Load Tester for API using Node.js and TypeScript

A high-performance, lightweight API load testing tool built with Node.js and TypeScript. Stress-test GET and POST endpoints with configurable RPS and duration, featuring detailed logging and recursive data generation.

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🚀 Key Features

• Asynchronous Execution: Leverages Node.js event loop and axios for efficient concurrent request handling.
• Configurable Load: Easily set requestsPerSecond and durationInSeconds for tailored stress testing.
• Detailed Logging: All failed requests and (optionally) successful ones are logged to the results/ directory with timing and response bodies.
• Robust Request Tracking: Ensures accurate reporting of sent vs. completed requests, even under heavy failure rates.
• Type-Safe Dynamic Data: Uses a recursive data generator for complex POST request payloads.
• Modern Stack: Developed with TypeScript 5+, ESM, and strict linting rules.

🛠️ Prerequisites

• Node.js: v18.0.0 or higher
• npm: v9.0.0 or higher

📦 Installation & Setup

1. Clone the Repository:

   git clone https://github.com/Alike73/API-TESTER.git
   cd api-tester

2. Install Dependencies: Ensure you have Node.js installed, then run:

   npm install

3. Configure Environment: Create a .env file in the root directory:

   BASE_URL=https://api.example.com/endpoint
   TOKEN=your_bearer_token_here

🏃 Usage

You can execute the tests directly using tsx (no pre-compilation required):

GET Test

Used for performance testing read endpoints with optional query parameters.

npx tsx testGet.ts

POST Test

Used for stress testing write endpoints with dynamic payload generation.

npx tsx testPost.ts

📊 Results

Test summaries and failure logs are saved in the results/ directory:

• results/results.txt: Output from GET tests.
• results/post_results.txt: Output from POST tests.

🏗️ Architecture & Best Practices

Code Quality

• TypeScript: Strict type checking enforced (noImplicitAny: true, etc.).
• ESLint: Configured with typescript-eslint for consistent code quality.
• Error Handling: Uses axios.isAxiosError type guards for precise error reporting.

Performance Testing Strategy (QA Best Practices)

1. RPS Throttling: Uses setInterval with internal loops to maintain a steady request rate.
2. Graceful Completion: Uses finally blocks to track request completion, ensuring final reports are only generated after all pending requests are settled.
3. Log Management: Separates results by test type and prevents log bloat by allowing optional logging of successful responses.

🧹 Maintenance

Type Checking:

npx tsc --noEmit

Linting:

npx eslint .

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Senior QA & TypeScript Recommendation: Always verify your .env configuration against a staging environment before running high RPS tests to avoid unintentional API rate limiting or service disruption.