How to mock EntityManager and Query with Spock? - unit-testing

Using spock I need to mock the calls to EntityManager/Query. The line of code I'm trying to mock is:
entityManager.createNativeQuery("nativeQuery").setParameter(1, param1).getResultList()
The mock of entityManager.createNativeQuery returns a null Query object. That then causes a failure because you can't call a method on a null object. And I consequently I can't mock the return of a result set list.
I've tried breaking the statement down into separate ones and accompanying mocks, but that hasn't worked either because I still end up with a null Query.
I don't know if I've got tunnelvision on this right now, or if this can't be mocked - at least with Spock.
All help appreciated!

What you need to do is to build a hierarchy of mocks which will be returning each other, starting with the last one:
Query:
def query = Mock(Query) {
setParameter(_, _) >> it //here as mock itself is returned
getResultList() >> [] //empty list
}
EntityManager:
def manager = Mock(EntityManager) {
createNativeQuery(_) >> query
}
And so on. While what you need to implement is doable it more or less indicates bad design: every time a mock returns a mock a fairy dies, so you should avoid such constructs. What you can do is to separate query building from it's execution - then mocking will be much easier. Sample spec:
def 'fairy has just died'() {
given:
def query = Mock(Query) {
setParameter(_, _) >> it //here as mock itself is returned
getResultList() >> [1] //empty list
}
def manager = Mock(EntityManager) {
createNativeQuery(_) >> query
}
expect:
manager.createNativeQuery("").setParameter(1,1).getResultList() == [1]
}

Related

Grails Spock Mocking an Object

I am new in unit-testing in Grails application using Spock. However I would like to ask the following question. Lets say I want to run a test for the following function testfun.
class TestFun{
boolean testfun(long userId, long orderId){
User user = User.findByUserId(userId)
if(user == null)return false
Order order = Order.findByUserAndId(user, orderId)
HashMap<String, Object> = orderContent
orderContent= order.orderContent // the order has an element orderContent for storing the elements that one user orders
if(orderContent!=null){
orderContent.put("meal",1)
order.orderContent = orderContent
return true
}
return false
}
}
The corresponding unit test in that case would be:
class TestFun extends Specification {
def setup() {
GroovySpy(User, global: true)
GroovySpy(Order, global: true)
}
def "test funtest"() {
User user = new User(2).save()
Order order = new Order(3).save()
when:
service.testfun(2,3) == result
then:
2*User.findByUserId(2) >> Mock(User)
1*Order.findByUserAndId(_ as User, 1)>> Mock(Order)
result == true
}
}
However, I think that I have to mock the order.orderContent and I do not know how to mock it. Right now the test fails, because the orderContent is null so the testfun returns false.
Can anyone help me on that?
There are several things going on here, and hopefully fixing them will help you get the test running and passing.
I can't recall for certain, but I believe GroovySpy is an old feature, that isn't used with Spock tests. Instead of using that to mock a domain class, you should be using the #Mock annotation before the class definition, to specify which domain classes you would like to mock.
While you can mock the domain classes, you'll also need to actually populate the in-memory database with those objects, either in a setup: block, or in a setup() method, if they are needed for multiple tests.
You mention creating mocks, and using the Spock Mock() method will create a mock of that object, but you don't want to use that for domain objects. It is more typically used for service classes that will be manually injected into your test class.
When saving a mock domain class, I would suggest including the parameters flush: true, failOnError: true, that way any validation that fails will be indicated immediately and on the appropriate line. Without this, you can get some strange errors to occur later in the tests.
I don't know what you're doing in the when: block, but you should not be doing an assertion with == at that point, do all of those in the then: block.
Given all of this, I think you test class should look more like this:
#Mock([User, Order])
class TestFun extends Specification {
def setup() {
// This object will have an id of 1, if you want a different id, you can either specify it, or create more objects
User user = new User(first: "john", last: "doe").save(flush: true, failOnError: true)
new Order(user: user).save(flush: true, failOnError: true)
}
def "test funtest"() {
User user = new User(2).save()
Order order = new Order(3).save()
when:
boolean result = service.testfun(1, 1)
then:
// Optionally you can just use "result" on the next line, as true will be assumed
result == true
}
}

