What is API Testing?

1. Early error detection: Identifies problems early in development, before they are integrated into the user interface.
2. Increased efficiency: API tests are typically faster and less complex than GUI tests, allowing for more frequent and comprehensive testing.
3. Better integration: It ensures correct communication between different system components, which is crucial in microservice architectures.
4. Support for Agile methodology: Enables continuous testing and integration, which is in line with agile software development principles

1. Functionality verification: Verification that the API performs its tasks according to the documentation and specifications.
2. Performance testing: Evaluating the API’s response speed and its behavior under load.
3. Security testing: Verification of authorization, authentication and data protection mechanisms.
4. Reliability testing: Checking how the API handles errors and unexpected situations.
5. Testing documentation: Making sure API documentation is accurate and up-to-date.

1. Functional tests: Verify that the API works as expected and according to specifications.
2. Integration tests: Verify that the API works properly with other system components.
3. Performance tests: Evaluate the speed and stability of the API under various loads.
4. Security testing: Identifies potential vulnerabilities in API security.
5. Regression testing: Ensure that new changes have not adversely affected existing functionality.

1. Requirements analysis: Understanding API specifications and expected behavior.
2. Test Design: Create test cases covering various scenarios.
3. Configuration of the environment: Prepare the necessary tools and test environment.
4. Test execution: Conduct scheduled API tests.
5. Analysis of results: Evaluation of test results and identification of potential problems.
6. Reporting: Documenting test results and bugs found.

1. Postman: A popular tool for manual and automated API testing.
2. SoapUI: An open-source tool for testing SOAP and REST APIs.
3. JMeter: Used mainly for API performance testing.
4. Swagger: a tool for documenting and testing REST APIs.
5. Cypress: A framework for test automation, including API testing.

1. Test automation: Allows fast and repeatable execution of tests.
2. Testing different scenarios: Include both positive and negative test cases.
3. Performance monitoring: Regularly check response time and API behavior under load.
4. Validating input and output data: Ensuring that the API correctly handles different data formats and types.
5. Security Testing: Conduct API security testing on a regular basis.

1. Faster test execution: automated tests can be run much more frequently than manual tests.
2. Greater accuracy: Eliminate human error in the testing process.
3. Easier integration with CI/CD: Ability to integrate API testing into continuous integration and delivery pipelines.
4. Better scalability: The ability to easily increase the scope and number of tests.

1. Integration complexity: APIs often work with multiple systems, which can complicate the testing process.
2. Changing requirements: Frequent changes in API specifications may require continuous test updates.
3. Security: API security testing can be complicated and require specialized knowledge.
4. Performance: Simulating real API workloads can be difficult and require advanced tools.

1. Automatically run tests: API tests can be executed automatically after any change in the code.
2. Faster error detection: API problems can be identified early in the development process.
3. Continuous quality assurance: Regular API testing ensures continuous quality control.

1. Verification of authorization and authentication mechanisms: Verify that the API correctly manages access to resources.
2. Testing the handling of sensitive data: Making sure the API adequately protects sensitive information.
3. Checking for attack resistance: Testing APIs against common threats such as SQL injection and cross-site scripting.

1. Test coverage: Checking what percentage of API functionality is covered by testing.
2. Test execution time: Monitor how fast API tests are executed.
3. Number of errors detected: Track the number and type of errors found during testing.
4. API stability: An assessment of how often API tests fail after changes are made.

1. It is an integral part of the development process: API tests are performed regularly in each iteration.
2. Supports rapid delivery of value: Allows frequent and rapid verification of API changes.
3. Promotes collaboration: Testers and developers work closely together to define and execute API tests

In summary, API testing is a key component of quality assurance in modern software development. It allows early detection of errors, increases the efficiency of the testing process and supports agile development methodologies. Through automation and integration with CI/CD processes, API testing is becoming an integral part of the application lifecycle, contributing to more reliable and secure systems.