What is better to use: Postman or a full-fledged testing automation framework?

The choice between Postman and a specialized framework depends on the tasks, scale, and requirements of the project.

Postman is a tool best suited for manual API testing, rapid prototyping, debugging, and small automation scenarios.

Advantages of Postman:

• Easy to start and user-friendly.
• Intuitive interface.
• Wide functionality for manual testing (creating requests, working with environment variables, collections).
• Ability to write simple scripts for checks (tests) and pre-request scripts.
• Integration with Newman for running collections via command line.

Limitations of Postman for comprehensive automation:

• Limited support for complex scenarios and dependencies.
• Difficulties in managing large volumes of test data.
• Limited capabilities for generating detailed reports.
• Less flexible and extensible structure compared to full-fledged frameworks.
• Scripts are written in JavaScript, which may be a limitation for teams preferring other languages.

A full-fledged automation framework (e.g., Rest Assured in Java, Requests with pytest in Python, SuperTest in Node.js) offers broader capabilities for API testing automation:

Framework advantages:

• High flexibility and extensibility.
• Support for complex test scenarios, data flows, and dependencies.
• Improved management of test data (working with files, databases).
• Integration with various CI/CD tools, logging systems, and reporting tools (Allure, TestNG).
• Ability to write tests in the chosen programming language, simplifying integration with the rest of the project code and reusing logic.
• Enables building a reliable and maintainable test automation architecture.

Framework limitations:

• Higher entry barrier: requires knowledge of programming language and automation principles.
• Takes more time to set up and develop initial infrastructure.

Conclusion:

• Use Postman in the initial stages for manual testing, debugging, and writing simple automated tests or smoke tests.
• Transition to a full-fledged framework when there's a need to create a scalable, reliable, and integrated API testing automation system that requires complex logic, data management, and detailed report generation.

Often, an optimal approach is a combination: use Postman for quick exploration and debugging of APIs, then migrate the most important and complex scenarios to a full automation framework.