Stress Testing DevTools Plugin

A comprehensive TanStack DevTools plugin that allows you to perform load testing on your APIs directly from the browser developer tools. Easily import requests from browser Network tabs, cURL commands, and other formats.

Features

🚀 Major improvements over the original bookmarklet:

• Professional UI: Clean, organized React-based interface integrated with TanStack DevTools
• Import from Network Tab: Copy requests directly from browser dev tools (cURL, fetch, PowerShell)
• Advanced Validation Engine: Comprehensive response validation with custom rules
• Visual Configuration Editor: No more manual JSON editing - visual forms with validation
• Test Single Requests: Test and examine responses before running stress tests
• Auto-Generate Validation Rules: AI-powered rule generation from response samples
• Better State Management: Centralized store with proper persistence
• Enhanced Metrics: More detailed performance metrics and error analysis
• Test History: Keep track of all your test runs with detailed comparisons
• Type Safety: Full TypeScript support with proper type definitions

📊 Core Features:

🔧 Request Management

• Import from Browser DevTools: Copy as cURL, fetch, PowerShell, or raw HTTP
• Visual Request Editor: Form-based configuration with validation
• Duplicate & Edit: Clone existing requests for quick variations
• Header & Body Management: JSON editing with syntax validation

🧪 Testing & Validation

• Test Single Requests: Execute and examine individual requests before stress testing
• Advanced Validation Rules: Multiple validation types (status, headers, body, performance)
• Auto-Generate Rules: Smart rule generation from response samples
• Custom Validation: JavaScript-based custom validation logic

⚡ Stress Testing

• Fixed Count Testing: Run specific number of requests with concurrency control
• Timed Rate Testing: Run tests for duration at controlled rate
• Real-time Metrics: Live updates of response times, success rates, and throughput
• Error Analysis: Detailed error categorization and reporting

🔐 Authentication & Tokens

• Automatic Token Handling: JWT and XSRF token extraction from browser
• Token Substitution: Dynamic replacement of {{tenantId}} and {{regionId}}
• Custom Headers: Support for any authentication method

Installation

npm install @sucoza/stress-testing-devtools-plugin

Quick Start Guide

1. 📥 Import a Request

The easiest way to get started is to import a request from your browser's Network tab:

1. Open your browser's Developer Tools
2. Go to the Network tab
3. Perform the API request you want to test
4. Right-click the request → Copy → Copy as cURL (or Copy as fetch)
5. In the plugin, click 📥 Import and paste your copied request
6. The plugin will automatically parse the request details

Supported formats:

• ✅ cURL commands (Chrome/Firefox DevTools)
• ✅ JavaScript fetch() (Chrome DevTools)
• ✅ PowerShell Invoke-RestMethod
• ✅ Raw HTTP requests

2. 🧪 Test Your Request

Before running a stress test, verify your request works:

1. Click 🧪 Test Request
2. Examine the response, headers, and timing
3. Click ✨ Generate Rules to create validation rules automatically
4. Customize the generated rules or add your own

3. ⚡ Run Stress Tests

Choose your testing approach:

Fixed Count Test:

• Set number of requests (e.g., 100)
• Set concurrency (e.g., 10 simultaneous requests)
• Click Run Fixed Test

Timed Rate Test:

• Set duration (e.g., 2 minutes)
• Set rate (e.g., 5 requests/second)
• Click Run Timed Test

4. 📊 Analyze Results

Monitor real-time metrics:

• Response times (avg, P50, P90, P95, P99)
• Success/failure rates
• Requests per second (RPS)
• Error breakdown by type

Usage

Basic Setup

import { createStressTestPlugin } from '@sucoza/stress-testing-devtools-plugin'

// Create the plugin with default configuration
const stressTestPlugin = createStressTestPlugin()

// Add to your TanStack DevTools configuration
import { TanStackDevtools } from '@tanstack/devtools'

const devtools = new TanStackDevtools({
  plugins: [stressTestPlugin]
})

