API is the acronym for Application Programming Interface, which is a software intermediary that allows two applications to talk to each other. For example, fleet management systems are using Google Map APIs to display routes and distances in their applications. APIs are not confined to any domain, they can be applied to almost any type of application.

About API Testing

API testing involves validating APIs directly as part of the end-to-end testing during the Integration testing phase. Every API is expected to work the way it is coded, i.e., it is functionality specific. These APIs results may differ based on the various types of input provided. By performing API testing, we can make sure that APIs are returning the appropriate response (in the format expected) and react properly to corner scenarios such as failures and wrong inputs, timely response, and security attacks.

Three-Layer Architecture

A Three-tier architecture or 3 layer Architecture is majorly composed of the 3 major components.

  • Presentation Tier/User Interface Layer/Application Layer(UIL)
  • Middle Tier/Business Logic Layer(BLL)
  • Database Access Layer(DAL)
API Three-Layer Architecture

Test for Holistic API Testing

Below are a few types of testing we perform on APIs to check if the functionality is working fine.

  • Functionality Testing: Validate if the API is working as expected or not based on the business logic or functional requirement.
  • Reliability Testing: Check if the API can be consistently communicating/interacting and lead to consistent results
  • Negative Testing: Checking for every possibility of wrong input that the user may supply
  • Security Testing: Includes what type of authentication and encryption is required and how sensitive data is protected
  • Penetration testing: Testing the application to find different kinds of vulnerabilities that an attacker could crack
  • Discovery Testing: The testing team should manually execute a group of calls documented within the API like confirming that a selected resource exposed by the API may be created, deleted, or listed as applicable
  • Documentation: The test team needs to ensure that the documentation has the required information to interact with the API.
  • Usability Testing: Validate whether the API is easy to access and user-friendly
  • Automated Testing: All the repetitive test scenarios should be automated using an appropriate automation tool so that testing time can be reduced.

Challenges Encountered During API Testing

  • The main challenges in Web API testing are Parameter Combination, Selection of Parameter, and Sequencing the Calls
  • It makes it difficult to provide input values as there is no GUI available to test the application
  • Unavailable access to Source or Target Systems
  • Consuming systems lack the proper flow of business information
  • Existence of software ambiguous requirements
  • Existence of apparent trouble obtaining and creating test data
  • Available Production sample data is not able to cover all the possible business processes

Solutions for API Testing Challenges

To overcome the above challenges, the business team should come up with a robust approach, which is useful for the overall business in terms of doing API testing activities accurately.

  • Framework driven API testing
  • Layered architecture which addresses the basic Security of API
  • Parsing approach for testing parameters
  • Support for every validation parameter
  • Inputting structured test data
  • Reusable test scripts
  • Creation of use case-based test suite for each API
  • Creation and maintenance of Smoke, Regression test suites on each build in parallel
  • Documentation is mapped to the API test framework

XTIVIA’s Comprehensive Capabilities for API Testing Services

XTIVIA supports many clients with their API testing solutions producing effective results within quick test cycles, with zero defect leakage to production and significantly meeting the production go-live timelines.

If you are looking for API testing solutions or implementation requirements, XTIVIA’s testing experts are available to help you out with your projects.

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