In this age of technological advancements, communication between human beings has taken indirect route-via machines. Web services come into the picture here. Before delving deep into the uses of web services and why testing is required, it is important to understand what web services exactly are.
A web service enables communication between two applications or machines that exchange data, irrespective of their underline architecture and technology.
The need for a web service
Software applications are developed to be consumed by human beings where a person sends a request to a software service and it comes back with human-friendly results.
So, basically, web services are interactions across a network, irrespective of platform or the computer language used on either side. A web service implies a behind-the-scenes computer-driven action or group of actions, intelligently contained in a component, which in turn is part of a business process or flow.
That larger entity might be a web store or inventory manager or a booking system. This whole structure is part of an architecture known as SOA, where web services are the smallest components. Understanding that structure is essential to designing a test strategy.
Web services generally use HTTP or HTTPS protocol over the application layer of a computer network. Here, one application transfers data or sends requests as XML or JSON and receives the response, which is processed by the client application as a web service, irrespective of an underlying software platform, architecture, and technology.
Components of web services
The basic web services platform follows the XML message format and has an HTTP request and response. All the standard web services use the following components:
- SOAP (Simple Object Access Protocol)
- UDDI (Universal Description, Discovery, and Integration)
- WSDL (Web Services Description Language)
Testing web services
Web services is a common digital way to implement IT-based solutions for business tasks, where many interconnected systems are laser-focused on assembling these tasks to do everything you need.
Web testing involves the following steps:
- Understanding WSDL file definition
- Understanding the operations provided by the web service
- Reading XML Request message format, sent as SOAP request message
- Reading XML Response message format, received as SOPA response message.
- A simple local tool or test program that could send XML message request and receive the request as XML message response.
Web Service Testing with SOAP
This form of testing uses XML messages that include a WSDL catalog-style listing of web services, complete with their name(s), and input and output field parameter details. This serves as an ideal testing roadmap.
Web service testing with SOAP is well-suited for performing transactions that require multiple calls and need to enforce a strict client-server contract (like telecom services or anything financial). It works well with distributed enterprise environments.
It is highly structured for error-handling, accompanied by added built-in security (WS-Security, WS-Reliable Messaging, WS-Secure Conversation, etc.). It is designed for expansion and can use transport protocols besides HTTP. But, the structure does not guarantee that the variable content works as expected.
Benefits of web services testing
Some of the key benefits of web services testing are:
- They help you achieve your business requirements one step at a time. This may also include opening a new account, fetching an inventory price or changing someone’s account data.
- They help online businesses drive their success by doing data-specific critical work.
- It ensures that the web services work functions as expected.