5 MAJOR CHALLENGES OF API TESTING AND HOW TO OVERCOME THEM.

An API (Application Programming Interface) provides protocols, rules, routines, logic, and tools for establishing the communication between different platforms and applications.  An API is the middle layer of a three-layered application pyramid, consisting of a data layer, a server layer, and a presentation layer. The data layer is concerned with data storage ,the presentation layers are concerned with the user interface and the server layer is composed of business logic that defines the way for users to interact with various features and functions.

APIs are one-stop-shop of software development 

Data is the most valuable asset in today’s technology-driven world, by the surge in connected devices, raising exponentially the volume of information produced every day. Data is critical for the businesses to scale and make customer-centric decisions. APIs are used as the way to expose business services to partners and customers. 

How API testing helps to excel the businesses 

APIs hold the key to digital transformation and also  provide the window for potential security breaches. Thus, API testing needs to validate the optimal implementation of APIs along with assessing them for security threats and risks. With the comprehensive API testing strategy, businesses can empower themselves by offering a reliable and secure platform towards their partners and customers. 

Top 5 challenges faced in API testing 

Building a sustainable and meaningful API testing practice within an organization can support test coverage and ensure reduced risk across internal and the public connections. Testing APIs means going beyond the GUI layer to dissect the application to its core, which is highly beneficial. However, there are many challenges faced by the organizations to successfully adopt a productive API testing process. 

01  Setting up of the Testing Environment 

Setting up the test environment with the most needed set of  API parameters and running it successfully is one of the critical challenges faced during the API testing. It is essential to start combining API tests with application data to ensure that API performs as expected over a set of known configurations.

02 Sequencing of the API Calls

There is a necessity that the API calls must appear in a specific order to test them effectively. This usually creates a typical problem for the testing team . Moreover,the  API sequencing becomes even more difficult while working with the multi-threaded applications or other complicated applications.

03 The API Versioning

Typically, versioning is also a primary cause for  increasing complexity in API testing.Most of the systems have a degree of depreciation that should be managed by an API with the help of versioning .The API must identify missing values and allocate some default value that will allow the old version to work .

04 Complexity with the Use Cases

API testing follows a different approach towards testing. API’s being the central hub of logic and gateway to data for interfacing applications , use cases are near-infinite in API testing.Therefore, number of required tests rapidly exceeds the competences of QA responsible for test case design .

05 Parameter Validation

API testers may also face problems with respect to validation of  parameters via the API requests. Testers need to make sure that all parameter data using the same string or numeric data type meet the length constraints, also confirm to a specified range of values and should fit with other test criteria.

How can we overcome the challenges of API testing ?

To overcome the above discussed challenges , a modern API testing approach can be adopted which consist of :

Phase 1 : Integration Level Testing

The integration test phase focuses on service interfaces and will make sure that the information shared and the interface behavior are working as per the provided requirement

Phase 2 : Process/ Orchestration Testing

This phase covers:

• Business logic
• Sequencing
• Exception handling
• Process decomposition (including service and process reuse)

Phase 3 : Security and Governance Testing

In this phase, SOA / API is combined with the Government and Regulatory compliance, which is incorporated into the entire lifecycle of the project. This phase includes Quality of Service policies on Security, Performance and Transactions.

• Regulatory policies
• Business policies
• Audit policies
• Infrastructure policies

Phase 4 : System Level Testing

This test phase will cover if  the technical solution is meeting the defined acceptance criteria provided by the stakeholders.

API Testing Tools

Because of the characteristics of API Testing, this cannot be possibly carried out manually. You will have to use some of the very good API testing tools to test the APIs. 

→ Postman

Postman is one of the best tools used for API testing. It has rich features and is an open source available free of cost. It has also been recommended by most of its users.

• Support in Automated Testing.
• Helps in the Exploratory Testing.
• Supports the RAML (RESTful API Modeling Language) and Swagger formats.
• Supports sharing of the knowledge within teams.

→  SoapUI

SoapUI is a great tool  for API testing as well as Web Service testing.

•  It provides help in the API Mocking and Virts.
• For the statistics and metrics, it would offer you the HTML reports, Printable reports, or data exporting in CSV and in  XML format.
• For data-driven testing, SoapUI supports test-data reading from various sources such as the XML properties, Excel file, JDBC sources, directories, and files.
• Tool  lets you use the scripts again.
• Tool offers numerous other features such as Click and Point testing, security scans, and Code Free testing.

→  Katalon Studio

• Provide support for both REST and SOAP requests, parameterization functionalities, and different kinds of commands.
• Provide support for the data-driven approach.
• Provide support for the CI/CD approach.
• Provide support for AssertJ, which is a great assertion library for creating fluent assertion using BDD style.
• Perfect tool  for both experts as well as engineers with the Scripting and Manual modes.
• You could use it for both exploratory as well as automated testing.
• Provide customizable and pre-built code templates.
• Sample projects are given for your quick reference.
• Provides Auto-formatting, Code inspection, and Auto-completion features for the code.
• Provide UI for creating, executing, and maintaining tests.

→  JMeter

This tool is highly recommended for testing Load and Performance of the web applications.

• This tool will let you use many different programming languages.
• Supports in testing Load and Performance of various applications, protocols, and servers.
• Replaying of the test results is possible with JMeter.
• Tool supports variable assertions and parameterization.
• Tool supports per-thread cookies.
• Tool supports a variety of reports and configuration variables.

→  Swagger.io

• Supports   API Design and Development.
• Provide support for  API Documentation.
• Tool provides support for  API Testing.
• Supports  API Virtualizations and Mocking.
• Supports  API Monitoring and Governance.

Conclusion

API testing is continuously booming across all the industries. The formal testing process should be defined and incorporated in API Life Cycle. Though we have multiple challenges in API testing, let us reduce the risk by implementing the solutions mentioned above and build a successful API system.