My Approach to Test Driven Development Part 2 - MXUnit, Coldspring and ColdMock
2008 August 28
Like the title says, this post will include code samples for setting up an MXUnit test case using ColdSpring and ColdMock. The goal of any test case are to isolate the component under test as much as possible. I find ColdMock to be a simple and powerful tool for achieving test isolation. For this example, I created a test case for my ConfigFactory which I mentioned in a previous post. TheConfigFactory component has a constructor dependency on the Environment Config component developed by Rolando Lopez which makes this a good case for mocking.
A common convention for test cases is to add the suffix "Test" to match the test case to the component being tested. I have my own convention for setting up tests withColdSpring bean definitions which I keep in a similarly named xml file. All test cases extend the BaseTestCase which contains a couple of methods to simplify test configuration with ColdSpring. The full code of the of the BaseTestCase follows.
A common convention for test cases is to add the suffix "Test" to match the test case to the component being tested. I have my own convention for setting up tests withColdSpring bean definitions which I keep in a similarly named xml file. All test cases extend the BaseTestCase which contains a couple of methods to simplify test configuration with ColdSpring. The full code of the of the BaseTestCase follows.
<cfcomponent displayname="tests.BaseTestCase" extends="mxunit.framework.TestCase" output="false">
<cfset variables.beansXML = "">
<cffunction name="setBeanFactory" access="private" output="false" returntype="void">
<cfargument name="beansXML" type="string" required="true">
<cfargument name="params" type="struct" required="false" default="#structnew()#">
<cfscript>
if ((not structkeyExists(request,"beanFactory")) or (comparenocase(variables.beansXML,arguments.beansXML) neq 0))
{
variables.beansXML = arguments.beansXML;
request.beanFactory = createObject("component" ,"coldspring.beans.DefaultXmlBeanFactory").init(StructNew(),arguments.params);
request.beanFactory.loadBeans(variables.beansXML);
}
</cfscript>
</cffunction>
<cffunction name="getBeanFactory" access="private" output="false" returntype="any">
<cfreturn request.beanFactory>
</cffunction>
</cfcomponent>
In the past I kept my ColdSpring reference in variables scope, but I found that when testing components based that rely on Transfer ORM, I can shave the time of tests considerably when I have multiple tests in the same test case. Whether you run the MXUnit HttpAntRunner, the eclipse plugin or a manually configured test suite within a browser they all run as a single request, so as you define more tests it helps to speed things up.
Here's what the ConfigFactoryTest.xml looks like.
<beans>
<bean id="mockFactory" class="tests.MockFactory" singleton="true" />
<bean id="EnvironmentConfig" factory-bean="MockFactory" factory-method="createMock">
<constructor-arg name="objectToMock">
<value>model.Environment</value>
</constructor-arg>
</bean>
<bean id="ConfigFactory" class="model.ConfigFactory">
<constructor-arg name="hostName">
<value>${hostName}</value>
</constructor-arg>
<constructor-arg name="environmentConfig">
<ref bean="EnvironmentConfig" />
</constructor-arg>
</bean>
</beans>
You can see how easy it is to mock the dependency using the ColdMock MockFactory. Below is the full code for my ConfigFacotry test case. The important thing to note is that the component display name is used to resolve the path to the ColdSpring bean definitions used in the test suite.
<cfcomponent displayname="tests.ConfigFactoryTest" extends="tests.BaseTestCase">
<cffunction name="setUp" access="public" returntype="void">
<cfset var beanDefFileLocation = expandPath('/' & Replace(GetMetadata(this).displayname,'.','/','all') & '.xml')>
<cfset var params = Structnew()>
<cfset params.hostName = "www.somedomain.com">
<cfset setBeanFactory(beanDefFileLocation,params)>
</cffunction>
<!--- Begin Specific Test Cases --->
<cffunction name="testGetSetting" access="public" returntype="void">
<cfscript>
var configFactory = "";
var env = getBeanFactory().getBean("EnvironmentConfig");
var settings = structNew();
settings["MyString"] = "my string";
env.mockMethod('getEnvironmentByUrl').returns(settings);
configFactory = getBeanFactory().getBean("ConfigFactory");
assertTrue(configFactory.getSetting("MyString") eq settings["MyString"]);
</cfscript>
</cffunction>
<cffunction name="testGetAllSettings" access="public" returntype="void">
<cfscript>
var configFactory = "";
var env = getBeanFactory().getBean("EnvironmentConfig");
var settings = structNew();
settings["MyString"] = "my string";
env.mockMethod('getEnvironmentByUrl').returns(settings);
configFactory = getBeanFactory().getBean("ConfigFactory");
assertTrue(StructCount(configFactory.getAllSettings()) eq 1);
</cfscript>
</cffunction>
<cffunction name="testOnMissingMethod" access="public" returntype="void">
<cfscript>
var configFactory = "";
var env = getBeanFactory().getBean("EnvironmentConfig");
var settings = structNew();
settings["MyString"] = "my string";
env.mockMethod('getEnvironmentByUrl').returns(settings);
configFactory = getBeanFactory().getBean("ConfigFactory");
assertTrue(configFactory.getMyString() eq settings["MyString"]);
</cfscript>
</cffunction>
<!--- End Specific Test Cases --->
</cfcomponent>
Most of my tests aren't this involved. Since my ConfigFactory has a constructor dependency on EnvironmentConfig, I pull it out of ColdSpring first, mock the getEnvironmentByUrl method to return a known structure before requesting the ConfigFactory. Truly powerful stuff!
I have attached a zip file of this sample test bed as an enclosure for folks to try out.