Grails Criteria not working in JUnit Test - unit-testing

Question

I'm trying to test search method in my grails app but I'm having a null pointer exception. I mocked the domain in my test as follows:
#TestFor(AuditController)
#Mock(Audit)
class AuditControllerTests {
void testSearch() {
populateValidParams(params)
def audit=new Audit(params)
audit.save(failOnError: true)
//Search existing customer
def model = controller.search()
assert model.auditInstanceList.size() == 1
assert model.auditInstanceList.size() == 1
}
}
I got NPE on model.auditInstanceList. Where it shouldn't be null. Here is the code in my controller:
def search = {
def query
def criteria = Audit.createCriteria()
def results
query = {
and{
if(params.customerName){
ilike("customerName", params.customer + '%')
}
if(params.siteName){
ilike("siteName", params.siteName + '%')
}
max:params.max
offset:params.offset
}
}
results = criteria.list(params, query)
render(view:'list', model:[ auditInstanceList: results,auditInstanceTotal:results.totalCount ])
}
What is going on with this?

Answer 1

Return model at the end of search. As in,
def search = {
...
render(view:'list', model:[ auditInstanceList: results, auditInstanceTotal:results.totalCount ])
[auditInstanceList: results, auditInstanceTotal:results.totalCount]
}

Answer 2

When testing a controller action that calls render(), model and view variables are automatically created and populated in your test. By doing def model = controller.search(), you are replacing the magic model with your own, assigning it to the return value of search(). The correct way to do your assertions is:
controller.search()
assert model.auditInstanceList.size() == 1
assert view == '/audit/list'

Answer 3

I don't know why but sometimes you need to remove model as a return value from controller's action. I use both version alternatively in case one of them fails:
// sometimes this one works
def model = controller.search()
assert model
// sometimes this one works
controller.search()
assert model
Edit: I think of two new possibilities why your action doesn't work:
try to change your action from closure and make it a method.
make sure you have no after filter. I've found this bug: http://jira.grails.org/browse/GRAILS-6825