API Testing Questions and Answers for Viva

Answer-1: API Testing is a type of software testing that involves testing the application programming interfaces (APIs) directly to ensure their functionality, reliability, performance, and security.

Answer-2: API Testing is important because it validates the core functionality of an application and ensures that different software components can communicate with each other seamlessly.

Answer-3: The different types of API Testing include:

Answer-4: Common tools for API Testing include Postman, SoapUI, JMeter, Swagger, REST Assured, and Karate DSL.

Answer-5: RESTful API is an architectural style for designing networked applications. It relies on a stateless client-server communication protocol, typically over HTTP, and uses standard HTTP methods like GET, POST, PUT, DELETE, etc., for communication.

Answer-6: SOAP (Simple Object Access Protocol) API is a protocol for exchanging structured information in the implementation of web services. It relies on XML for message exchange.

Answer-7: Here are some of the main differences between SOAP and RESTful APIs:
SOAP API uses XML format, while RESTful API typically uses JSON format.
SOAP API requires more bandwidth and resources compared to RESTful API.
SOAP API supports XML-RPC, while RESTful API does not.
RESTful API is more lightweight and easier to implement than SOAP API.

Answer-8: HTTP methods define the actions that a client can perform on a resource. Common HTTP methods used in API Testing are GET, POST, PUT, DELETE, PATCH, etc.

Answer-9: GET method is used to retrieve data from the server, while POST method is used to submit data to the server.
GET method appends data to the URL, while POST method sends data in the request body.

Answer-10: An endpoint is a specific URL where an API service can be accessed. It represents the location where resources can be interacted with using HTTP requests.

Answer-11: JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy for humans to read and write, and easy for machines to parse and generate. It is often used in RESTful APIs for data transmission.

Answer-12: Here are some of the main differences between JSON and XML:
JSON is more lightweight and readable compared to XML.
JSON supports simpler data structures than XML.
JSON is easier to parse and generate compared to XML.
JSON uses less bandwidth than XML.

Answer-13: The key elements of an API request include:
Endpoint URL
HTTP Method
Headers
Request Body (optional)

Answer-14: Authentication is the process of verifying the identity of a user or system. In API Testing, authentication ensures that only authorized users can access the API resources.

Answer-15: Common authentication methods used in API Testing are:
Basic Authentication
OAuth
API Keys
JWT (JSON Web Tokens)

Answer-16: Status code is a three-digit numeric code returned by the server in response to an HTTP request. It indicates the status of the request, such as success, failure, redirection, etc. Common status codes include 200 (OK), 404 (Not Found), 500 (Internal Server Error), etc.

Answer-17: Headers provide additional information about the request or response, such as content type, authorization token, cache control, etc. They are used to pass meta-information between the client and server.

Answer-18: Parameterization is the process of replacing hard-coded values in API requests with variables or data parameters. It allows for testing the same API with different input values.

Answer-19: Mocking is the process of simulating the behavior of external dependencies or components in order to test the functionality of an API in isolation. Mocks are used to emulate the responses of external systems.

Answer-20: API Documentation provides information about the endpoints, methods, parameters, request and response formats, authentication requirements, etc., of an API. It helps developers understand how to use the API correctly.

Answer-21: Regression Testing is the process of retesting the existing functionalities of an application to ensure that new changes or updates have not affected the existing functionalities adversely.

Answer-22: Validation Testing ensures that the product satisfies the specified requirements and meets the customer's expectations.
Verification Testing ensures that the product is being built according to the requirements and specifications.

Answer-23: Load Testing is a type of performance testing that involves testing the behavior of an API under varying levels of load or traffic. It helps identify performance bottlenecks and scalability issues.

Answer-24: Rate Limiting is a technique used to restrict the number of API requests that a client can make within a certain period of time. It helps prevent abuse or misuse of the API resources.

Answer-25: Boundary Value Analysis is a testing technique used to identify errors at the boundaries of input ranges. It involves testing the minimum and maximum boundary values, as well as values just inside and outside the boundaries.

Answer-26: Equivalence Partitioning is a testing technique used to divide the input data into partitions or equivalence classes. It helps reduce the number of test cases while ensuring adequate test coverage.

