Grails: how is persisting of domain classes unit-tested?

[Chris Baron]

Hi,
how is persisting of domain classes unit-tested in Grails?
If i use the save method in the generated test class for my domain class "Task" a MissingMethodException is thrown in :

new Task(id: "1", description: "Bla").save()
 
groovy.lang.MissingMethodException: No signature of method: Task.save() is applicable for argument types: () values: []

The very same syntax works e.g. in BootStrap.groovy.

Thanks Chris

[Jon Dickinson]

Hi Chris,

The dynamic methods added by the Grails framework are not available in unit tests, unless you mock them, however, you can use the testing plug-in to do this for you. As of Grails 1.1 the testing plug-in is one of the core plug-ins, so there is no need to install it.

Here's a cut down example from Chapter 6 of my book, assume we have a MessageController that binds the 'title' and 'detail' parameters from a request onto a Message domain class. We could test this controller called the save method on the domain class like so:

import grails.test.GrailsUnitTestCase

class MessageControllerTests extends GrailsUnitTestCase {

    def savedMessages

    void setUp() {
        super.setUp()
        savedMessages = []
        mockDomain(Message, savedMessages) //mocking the domain class
        mockController(MessageController) //mocking the controller
    }

    void testMessageCanBeCreated() {
        def messageController = new MessageController()
        messageController.params.title = 'detail'
        messageController.params.detail = 'some detail'

        messageController.save() // executing the save action on the MessageController

        assertEquals('list', messageController.redirectArgs.action)
        assertEquals(1, savedMessages.size()) //assert the message has been saved
    }
}

Here we have asked the Grails testing plug-in to mock the Message domain class and controller. By mocking the domain class the unit test adds the GORM methods on, like save, list, get etc. and uses the list we have supplied savedMessages to temporarily store any messages that are saved. In this way we are able to assert that the message has actually been saved in the controller.

Cheers,
Jon.

[Chris Baron]

Hi Jon,
thanks for introducing these mock methods. That's a cool concept.
But i'm sorry to say that i have a Exception in my code that matches line 16 in your last code block

groovy.lang.MissingPropertyException: No such property: params for class: TaskController

My TaskController (that corresponds to your MessageController) has actually no property at all, except

def scaffold = Task

Am i missing something in the controller?
Thanks cb

[Jon Dickinson]

That's interesting. I have to say that I have never tested a scaffolded controller before as I haven't written any logic to require testing.

I have just quickly spiked what I think you are trying and it does fail but I get a different issue, namely the action closure does not exist. Now I am not entirely surprised by that, but I am able to set the behaviour on the params object.

Here's what I have, hope that helps:

//the domain class, under grails-app/domain
class Task {
    String name
}

//the controller class, under grails-app/controller
class TaskController { 
    def scaffold = Task
}

//the test class, under test/unit
import grails.test.GrailsUnitTestCase

class TasksTests extends GrailsUnitTestCase {

    def tasks

    public void setUp() {
        super.setUp()
        tasks = []
        mockDomain( Task, tasks )
        mockController( TaskController )
    }

    void testTaskCreate() {
        def taskController = new TaskController()
        taskController.params.name = 'first task' //no problems here

        taskController.save() //fails here, not entirely surprising

        assertEquals( 1, tasks.size() )
    }
}

I am using Grails 1.1, rather than 1.0 with the testing plug-in.

Cheers,
Jon.

[Chris Baron]

Gnnn,
i had the Task and not the TaskController in the mockController method
Now it fails at the same line.

I think i'll wait with testing until i'am beyond scaffolding and then your sample will be very helpful.


Thanks Jon

[mark neisler]

I use integration tests instead of unit test on domain classes for this very reason.

package gormapi

import grails.test.*

class ClientTests extends GroovyTestCase {
protected void setUp() {
super.setUp()
}

protected void tearDown() {
super.tearDown()
}

void testCrud() {
Client c = new Client()

c.setName "testClient"
c.setDescription "testing client domain object"
assertFalse(c.id>0)
assertTrue(c.save(flush:true))
}
}