API testing plays an integral role in test automation, especially in the CI/CD process to ensure short release cycles and frequent changes. With API testing, app development teams no longer need to maintain scripts following the changes in the application under test’s UI.
Postman is a well-known tool for API development, testing, and management that is trusted by QA professionals. With Postman’s robust capabilities, a vastly growing community of developers has chosen this tool to be their primary API testing tool. Although it was first developed as a side project for simplifying API workflow and testing, it, now, has become a trustworthy solution utilized by 500,000 companies worldwide.
Pros and Cons of Postman in API Development
Postman can execute on all the three most current and prominent platforms (i.e. Windows, macOS, and Linux). And Postman also caters to different segments with two unique versions: a free version for individual developers to resolve their basic and simple requirements, and a commercial for businesses version with a full suite of features. Currently recognized as a collaboration platform for API development, the tool puts its focus on simplifying API building processes and streamlining team collaboration to make APIs creation better and faster.
In case you’ve just started with API Testing, you may find this article helpful: Introduction to API Testing
Pros
Ease of use: If you are new to Postman, all you need to do is sign up, download the tool, and log onto your new Postman account — start your testing journey herewith the free version.
Simplified API: Postman users can effectively use Postman’s comprehensive platform, plus a great deal of support for all possible HTTP methods.
Robust testing capabilities: Postman fully supports multiple testing environments, test checkpoints, and scheduling options.
Integration and collaboration powered: Postman Workspace enables real-time collaboration among teams with built-in version control.
Cons
Despite Postman’s strong capabilities to provide a holistic experience for web service testing, there are still some criteria that could be improved upon. While Postman is an excellent choice for manual API testing demands, the software world is currently shifting more towards automated testing tools which could make Postman obsolete over time.
Below are some of Postman’s critical limitations for automated testing needs:
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- Maintaining scripts and stability in performance is challenging due to test validation that has not been optimized.
- Reporting mechanism is insufficient and incompatible for today’s Agile teams.
- Rising cost and effort from repeated implementations of manual testing in the long term. Lacking CI/CD integrations and team collaboration support create a barrier to entry for Agile teams and non-technical members respectively.
Alternative Solutions to Overcome These Drawbacks in 2020
Katalon Studio
Katalon Studio offers an all-in-one testing platform for a wide range of project types. It supports all web, API, mobile, and desktop applications testing. The tool is continuously improving from time to time, empowering users to scale up their projects with solutions confidently.
In Katalon Studio, API testing is an all-inclusive capability with complete support for all types of REST, SOAP/1.1, and SOAP/1.2 requests. Moreover, there are diverse options for testers to execute their API project: Keyword-driven testing or Page Object Model (POM) testing.
Katalon’s IDE for API automation brings out the comprehensive features for scripting, debugging, and maintaining tests. Every tester is able to take advantage of a host of different elements, including auto completion, dual interface, code inspection, snippets, quick references, debugger, and more.
Katalon is also a bold choice to meet all needs for scaling and growing QA teams and enterprises with all-round integration capabilities. The tool embraces all requirements for CI or DevOps practices via its native plugins and supports integration with all popular tools for test projects.
Website: katalon.com
SoapUI
The other alternative tool we would recommend in this article is SoapUI, an API testing tool for both SOAP and REST testing. It comprehends the creation and execution of automated functional, compliance, regression, and load tests on Web API.
Except for functional testing features, SoapUI also provides load testing and security features. Users can make use of SoapUI’s scripting features: point and click or drag and drop.
SoapUI makes it simpler for testers, even for those lacking technical knowledge, by offering an easy-to-use interface. Depending on different demands, testers and businesses can choose to work with the open-source or the pro version.
Compared to Postman, SoapUI delivers a variety of features for API testing needs, including API discovery, SOAP testing, automated assertion creation, templated data insertion, and open-source standards.
Website: soapui.org
03 Best Practices to Leverage Postman Scripts in API Testing
1. Create API scripts with Postman and let the rest be executed by Katalon Studio
With Postman, the majority of testers can write their test scripts for API testing. Nevertheless, it may take their enormous effort to test while incorporating automation into the API scripts. Alternatively, you can utilize the integration with Katalon Studio to run automated tests with their ready-made Postman scripts.
Here, you can check for the quick guide on how to import your Postman scripts to Katalon Studio.
- Start to export your Postman collection to JSON. See the detailed description here.
- Then create a new API/Web Service project in Katalon Studio, and click on the Postman icon (on the toolbar).
- You will see the corresponding test objects to be imported into the Postman folder in Katalon.
2. Migrate all your API in Postman to Katalon Studio
Instead of putting too much effort in importing test scripts, there’s another way to move all your available artifacts in Postman to Katalon Studio. This approach allows you to use only one tool and make sure the consistency throughout the whole project.
We are showing you a brief tutorial to create your first API test with Katalon Studio.
- Step 1: Create a new project.
Firstly, go to File > New > Project, enter your project name, its location, and click OK to start a new project.
Once the project is created, in the Test Explorer, you can see a folder structure. This folder system, where you can start your first API test, will also be the place to keep all of the test resources.
- Step 2: Create the first API test
- Step 3: Create a new RESTful endpoint at Object Repository
Go to Object Repository > New > Web Service Request
Katalon Studio will store Web service endpoints for testing at Object Repository. You can either create a RESTful or a SOAP request at the “Create New Web Service Request” dialog.
At this step, you need to specify precisely in the “Request Type” field (since it is required to fill). On the contrary, the URL is optional; you can set this value later in the next step.
Click OK. You can input more details to complete the RESTful test with your first API test.
3. Migrate your Postman collections to SoapUI
As previously mentioned, SoapUI is another ideal choice to replace Postman for teams that mainly focus on API testing. This solution allows Postman users to seamlessly migrate from one tool to another. Most of the time Postman users migrating to SoapUI put more concentration on testing capabilities than mere functional testing with their APIs.
These following steps help you to import your Postman Collection to SoapUI.
- Export a Postman Collection
Firstly, you need to save it as a file once you start working with a Postman collection. In the Postman application in Chrome, choose your collection and click Download.
Click Collection v1 export option (SoapUI does not support v2 collections).
Select the place you want to save the collection and click Save.
- Import the Postman collection to SoapUI
Next, select File > Import Postman Collection.
In the Import Postman Collection dialog, select Browse, click the Postman collection to import.
Lastly, SoapUI will create a new project and import all APIs stated in the collection.
Conclusion
As previously mentioned, API testing still plays a significant role in the software testing market. Tools like Postman are also promising for the further development phase and offer users more added-values. However, it is critical for every business to select the tool that is the best fit for them and can scale up with their projects. In writing this article, we hope to provide you with an overview of the top API testing tools in the market, and we believe that it will help you make the most out of API automated testing solutions.
Reference: Best Practice to Refine API Testing