Professional API testing framework using Postman collections and Newman CLI automation for the JSONPlaceholder REST API.

This project demonstrates:

• ✅ Professional API testing with Postman
• ✅ Multi-environment testing (Dev, QA, Staging)
• ✅ CLI automation with Newman
• ✅ HTML reporting with newman-reporter-htmlextra
• ✅ Organized test suites with clear structure
• ✅ CI/CD ready architecture

This is NOT just running Postman tests.
This IS a complete testing framework for API validation.

postman-newman-api-testing/
├── collections/
│   └── JSONPlaceholder_API_Tests.postman_collection.json
├── environments/
│   ├── JSONPlaceholder-Dev.postman_environment.json
│   ├── JSONPlaceholder-QA.postman_environment.json
│   └── JSONPlaceholder-Staging.postman_environment.json
├── reports/                        # Generated HTML reports
├── docs/                           # Documentation
├── .gitignore
├── package.json
└── README.md

Positive Tests:

• ✅ Get all posts
• ✅ Get single post by ID
• ✅ Create new post
• ✅ Update existing post
• ✅ Delete post
• ✅ Response time validation (< 2000ms)

Negative Tests:

• ❌ 404 - Post not found
• ❌ Missing required fields
• ❌ Invalid data handling

• Node.js v14+
• Postman (for GUI testing)
• Newman CLI (installed via npm)

1. Clone the repository:

   git clone https://github.com/your-username/postman-newman-api-testing.git
   cd postman-newman-api-testing

2. Install dependencies:

   npm install

3. Verify installation:

   npx newman --version
   # Should show: newman/6.x.x

The project uses cross-platform NPM scripts to run the tests.

npm run test:dev
npm run test:qa
npm run test:staging

This will run the full test suite in the specified environment and automatically generate an HTML report in the reports/ folder.

npm run test:all

npm run test:smoke

Runs only the GET Operations folder for quick validation.

Basic run:

npx newman run collections/JSONPlaceholder_API_Tests.postman_collection.json \
  -e environments/JSONPlaceholder-Dev.postman_environment.json

• Base URL: https://jsonplaceholder.typicode.com
• Purpose: Local development testing
• Variables: base_url, post_id, environment

• Base URL: https://jsonplaceholder.typicode.com
• Purpose: QA environment validation
• Variables: base_url, post_id, environment

• Base URL: https://jsonplaceholder.typicode.com
• Purpose: Pre-production testing
• Variables: base_url, post_id, environment, timeout

Note: In a real project, each environment would have different URLs.

┌─────────────────────────┬───────────────────┬───────────────────┐
│                         │          executed │            failed │
├─────────────────────────┼───────────────────┼───────────────────┤
│              iterations │                 1 │                 0 │
├─────────────────────────┼───────────────────┼───────────────────┤
│                requests │                 8 │                 0 │
├─────────────────────────┼───────────────────┼───────────────────┤
│              assertions │                32 │                 0 │
└─────────────────────────┴───────────────────┴───────────────────┘

Open reports/[env]-report-[timestamp].html in browser for:

• ✅ Visual test results dashboard
• ✅ Request/response details
• ✅ Execution timeline
• ✅ Performance metrics
• ✅ Pass/fail statistics

Tests are organized in numbered folders for sequential execution:

1. POST - GET/
   ├── Get all Requests       # Lists all posts
   └── Get Single Post        # Retrieves post by ID

2. Posts - POST/
   └── Create New Post        # Creates a new post

3. Posts - PUT/PATCH/
   └── Update Post (PUT)      # Updates existing post

4. Posts - DELETE/
   └── Delete Post            # Deletes a post

5. Negative Tests/
   ├── Get Post - Not Found   # 404 handling
   ├── Create Post - Missing Body  # Validation
   └── Delete Post - Not Found     # Error handling

pm.test("Status code is 200", function () {
  pm.response.to.have.status(200);
});

pm.test("Response time is less than 2000ms", function () {
  pm.expect(pm.response.responseTime).to.be.below(2000);
});

pm.test("Response is an array", function () {
  const jsonData = pm.response.json();
  pm.expect(jsonData).to.be.an("array");
});

pm.test("Post has correct structure", function () {
  const post = pm.response.json()[0];
  pm.expect(post).to.have.property("userId");
  pm.expect(post).to.have.property("id");
  pm.expect(post).to.have.property("title");
  pm.expect(post).to.have.property("body");
});

API Testing:

• RESTful API validation
• HTTP methods (GET, POST, PUT, DELETE)
• Status code verification
• Response validation
• Error handling

Automation:

• Newman CLI usage
• Environment management
• Batch scripting
• Report generation

Quality Assurance:

• Test organization
• Positive/negative testing
• Regression testing
• Multi-environment validation

1. Open collection in Postman
2. Add new request to appropriate folder
3. Write test scripts in "Tests" tab
4. Export collection (v2.1)
5. Replace collections/JSONPlaceholder_API_Tests.postman_collection.json

1. Create environment in Postman
2. Add required variables (base_url, etc.)
3. Export environment
4. Save to environments/ folder
5. Update scripts to include new environment

• Postman Learning Center
• Newman Documentation
• newman-reporter-htmlextra
• JSONPlaceholder API

• Add data-driven testing with CSV/JSON
• Implement CI/CD with GitHub Actions
• Add performance testing scenarios
• Create custom Newman reporter
• Add authentication testing (OAuth, JWT)
• Integrate with test management tools

• GitHub: https://github.com/ChandeDeVargas
• LinkedIn: https://www.linkedin.com/in/chande-de-vargas-b8a51838a/

This project is open source and available under the MIT License.

⭐ If this project helped you learn Postman and Newman, give it a star!