Your Guide to Open Source API Testing Tools

Postman API Testing

Postman is an API platform that lets developers create, share, test and document APIs.

Postman is a very powerful platform. Some of the most notable features that support Postman API testing are the abilities to reuse APIs, group together related APIs using the ‘Collections’ feature, run grouped APIs with the ‘Collection Runner’ feature and generate code snippets that can be integrated into the APIs with the ‘Snippets’ feature. By using Newman with Postman (Newman is a command line executor for Postman tests), developers can also run their Postman collection from the command line. 

API testing with Postman provides multiple benefits, including the abilities to access files from the cloud, collaborate with team members, add test checkpoints, automate the process and debug the test results. Newman also allows integrating API test automation into Continuous Integration tools.

Swagger API Testing

Swagger files, aka OpenAPI definitions, allow developers to specify the operations and metadata of their APIs in machine-readable form. These definitions enable automating various processes around the API lifecycle, like testing.

In the OpenAPI vs. Swagger debate, the advantages of using Swagger include the abilities to collaborate on API design, share designed APIs and generate documentation easily. In addition, Swagger’s standardization reduces the risk of errors and ensures quality.

The Swagger Editor can be used for designing APIs. It is open source and is completely built on client-side JavaScript. The editor is simple to use and enables creating APIs in just a few steps.

To see your APIs when using Swagger for API testing, you can use Swagger UI. Swagger UI is an open source tool that generates a web page with the APIs generated by the Swagger specification. This UI enables developers to clearly see the endpoints they are testing so they can execute and monitor the API requests they sent and the results they received.

Taurus API Testing

Taurus is an open source testing tool that enables easy and simplified testing of a wide variety of tests, including API tests.

Taurus provides many advantages for running Taurus API tests. These include the use of self-explanatory, powerful dashboards that are easy to collaborate on, integrations with open source tools like JMeter, CI/CD compatibility and simplicity. 

Creating an API test in Taurus is easy and doesn’t require advanced coding skills. The entire test can be set up in a simple YAML file.

In addition to functional API tests, performance testing your APIs is also important. API performance testing ensures your servers are accessible to all users, even under a heavy load, and that there are no API delays. API performance testing tools detect failures on the API itself as well as on third-party components. We recommend using one of the three of the most useful performance testing tools: JMeter, Taurus, and BlazeMeter. 

REST Assured API Testing

REST Assured is one of the most powerful libraries for testing RESTful APIs. The syntax is very clean and easy to use. The main features that support REST Assured API testing include specification reuse, response validation, XPath verification and BDD syntax.

BlazeMeter Continuous API Testing

We’ve reviewed various ways to test your APIs. To achieve comprehensive API testing that is agile, complete and reliable, you need continuous API testing. This means shifting your API testing both left and right, i.e testing in both pre-production and post-production continuously. In addition, real continuous API testing must also include API monitoring.

BlazeMeter enables you to test and monitor your APIs throughout the entire SDLC, before production and in production.