Unit test grails with domain objects using GORM functions

I have the following piece of code inside a service class named OrderService in Groovy on Grails. I want to make a unit test for this class. User and Order are domain classed. A user has many orders.
boolean testfun(long userId, lond orderId){
User user = User.findByUserId(userId)
if(user == null)return false
Order order = Order.findByUserAndId(user, orderId)
if(order == null)return false
return true
}
The unit test that I am trying to write is the following (using Spock):
#TestFor(OrderService)
#Mock([User, Order])
class OrderServiceSpec extends Specification{
def "test funtest"() {
User user = new User(2)
Order order = new Order()
order.metaClass.id = 3// I want to assign the id of the order in domain
order.save()
user.addToOrders(order)
user.save()
expect:
service.testfun(2,3) == true
}
}
However this test fails because the order is null. Can anyone help me?
Another question is: is this test a unit test? or should I write an integration test in grails?
It depends on what you're actually trying to test, but this can be a unit test—I'd just recommend modifying it a little bit to isolate only the service method that you're interested in testing. You're not looking to test the domain classes at all, so it's best to mock/stub the behavior that you need from them to test the service functionality.
A good way to do this is with Spock's support for interaction based testing via mock objects. Basically we specify that when the service's testfun() method is called, we expect User.findById() to be called once and Order.findByUserAndId() to be called once as well. Spock then allows us to stub out each method call so that we specify what we want the method to return. When we run the test, the stub will be used, not the actual GORM method.
Some complexity lies with stubbing out static methods (like GORM methods), but you can use a GroovySpy to get the job done.
Also, I'm assuming you meant to use User.findById() instead of User.findByUserId()?
Something along these lines should work for you:
def "test funtest"() {
setup:
// Global so that it replaces all instances/references of the
// mocked type for the duration of the feature method.
GroovySpy(User, global: true)
GroovySpy(Order, global: true)
when:
def result = service.testfun(2,3)
then:
// No need to return real objects, so use a mock
1 * User.findById(2) >> Mock(User)
1 * Order.findByUserAndId(_ as User, 3) >> Mock(Order)
result == true
when:
result = service.testfun(2,3)
then:
1 * User.findById(2) >> null
result == false
}
Note that we've isolated the service method. Any collaborating objects (User and Order) are only being interacted with via stubs and we can test the functionality of the service method without worrying about GORM at all.

Grails unit test using grailsApplication

I have a controller that on the save method calls a thread to retrieve some files. The thread has start() in a domain that has this line-
RetrievalThread retrievalThread = grailsApplication.mainContext.getBean ('retrievalThread').
In my unit test I tried this and it worked(I'll keep the other lines omitted that have no bearing right now). Without this line an error occurs saying can't get mainContext on null object,talking about grailsApplication. .
Def mainContext = Mock(ApplicationContext)
MainContext.getBean(_) >>{ name ->
return new MockRetrievalThread()}
The mock thread doesn't do anything.
This test runs fine but, any test after this fail with a null pointer exception with no real information. Looks like a bunch of background grails stuff. Is there a way to clean this up or use something better than what I'm using?
I'm sure there's a way to clean this up in a tearDown, but I think there is a better way.
1.) I would use DI rather than going through grailsApplication.mainContext.getBean; is there a reason you are doing it this way?
class MyController {
def retrievalThread
getFiles() {
return [files: retrievalThread.getFiles(params.id)]
}
}
2.a.) Using DI, you can then just set the controller's retrievalThread to a new instance of MockRetrievalThread within your test.
void "test getFiles"() {
given:
controller.retrievalThread = new MockRetrievalThread()
when:
params.id = 1
def returnedFiles = controller.getFiles()
then:
// assertions
}
2.b.) Or skip the MockRetrievalThread altogether and mock the retrievalThread bean using the mockFor method, and then set the mocked version to the injected instance in your controller.
void "test getFiles"() {
given:
def retrievalThreadMock = mockFor(RetrievalThread)
retrievalThreadMock.demand.getFiles { Integer input ->
return ['file1', 'file2', 'etc.']
}
controller.retrievalThread = retrievalThreadMock.createMock()
when:
params.id = 1
def returnedFiles = controller.getFiles()
then:
// assertions
}
You can use integration testing instead to run the entire app, in order to avoid any beans not being injected.
grails create-integration-test org.bookstore.Book

Grails 2.4.4 : How do mock a transient service inside a domain?

