Grails - Testing Tag Libraries

Testing Tag Libraries

Unit Testing

TODO

Integration Testing

Testing tag libraries is actually pretty trivial because when a tag is invoked as a method it returns its result as a string. So for example if you have a tag library like this:

class FooTagLib {
   def bar =  { attrs, body ->
   	   out << "<p>Hello World!</p>"
   }
   def bodyTag =  { attrs, body ->
      out << "<${attrs.name}>"
           out << body()
      out << "</${attrs.name}>"   	
   }
}

The tests would look like:

class FooTagLibTests extends GroovyTestCase {
  void testBarTag() {
	   assertEquals "<p>Hello World!</p>", new FooTagLib().bar(null,null)
   }
   void testBodyTag() {
	   assertEquals "<p>Hello World!</p>", new FooTagLib().bodyTag(name:"p") {
	       "Hello World!" 
       }
    }
}

Notice that for the second example, {{testBodyTag}}, we pass a closure that returns the body of the tag. This is handy for representing the body as a String.