Advanced Configuration

import { createStressTestPlugin } from '@sucoza/stress-testing-devtools-plugin'

const stressTestPlugin = createStressTestPlugin({
  initialConfigs: [
    {
      name: 'User Info',
      method: 'GET',
      path: '/api/users/me',
      inputParams: {},
      test: 'response.id !== undefined'
    },
    {
      name: 'Search Users',
      method: 'POST',
      path: '/api/users/search',
      inputParams: {
        tenantId: '{{tenantId}}',
        query: 'test'
      },
      test: 'response.users && response.users.length >= 0'
    }
  ]
})

Configuration Format

Each request configuration follows this structure:

interface StressTestConfig {
  name: string                              // Display name for the request
  method: 'GET' | 'POST' | 'PUT' | 'DELETE' | 'PATCH'
  path: string                              // API endpoint path
  inputParams: Record<string, any>          // Request body/parameters
  test: string                              // JavaScript expression to validate response
  headers?: Record<string, string>          // Optional additional headers
}

Test Validation

The test field should contain a JavaScript expression that evaluates to true for a successful response:

// Examples:
"response.length > 0"
"response.data !== undefined"
"response.users && response.users.length >= 0"
"response.success === true"

Token Substitution

Use these tokens in your inputParams and they will be automatically replaced:

• {{tenantId}} - Current user's tenant ID
• {{regionId}} - Current user's region ID

Example:

{
  "inputParams": {
    "tenantId": "{{tenantId}}",
    "regionId": "{{regionId}}"
  }
}

Advanced Validation Engine

The plugin includes a powerful validation engine that goes far beyond simple response checks:

Validation Rule Types

📊 Status Code Validation

// Check for successful status codes
{
  "type": "status",
  "operator": "equals",
  "expectedValue": 200
}

// Ensure not error codes
{
  "type": "status", 
  "operator": "lessThan",
  "expectedValue": 400
}

📋 Header Validation

// Check content type
{
  "type": "header",
  "target": "content-type",
  "operator": "contains", 
  "expectedValue": "application/json"
}

// Ensure security headers exist
{
  "type": "header",
  "target": "x-frame-options",
  "operator": "exists"
}

📄 Response Body Validation

// JSONPath validation
{
  "type": "body",
  "operator": "jsonPath",
  "target": "data.users[0].id",
  "expectedValue": 12345
}

// Content validation
{
  "type": "body", 
  "operator": "contains",
  "expectedValue": "success"
}

⏱️ Performance Validation

// Response time limits
{
  "type": "responseTime",
  "operator": "lessThan", 
  "expectedValue": 500
}

// Response size checks
{
  "type": "size",
  "operator": "greaterThan",
  "expectedValue": 100
}

⚙️ Custom Validation

Write custom JavaScript validation logic:

{
  "type": "custom",
  "operator": "custom",
  "customCode": `
    // Full access to response, status, headers, responseTime, responseSize
    if (response.data && Array.isArray(response.data.users)) {
      return response.data.users.length > 0;
    }
    return false;
  `
}

Auto-Generated Rules

The ✨ Generate Rules feature automatically creates validation rules based on your test response:

• ✅ Status code validation
• ✅ Content-Type header check
• ✅ Response structure validation
• ✅ Performance benchmarks
• ✅ Array length checks
• ✅ Success flag validation

These generated rules can be customized, enabled/disabled, or used as templates for more complex validation.

Metrics

The plugin provides comprehensive metrics for each test run:

• Total Requests: Number of requests executed
• Success Rate: Percentage of successful requests
• Response Times: Average, P50, P90, P95, P99, Min, Max
• Throughput: Current requests per second (RPS)
• Error Analysis: Breakdown of errors by type
• Duration: Total test execution time

Authentication

The plugin automatically handles authentication by:

1. JWT Tokens: Reads from localStorage.getItem('jwtToken')
2. XSRF Tokens: Extracts from cookies (XSRF-TOKEN-WEBAPI)
3. User Context: Fetches user info to populate {{tenantId}} and {{regionId}} tokens

Development

# Install dependencies
npm install

# Build the plugin
npm run build

# Development mode with watch
npm run dev

# Type checking
npm run type-check

Example

See the example/ directory for a complete working example of the plugin in action.

Comparison with Original Bookmarklet

License

MIT

Part of the @sucoza TanStack DevTools ecosystem.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.