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API Testing for Reaching Quality and Coverage Goals
Today’s distributed software environments incorporate a variety of APIs with every interface your software touches, from mobile to microservices. Each API has to be continuously tested and verified to ensure your software functions as it should. Parasoft’s API testing platform makes quick, efficient, and intelligent work of such requirements.
Why Is API Testing Important?
To ensure a pleasant and successful user experience with your software application, it’s important to test it thoroughly. This means verifying the underlying operation of the code and its interactions with other systems and services.
UI testing alone cannot guarantee that the software works as expected. API testing assesses the application’s functionality, reliability, and performance so you can have confidence that you’re delivering high-quality software.
API testing focuses on
- Validating business logic.
- Ensuring accurate data responses.
- Assessing performance issues.
- Identifying potential security risks.
All of these areas are critical for the correct operation of your application.
Failure to perform sufficient API testing can result in
- Release delays
- Production downtime
- High rework costs
- Loss of revenue and more
Proactive and extensive API testing produces better software.
Parasoft’s API testing platform enables you to proactively manage change by automatically monitoring APIs and services and visually highlighting where updates have occurred.
Use dynamic application security testing (DAST) to perform penetration testing as part of the development workflow to identify potential security risks earlier.
Top 5 API Testing Best Practices
For APIs to perform reliably including addressing security concerns, we present five top test practices.
1) Test a wide span of corner cases and conditions and use automated validation extensively.
A high level of automation provides an array of functional test scenarios which you can replicate systematically.
Use an intuitive interface to automate complicated cases over databases, microservices, the messaging layer, etc. This includes:
- Specifying automated test cases along a wide range of test types and protocols that developers use for APIs like HTTP/REST, Swagger, Kafka, MQ, JSON, EDI, JMS, and fixed-length messages.
- Parameterization of validations, test loads, and configurations from test cases, data sources, or variables.
- Definition of high-level test logic but without scripting.
- Visualization of how events and messages move through architectures while tests execute.
- Automation of full omnichannel validation along numerous endpoints and interfaces included in end-to-end test cases.
2) APIs continually change, which presents risks in security and quality for companies that don’t keep up.
Therefore, it’s essential to recognize when API changes occur and easily, quickly, and accurately update test assets to align.
The key is to develop a system that assesses changes needed for current tests and then updates them or even creates new tests. This can substantially reduce the time and effort it takes to be sure that your tests do not fail as a result of unexpected changes and that they don’t ignore new functionalities.
3) Use service virtualization for simulated test scenarios.
This allows you to create simulated test cases, which in turn allows you to view behaviors of dependent resources that you may have a hard time accessing, that you may have difficulty configuring for testing, or that are not yet available.
These resources might be web services, databases, mainframes, or third-party applications, among others. You can use web service virtualization together with OS and hardware virtualization to gain access to the required environments. Combined, this allows you to test faster, earlier, and more thoroughly.
You can apply service virtualization in two ways with regard to API testing:
- Simulate access to the behavior of the dependent resource, such as a database, a mobile app, a third-party service, or a legacy system.
- Simulate your API’s behavior by developing a test scenario API users can create and test for that doesn’t affect the production product. This also allows development and subsequent testing even if APIs are not yet complete.
4) Use service virtualization for extensive performance testing.
APIs are highly exposed. Thus, a great potential for volatile and unpredictable traffic exists. It’s wise to use broad performance testing to determine if your API meets expectations when it encounters surging demand or erratic behavior. Here are some examples.
Service virtualization allows you to create simulated test scenarios that assist you in testing various performance environments that are normally problematic to create in a test situation. You can test conditions like timing, delay, and latency to replicate typical, peak, and slow performance in an effort to plan for a cloud burst or someone accessing the API from a remote location on another continent.
In addition, you can create various failure and error situations that testers often find hard to reproduce in the actual program – like if your APIs use Amazon Web Services, you can create a scenario that simulates a situation where AWS is offline.
You can also configure a wide range of situations in dependent systems in order to discover if your APIs deliver proper responses under non-ordinary conditions and also if they fail reasonably well.
You may replicate links to third-party applications, which can negate any risk your tests may have on services that you are not normally allowed to attack with test data or for which you are not budgeted.
5) Test broadly for security issues using service virtualization.
APIs unfortunately offer a large surface attack area. To help stop attackers and major security problems, use a multi-faceted test approach. This ensures that you have written the necessary measure of security into the application. The approach includes:
- Creating a wide range of penetration and attack situations that involve injections, parameter fuzzing, big payloads, and so on.
- Implementing complex encryption, authentication, and access-control testing situations.
- Running penetration attacks aimed at existing operational test situations.
- Monitoring the backend as you test to discover if security has been compromised.
As a money saver, service virtualization allows non-security experts to perform tests because they are not writing code but simply executing proven tests in a wide variety of scenarios. And service virtualization enables you to target your API’s responses to a variety of dependency security behaviors and in numerous attack situations.
How to Get Started Testing APIs
Testing APIs focuses on ensuring that a development and QA team does what it is supposed to do, guaranteeing that applications perform and function properly, and are reliable and secure.
Automated API testing avoids human error and drudgery and is therefore far superior to manual testing. To prevent bugs early in the software development lifecycle, we recommend incorporating automated API testing into your continuous integration testing pipelines.
Get details and guidance on how to choose the right API testing solution for your organization.
Parasoft’s API testing platform is widely recognized as best-in-class, with innovative tooling and broad support for over 120 message formats and protocols. With visual drag-and-drop tooling, users can create the most complex test scenarios without having to write a single line of code. Things like test flow logic, complex assertions, looping, data driving, and keyword association, such as BDD with Cucumber, can all be easily built with minimal technical experience.
Additionally, API test suites can be reused for nonfunctional validation, including load, performance, and API security testing. This increases application coverage and quality with minimal rework and effort.
Partner with Parasoft to improve your API testing.
Frequently Asked Questions
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