execution
async function validateWorkflowStructure(workflowId: string) {
  const workflow = await getWorkflow(workflowId);

  // Check for trigger node
  const triggerNode = workflow.nodes.find(n =>
    n.type.includes('trigger') || n.type.includes('webhook')
  );
  if (!triggerNode) {
    throw new Error('Workflow must have a trigger node');
  }

  // Check for orphan nodes (no connections)
  const connectedNodes = new Set();
  for (const [source, targets] of Object.entries(workflow.connections)) {
    connectedNodes.add(source);
    for (const outputs of Object.values(targets)) {
      for (const connections of outputs) {
        for (const conn of connections) {
          connectedNodes.add(conn.node);
        }
      }
    }
  }

  const orphans = workflow.nodes.filter(n => !connectedNodes.has(n.name));
  if (orphans.length > 0) {
    console.warn('Orphan nodes detected:', orphans.map(n => n.name));
  }

  // Validate credentials
  for (const node of workflow.nodes) {
    if (node.credentials) {
      for (const [type, ref] of Object.entries(node.credentials)) {
        if (!await credentialExists(ref.id)) {
          throw new Error(`Missing credential: ${type} for node ${node.name}`);
        }
      }
    }
  }

  return { valid: true, orphans, triggerNode };
}

---

Execution Testing

// Test workflow execution with various inputs
async function testWorkflowExecution(workflowId: string, testCases: TestCase[]) {
  const results: TestResult[] = [];

  for (const testCase of testCases) {
    const startTime = Date.now();

    // Execute workflow
    const execution = await executeWorkflow(workflowId, testCase.input);

    // Wait for completion
    const result = await waitForCompletion(execution.id, testCase.timeout || 30000);

    // Validate output
    const outputValid = validateOutput(result.data, testCase.expected);

    results.push({
      testCase: testCase.name,
      success: result.status === 'success' && outputValid,
      duration: Date.now() - startTime,
      actualOutput: result.data,
      expectedOutput: testCase.expected
    });
  }

  return results;
}

// Example test cases
const testCases = [
  {
    name: 'Valid customer data',
    input: { name: 'John Doe', email: '[email protected]' },
    expected: { processed: true, customerId: /^cust_/ },
    timeout: 10000
  },
  {
    name: 'Missing email',
    input: { name: 'Jane Doe' },
    expected: { error: 'Email required' },
    timeout: 5000
  },
  {
    name: 'Invalid email format',
    input: { name: 'Bob', email: 'not-an-email' },
    expected: { error: 'Invalid email' },
    timeout: 5000
  }
];

---

Data Flow Validation

// Trace data through workflow nodes
async function validateDataFlow(executionId: string) {
  const execution = await getExecution(executionId);
  const nodeResults = execution.data.resultData.runData;

  const dataFlow: DataFlowStep[] = [];

  for (const [nodeName, runs] of Object.entries(nodeResults)) {
    for (const run of runs) {
      dataFlow.push({
        node: nodeName,
        input: run.data?.main?.[0]?.[0]?.json || {},
        output: run.data?.main?.[0]?.[0]?.json || {},
        executionTime: run.executionTime,
        status: run.executionStatus
      });
    }
  }

  // Validate data transformations
  for (let i = 1; i < dataFlow.length; i++) {
    const prev = dataFlow[i - 1];
    const curr = dataFlow[i];

    // Check if expected data passed through
    validateDataMapping(prev.output, curr.input);
  }

  return dataFlow;
}

// Validate data mapping between nodes
function validateDataMapping(sourceOutput: any, targetInput: any) {
  // Check all required fields are present
  const missingFields: string[] = [];

  for (const [key, value] of Object.entries(targetInput)) {
    if (value === undefined && sourceOutput[key] === undefined) {
      missingFields.push(key);
    }
  }

  if (missingFields.length > 0) {
    console.warn('Missing fields in data mapping:', missingFields);
  }

  return missingFields.length === 0;
}

---

Error Handling Testing

// Test error handling paths
async function testErrorHandling(workflowId: string) {
  const errorScenarios = [
    {
      name: 'API timeout',
      inject: { delay: 35000 }, // Trigger timeout
      expectedError: 'timeout'
    },
    {
      name: 'Invalid data',
      inject: { invalidField: true },
      expectedError: 'validation'
    },
    {
      name: 'Missing credentials',
      inject: { removeCredentials: true },
      expectedError: 'authentication'
    }
  ];

  const results: ErrorTestResult[] = [];

  for (const scenario of errorScenarios) {
    // Execute with error injection
    const execution = await executeWithErrorInjection(workflowId, scenario.inject);

