Postman — API testing with ease

Presentation by Nazar Lobur, 2025

🌐 What is API Testing?

  • HTTP-methods.
  • Code status.
  • Response body.
  • Structure and format.
  • Response time.
  • Erors handling.
  • Authorization.

🧪 Types of API-testing

Depending on the goal we test:

Functionality

Security

Productivity

Negative scenarios

Reliability

Errors handling

📦 Why i choose Postman?

Simple interface

Support tests with JavaScript

Save history

Support Authorization

📥 How to work with GET-requests

 

  • We retrieve a list of users.
  • Filter by parameters.
  • Check whether anything
    is displayed.

With GET-requests we are:

In case if request are broken i use console.

🔍 Query parameters = save time

Case sensitivity: createdAt ≠ CreatedAt

Wrong key = empty result or error

❗ Don't forget:

 

🗃️ Variables = cleanliness
and scalability

Benefits: 

  • Avoid duplication
  • Switch between environments
  • Update tokens, ID, URL

POST-requests: adding new data

POST-request allows to create new objects

POST /users/tenants {
"firstName": "Anna", 
"email": "anna@example.com",
 "phone": "123456789" 
}

 

🗑️ DELETE-requests: delete data

DELETE /users/tenants/123

help us to remove some data 

📏 Best practice of testing API (from experience)

  • Avoid hardcode — use variables

  • Always add validations

  • Structure collections by scenarios

  • Use pre-request scripts for tokens/data