In the last article, “How to Effectively Implement API Testing,” we learned about the API implementation concepts and their best practices. This article focuses on the practical challenges we faced while testing APIs and their best possible solutions.
As per the latest State of API report, there is a massive spike in the companies taking up API operations. API is the backbone of the eCommerce industry and plays a vital role in the IT, banking, finance, insurance, computer hardware/software, telecommunications, retail, and healthcare industries.
If properly implemented, API testing helps achieve strategic business goals by attracting multiple customers. Let us get into the top QA challenges of API testing and their solutions.
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Initial Setup of API Testing Automation
Automation helps reduce manual effort by identifying and automating frequent validations in order. This involves setting up the API systems, creating and running the test suites, which can be challenging. The time and effort required can occasionally lead to a lack of interest in the team.
Therefore, during the API design phase, identify skilled resources and keep the team motivated. After completing the first phase, once the infra setup and scripts are ready, ensure that the data and API requests are performing as expected.
As GUI is not available and API testing deals with data & endpoints, test cases should be properly written, covering the possible input/output combinations. The complexity rises when the number of parameters increases. Here are some of the factors you should consider.
1. Schema Changes
Schema serves as the blueprint that defines the API syntax and grammar of the test documents. So, when a schema is correctly applied to an input document, we can test whether the document is valid. You need to set up the schema to validate the response parameters such as mock server, documentation, tests, or monitors. Whenever there is a change in the API document, such as adding new features or updating existing ones, we need to update the schema accordingly. Maintain this throughout the testing process.
It is a good idea to run comprehensive API tests in Alpha and Beta environments. This will reduce the issue to 90% when tested in these environments. Store the schema JSON string in the Postman Environment variable.
You can also use some of the tools such as Postman, AJV, and BrijPad to validate the schema.
2. Parameters Validation
Communication between API & systems happens through the data that passes between these systems. This data is assigned to the parameters, and it’s crucial to validate these parameters with the data. Evaluating the parameters plays a vital role in the functioning of API systems. You need to create all possible parameter combinations of the configurations and assess different scenarios.
- To validate these parameters, consider the type of data the parameter uses, whether it fits within the assigned length/range, pass another validation, etc.
- Incorporating Constraint-Based Elimination techniques with Pair-wise Testing tools, Boundary value combinations, and Equivalent partitions will give good coverage of test cases.
- You can also incorporate continuous API Monitoring Systems, which will provide quick validation of the errors in the systems.
- Identify the non-critical apps and build the parameter combinations to those APIs during the initial phase.
3. Call Sequencing
API calls should be in a sequenced order that aligns with the functionality.
For example, to place an order, first, the product should be added to the cart. The series of calls involve login to the website->search the product->select the product->add the product to the cart->place the order.
Since the output of one API serves as the input of the next API, any discrepancy in the order of API calls results in the functional change of the system. This becomes more complex when multithreaded applications are involved.
Validate these sequences whenever there is a change in feature.
4. System Integration
Ensure that the API system works properly with the data tracking system. For example, a shipment platform that uses shipment tracking API tracks all the information across the available carriers and the outside platform. Here we need to validate all responses to ensure the call is working properly. This information is used to measure the API performance.
To test this effectively, you need to focus on the design phase, what applications are integrated with other systems. Since different applications have different requirements, do not test the critical integration systems in parallel. Implementing load testing in continuous delivery helps accomplish this challenge.
5. Limited Time
When the development timeframe is limited, there may be chances of delivering poor-quality APIs. This produces more defects during the testing phase, resulting in the team going back and fixing the issue.
Correct estimation and proper timelines in the development & testing phases can help minimize this risk.
6. Framework updates
Any changes to the product design or features can impact the existing API automation framework. Revisiting the existing scripts and updating them is a tedious task if the changes are enormous.
To overcome this, review the framework periodically and check if it supports the API testing. Check whether the framework is extendable, supports GUI tests, and can use the build management tools and API libraries.
7. Tools Selection
Not all tools support testing the API functional, mobile, security testing scenarios. Tools like Soap-UI, Apigee, Postman, Katalon studio can support end-to-end API testing. A thorough comparison of the tools helps to select the best tools that suit your project.
There may be a communication gap between the developers and testers when a new version is released without closing the previous one. This can cause a critical security risk as a hacker can access the previous parameters and access the API, leading to a breach of sensitive information. Proper open channel communication between the teams helps minimize the security issues and save time.
API testing is continuously booming across all industries. The formal testing process should be defined and incorporated in the API Life Cycle. Though we have multiple challenges in API testing, let us reduce the risk by implementing the solutions mentioned above and build successful API systems.
This post was published under the Quality Assurance Community of Experts. Communities of Experts are specialized groups at Modus that consolidate knowledge, document standards, reduce delivery times for clients, and open up growth opportunities for team members. Learn more about the Modus Community of Experts program in this article.