    // Check error was caught
    const result = await waitForCompletion(execution.id);

    // Validate error handling
    results.push({
      scenario: scenario.name,
      errorCaught: result.status === 'failed',
      errorType: result.data?.resultData?.error?.type,
      expectedError: scenario.expectedError,
      errorWorkflowTriggered: await checkErrorWorkflowTriggered(execution.id),
      alertSent: await checkAlertSent(execution.id)
    });
  }

  return results;
}

// Verify error workflow was triggered
async function checkErrorWorkflowTriggered(executionId: string): Promise<boolean> {
  const errorExecutions = await getExecutions({
    filter: {
      metadata: { errorTriggeredBy: executionId }
    }
  });

  return errorExecutions.length > 0;
}

---

Node Connection Patterns

Linear Flow

Trigger → Process → Transform → Output

Testing: Execute once, validate each node output

Branching Flow

Trigger → IF → [Branch A] → Merge → Output
              → [Branch B] →

Testing: Test both branches separately, verify merge behavior

Parallel Flow

Trigger → Split → [Process A] → Merge → Output
                → [Process B] →

Testing: Validate parallel execution, check merge timing

Loop Flow

Trigger → SplitInBatches → Process → [Loop back until done] → Output

Testing: Test with varying batch sizes, verify all items processed

---

Common Testing Patterns

Test Data Generation

// Generate test data for common n8n patterns
const testDataGenerators = {
  webhook: () => ({
    body: { event: 'test', timestamp: new Date().toISOString() },
    headers: { 'Content-Type': 'application/json' },
    query: { source: 'test' }
  }),

  slack: () => ({
    type: 'message',
    channel: 'C123456',
    user: 'U789012',
    text: 'Test message'
  }),

  github: () => ({
    action: 'opened',
    issue: {
      number: 1,
      title: 'Test Issue',
      body: 'Test body'
    },
    repository: {
      full_name: 'test/repo'
    }
  }),

  stripe: () => ({
    type: 'payment_intent.succeeded',
    data: {
      object: {
        id: 'pi_test123',
        amount: 1000,
        currency: 'usd'
      }
    }
  })
};

Execution Assertions

// Common assertions for workflow execution
const workflowAssertions = {
  // Assert workflow completed
  assertCompleted: (execution) => {
    expect(execution.finished).toBe(true);
    expect(execution.status).toBe('success');
  },

  // Assert specific node executed
  assertNodeExecuted: (execution, nodeName) => {
    const nodeData = execution.data.resultData.runData[nodeName];
    expect(nodeData).toBeDefined();
    expect(nodeData[0].executionStatus).toBe('success');
  },

  // Assert data transformation
  assertDataTransformed: (execution, nodeName, expectedData) => {
    const nodeOutput = execution.data.resultData.runData[nodeName][0].data.main[0][0].json;
    expect(nodeOutput).toMatchObject(expectedData);
  },

  // Assert execution time
  assertExecutionTime: (execution, maxMs) => {
    const duration = new Date(execution.stoppedAt) - new Date(execution.startedAt);
    expect(duration).toBeLessThan(maxMs);
  }
};

---

Agent Coordination Hints

Memory Namespace

aqe/n8n/
├── workflows/*          - Cached workflow definitions
├── test-results/*       - Test execution results
├── validations/*        - Validation reports
├── patterns/*           - Discovered testing patterns
└── executions/*         - Execution tracking

Fleet Coordination

// Comprehensive n8n testing with fleet
const n8nFleet = await FleetManager.coordinate({
  strategy: 'n8n-testing',
  agents: [
    'n8n-workflow-executor',  // Execute and validate
    'n8n-node-validator',     // Validate configurations
    'n8n-trigger-test',       // Test triggers
    'n8n-expression-validator', // Validate expressions
    'n8n-integration-test'    // Test integrations
  ],
  topology: 'parallel'
});

---

Related Skills

• n8n-expression-testing - Expression validation
• n8n-trigger-testing-strategies - Trigger testing
• n8n-integration-testing-patterns - Integration testing
• n8n-security-testing - Security validation

---

Remember

n8n workflows are JSON-based execution flows that connect 400+ services. Testing requires validating:

• Workflow structure (nodes, connections)
• Trigger reliability (webhooks, schedules)
• Data flow (transformations between nodes)
• Error handling (retry, fallback, notifications)
• Performance (execution time, resource usage)

With Agents: Use n8n-workflow-executor for execution testing, n8n-node-validator for configuration validation, and coordinate multiple agents for comprehensive workflow testing.