How to assert equality of two closures - groovy

Question

In my work, I have methods to return closures as inputs for markup builders. So, for testing purposes, can we make an expected closure and assert the expected one equal to the one returned by one method? I tried the following code, but the assert failed.
a = {
foo {
bar {
input( type : 'int', name : 'dum', 'hello world' )
}
}
}
b = {
foo {
bar {
input( type : 'int', name : 'dum', 'hello world' )
}
}
}
assert a == b

Answer 1

I do not think it will be feasible to assert the closures even after calling them.
//Since you have Markup elements in closure
//it would not even execute the below assertion.
//Would fail with error on foo()
assert a() != b()
Using ConfigSlurper will give the error about input() since the closure does not represent a config script (because it is a Markup)
One way you can assert the behavior is by asserting the payload (since you have mentioned MarkupBuilder). That can be easily done by using XmlUnit as below(mainly Diff).
#Grab('xmlunit:xmlunit:1.4')
import groovy.xml.MarkupBuilder
import org.custommonkey.xmlunit.*
//Stub out XML in test case
def expected = new StringWriter()
def mkp = new MarkupBuilder(expected)
mkp.foo {
bar {
input( type : 'int', name : 'dum', 'hello world' )
}
}
/**The below setup will not be required because the application will
* be returning an XML as below. Used here only to showcase the feature.
* <foo>
* <bar>
* <input type='float' name='dum'>Another hello world</input>
* </bar>
* </foo>
**/
def real = new StringWriter()
def mkp1 = new MarkupBuilder(real)
mkp1.foo {
bar {
input( type : 'float', name : 'dum', 'Another hello world' )
}
}
//Use XmlUnit API to compare xmls
def xmlDiff = new Diff(expected.toString(), real.toString())
assert !xmlDiff.identical()
assert !xmlDiff.similar()
Above looks like a functional test, but I would go with this test unless otherwise there is an appropriate unit test to assert two markup closures.