API Data driven Testing (DDT)

Data-driven testing runs the same API request with multiple datasets to verify how the system behaves under different input conditions.

Step to Reproduce:

1. Create a Postman request for POST /products. For this example I will use https://api.escuelajs.co/api/v1/products
2. Replace request values with variables from the data file
3. Add Postman tests to validate:
   • status code
   • response body
4. Run the collection with the CSV/Excel data
5. Execute again with Newman for repeatable CLI testing
6. Newman Setup & Run
   💻 Install Newman:
   
   npm install -g newman
   
   💻 Run collection with data file:
   
   newman run <collection.json> -d <data.csv
   • Example
     
     newman run api-ddt.json -d data.csv

Data-Driven API Testing Workflow

DDT Execution in Postman

What This Demonstrates:

• Validation across multiple input combinations
• Consistent response verification
• Scalable API testing with reusable datasets
• Automation-ready execution with Newman

“Running one request is testing. Running many datasets is real QA.”