I am a novice in web services. I am totally new to testing web services. A new project demands that I test the web services, and the customer is in favor of any open source tool. What is the approach to testing web services? Also Please suggest a tool(with minimal scripting) to test web services?
Check out SoapUI - one of the best web service test tools - plus it's free!!
They also have a "Pro" version which costs - you can do more stuff, like load testing etc., but the free version is quite good enough for most of your testing, I'd say!
Given a WSDL (online or stored as file), it'll create stubs for each method, which you can then use to create requests (as XML), fill in the blanks (the parameter values), and then you can send off your request to the web service and see what comes back as a response.
SoapUI also allows you to write scripted tests than can be run over and over again.
Excellent tool - can't praise it enough!
Marc
You might want to consider robot framework, possibly in combination with its seleniumm plugin. This makes it easy to create test scripts that fetch web-based resources and do assertions on the returned data.
robotframework has a ton of built-in keywords, there are additional libraries that do much more (again, the selenium library), and you can write additional keywords in java and python.
SoapUI is a great tool to test SOAP webservices. It allows you to test a SOAP client or a SOAP server.
Another very useful tool is Fiddler. Fiddler isn't necessarily aimed at testing webservices (it's a HTTP debugger), but since SOAP webservices run over HTTP, you can use it to testing. Another very important advantage of using Fiddler is the fact that you can test REST webservices also.