Answer-27: Fuzz Testing is a testing technique that involves providing invalid, unexpected, or random data as inputs to an API in order to uncover vulnerabilities, security flaws, or unexpected behaviors.

Answer-28: Stubs are used in bottom-up integration testing to simulate the behavior of lower-level modules that have not yet been developed.
Drivers are used in top-down integration testing to simulate the behavior of higher-level modules that call lower-level modules.

Answer-29: Code Coverage Analysis is a metric used to measure the percentage of code lines, branches, or paths covered by the test cases. It helps assess the effectiveness of the test suite and identify areas of the code that are not adequately tested.

Answer-30: Mock Servers are used to simulate the behavior of real servers and endpoints during API Testing. They allow developers to test the client-side code without relying on the availability of the actual server.

Answer-31: Synchronous APIs wait for a response from the server before proceeding with the next operation.
Asynchronous APIs allow the client to continue with other operations while waiting for a response from the server.

Answer-32: Chaining Requests is a technique used to link multiple API requests together, where the output of one request becomes the input for another request. It helps simulate complex user workflows or scenarios.

Answer-33: Content-Type is an HTTP header that specifies the media type of the data sent in the request or response body. Common Content-Types include application/json, application/xml, text/plain, etc.

Answer-34: CORS is a security feature implemented by web browsers to restrict the resources that a web page can request from another domain. It helps prevent unauthorized access to sensitive data.

Answer-35: Positive Testing involves testing the application with valid inputs to verify that it behaves as expected under normal conditions.
Negative Testing involves testing the application with invalid inputs or unexpected conditions to verify that it handles errors gracefully.

Answer-36: API Versioning is the practice of managing different versions of an API to ensure backward compatibility and smooth transition for existing clients when new features or changes are introduced.

Answer-37: Deprecation is the process of marking a feature or functionality of an API as outdated or obsolete. It typically precedes the removal of the feature in future versions of the API.

Answer-38: Cache Control is an HTTP header that specifies caching directives for the response. It allows the server to control how the response is cached by the client or intermediary caches.

Answer-39: Common security vulnerabilities in API Testing include:
Injection Attacks (e.g., SQL Injection, XSS)
Broken Authentication
Insecure Direct Object References
Cross-Site Request Forgery (CSRF)
Security Misconfiguration

Answer-40: API Monitoring involves continuously monitoring the performance, availability, and reliability of APIs in production environments. It helps identify and resolve issues before they impact end-users.

Answer-41: API Gateway is a server that acts as an intermediary between clients and backend services. It provides functionalities such as authentication, authorization, rate limiting, logging, and monitoring for APIs.

Answer-42:
Mocking involves creating objects that simulate the behavior of real components or systems.
Stubbing involves replacing a real component or system with a simplified version that returns predefined responses.

Answer-43: Contract Testing is a testing approach where the interactions between different services or components are verified against predefined contracts or specifications. It helps ensure that services communicate correctly with each other.

Answer-44: API Health Checks are periodic checks performed on APIs to ensure that they are functioning correctly and meeting the defined service-level agreements (SLAs). They help detect and address issues proactively.

Answer-45: API Orchestration is the process of integrating multiple APIs to automate workflows or business processes. It involves coordinating the execution of API calls in a specific sequence to achieve a desired outcome.

Answer-46: Mocking involves creating objects that simulate the behavior of real components or systems.
Stubbing involves replacing a real component or system with a simplified version that returns predefined responses.

Answer-47: Contract Testing is a testing approach where the interactions between different services or components are verified against predefined contracts or specifications. It helps ensure that services communicate correctly with each other.

Answer-48: API Health Checks are periodic checks performed on APIs to ensure that they are functioning correctly and meeting the defined service-level agreements (SLAs). They help detect and address issues proactively.

Answer-49: API Orchestration is the process of integrating multiple APIs to automate workflows or business processes. It involves coordinating the execution of API calls in a specific sequence to achieve a desired outcome.

Answer-50: Understanding API Specifications
Handling Authentication and Authorization
Data Parameterization and Test Data Management
Testing for Security Vulnerabilities
Ensuring Scalability and Performance
API Versioning and Compatibility
Handling Asynchronous Operations
Managing Dependencies and Mocking/Stubs
Monitoring and Reporting API Health
Integration with Continuous Integration/Continuous Deployment (CI/CD) pipelines.