SOAP UI - Part 1 - Introduction

Introduction

SOAP UI is an excellent tool to test the web services. Though there are many tools available in the market to test the web service, I would prefer SOAP UI for its flexibility, ease of use and vast number of features. We have been using the SOAP UI to test various secure services, test the connectivity between SOA servers, Load testing and performance testing etc. I am not a full time tester and not an expert in SOAP UI tool, but this is an attempt to unleash the SOAP UI as a developer. To be honest, many features are learnt through trial and error. In this article, the following points are covered:

1. Downloading SOAP UI
2. First SOAP UI project
3. Adding Assertions

Background

While developing B2B application, web services plays a vital part since most of the services are exposed as web service. This enables a wide range of clients access the web service. It is really important that the web services adhere to the standard non-funtional requirements like minimum response time, no fault etc. as well as any rules imposed by the client. SOAP UI plays a major role in testing the fitness of a web service.

First SOAP UI project

Right, let us start with the first SOAP UI project. This SOAP UI project will test a simple interest calculator which is exposed as web service. I have chosen this, because, I don’t want to spend too much time explaining the business logic of the web service and that is also not the scope of this article. So, our simple interest calculator will "simply" calculate the simple interest using the formula,

Simple Interest SI = (Principal amount (P) x Number of years (N) x rate of interest (R)) / 100,

For example, If P = 10000, N = 2 yrs and R = 20% (which no banks will give nowadays), the simple interest would be,

SO = (P*N*R)/100 = 4000

In web service terms, the service will accept three parameters principal, number of years and rate of interest and return the interest as output. The sample code is given below;

 public class SimpleInterest : System.Web.Services.WebService
{
    //Default constructor
    public SimpleInterest()
    {
    }


    /// <summary>
    /// This method will calculate the simple interest
    /// </summary>
    /// <param name="principalAmount">Principal amount</param>
    /// <param name="rateofInterest">Rate</param>
    /// <param name="loanPeriod">Number of years</param>
    /// <returns>Simple interest</returns>
    [WebMethod]
    public double SimpleInterestcal(int principalAmount, float rateofInterest, int loanPeriod)
    {
        double interest = 0;
        return interest = (principalAmount * rateofInterest * loanPeriod) / 100;
    }
}

The sample request / response is given below.

Request

<?xml version="1.0" encoding="utf-8"?>
<soap12:Envelope
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:soap12="http://www.w3.org/2003/05/soap-envelope">
  <soap12:Body>
    <SimpleInterestcal xmlns="http://tempuri.org/">
      <principalAmount>10000</principalAmount>
      <rateofInterest>20</rateofInterest>
      <loanPeriod>2</loanPeriod>
    </SimpleInterestcal>
  </soap12:Body>
</soap12:Envelope>

Response

<?xml
version="1.0" encoding="utf-8"?>
<soap12:Envelope
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:soap12="http://www.w3.org/2003/05/soap-envelope">
  <soap12:Body>
    <SimpleInterestcalResponse
xmlns="http://tempuri.org/">
      <SimpleInterestcalResult>4000</SimpleInterestcalResult>
    </SimpleInterestcalResponse>
   </soap12:Body>
</soap12:Envelope>

Ok, so the web service is working fine. Now, lets go to the SOAP UI Part.

The end point of this service is;

http://localhost:54350/SimpleInterest/SimpleInterest.asmx?wsdl

Picture 1: Create a new SOAP UI Project. Using file menu, create a new SOAP UI Project.

Picture 2: Project is loaded in left pan. Double click request 1 will load the request / response tab

Picture 3: sample request / response

Edit the request tab and fill the values. Press the green button to get the response.

So, the SOAP UI project to test the simple interest calculator is working. One can edit the service to test with various values. If there is a schema violation, the SOAP UI client will throw error. For example, if the principal value which by definition is an integer field will throw error if a double or alphabet is sent.

For example, if the principal amount field was sent as 100ABCD, the response would be a SOAP fault thrown by client. Similarly for any violation in schema if the input field was enum will be handled by SOAP client and error will be thrown back. It is a good practice to define the most precise datatypes for the fields since it will avoid unnecessary validations at the server end.

Similarly, if there is a fault handler available at the service end, then the SOA fault sent by service will be caught and sent back. Again it is a very good practice to send back valid readable error message like "invalid principal amount" etc., rather than sending the stack trace.

Assertions

Assertions are more important because, the SOAP UI is used for testing the web service performance and therefore the fitness of a service can be established only by having some metrics to measure the performance.

Assertions can be added to the load test as well as against the request. The load test assertions are:

1. Max error
2. Step Average
3. Step TPS
4. Step Maximum
5. Step Status

The assertions that can be added on the test step are:

1. Invalid HTTP status code
2. JMS timeout
3. WS –Security status
4. Not SOA fault
5. Response SLA
6. Valid HTTP status code
7. SOAP response
8. Script assertion
9. WS –addressing response
10. Contains
11. Xpath match
12. Xquery match
13. Sensitive information exposure
14. JMS status
15. Schema compliance
16. SOAP fault
17. Not contains

A load testing of a web service must have as many assertions as required which tests various parameters of the service. In the follow up article, I will run a load test, which will have the following assertions.

1. Maximum error allowed in 3
2. Response SLA is 2 seconds
3. Contains the response code as "0" which indicates the successful execution
4. Not a SOAP fault and much more.

Points of interest

in this article we went through a brief introduction of SOAP UI tool. More on the load testing will be added in the follow up article.

History

• 1. 0.1 Initial version  -21st June 2012