I have been trying to figure this out for 2 days now and I am really stuck and frustrated. I have a domain object with a service which is being used for custom validation. The domain looks like this:
class Llama {
String name
transient myFetcherService
static transients = [
'myFetcherService'
]
static constraints = {
name validator: { val, obj ->
if (obj.nameExists(val) == true) {
//return some error here.
}
}
}
protected boolean nameExists(String name) {
List<Llama> llamasList = myFetcherService.fetchExistingLlamasByName(name)
if (llamasList.isEmpty()) {
return false
}
return true
}
}
Now, I have another Service, which simply saves a list of Llama objects. It looks like this:
class LlamaFactoryService {
public void createLlamas(List<String> llamaNames) {
llamaNames.each { name ->
new Llama(name: name).save()
}
}
}
In my test. I keep getting this error:
Failure: createLlamas should create Llammas (com.myLlamaProject.LlamaFactoryServiceSpec)
| java.lang.NullPointerException: Cannot invoke method myFetcherService on null object
I don't understand. In my tests, added a metaClass for the service in the "given" section. When it tries to save, it's telling that the service is null. This is what my test looks like:
given:
def myFetcherService = mockFor(MyFetcherService)
myFetcherService.demand.fetchExistingLlamasByName {def name -> return []}
Llama.metaClass.myFetcherService = myFetcherService.createMock()
when:
service.createLlamas(['Pablo','Juan','Carlos'])
then:
//some validations here....
I also tried using metaClass on the method nameExists() like:
Llama.metaClass.myFetcherService = { def name -> false }
, but it gives me the same nullPointerException as the one above. Could someone point me to the right direction? I'm a bit stuck. :(
Thanks in advance for reading and helping.
You're using a unit test and the general rule for unit tests is that beans generally aren't created for you, so you'll need to inject them yourself.
(Code edited to reflect the fact I misread the question)
I think you want a testing pattern something like:
given:
def mockMyFetcherService = Mock(MyFetcherService) // create the mock
Llama.metaClass.getMyFetcherService = { mockMyFetcherService } // inject the dependency
def returnList = [] // let's just define this here and you can re-use this pattern in other tests more easily
when:
service.createLlamas(['Pablo','Juan','Carlos'])
then:
// tell Spock what you expect to have happen with your Mock - return the List you defined above
3 * mockFetcherService.fetchExistingLlamasByName(_) >> returnList
If the injection of the service into the metaClass doesn't work (suggested here), you could always try using the defineBeans{} closure within the unit test itself (http://www.block-consult.com/blog/2011/08/17/inject-spring-security-service-into-domain-class-for-controller-unit-testing/).
Thus you could try:
defineBeans {
myFetcherService(MockMyFetcherService)
}
where MockMyFetcherService is defined in the same file that defines the test. This is the approach followed here:
See here for examples of more Spock interactions.
If you're using Grails 2.4.3 or below you'll need to put CGLIB in BuildConfig.groovy but I see here that it's already done for you in 2.4.4, so you should be ok just to use Mock(classname).

How do I mock local variables of a mocked class in a Spock test?

Let's say I have the following method in a service:
private void deleteItems(List<Item> itemsToDelete) {
def sql = new Sql(dataSource)
itemsToDelete?.each { Item item ->
sql.execute("DELETE FROM owner_item WHERE item_id = ${item.id}")
item.delete(flush: true, failOnError: true)
flushDatabaseSession();
}
}
How do I create a test for this method in the ItemServiceSpec? When I try it, I get either a DataSource "Must specify a non-null Connection" error or a nullPointerException on sql.
This is my existing test.
#TestFor(ItemService)
#Mock([Item])
#Build([Item])
class SubjectServiceSpec extends Specification {
...
def "delete items"() {
given:
Item item1 = Item.build().save(flush: true)
Item item2 = Item.build().save(flush: true)
Item.count() == 2
DataSource mockDataSource = Mock()
service.dataSource = mockDataSource
1 * deleteItems
when:
service.deleteItems([item1, item2])
then:
Item.count() == 0
}
}
What you are trying to do here, is to mock a dependency (DataSource) of a dependency (Sql). This normally leads to a situation, where you a not 100% aware of how the Sql interacts with the DataSource Object. If Sql changes private interaction with the Datasource in a Version Update, you have to deal with the situation.
Instead of mocking a dependency of a dependency you should the Sql Class directly. For this, the sql has to be some kind of explicit dependency that you can receive via DI or a method parameter. In this case you can just mock the execute call like so (choosen the way of a Expando-Mock, but you could also use Map or the Mock Stuff from Spock):
given:
def sqlMock = new Expando()
sqlMock.execute = { return 'what ever you want or nothing, because you mock a delete operation' }
service.sql = sqlMock
when:
service.deleteItems([item1, item2])
then:
assertItemsAreDeletedAndTheOwnerAsWell()
Thinking about the whole testcase, there a two major problems in my opinion.
The first one is, when you ask yourself what kind of certainty do you really get here by mocking out the whole sql stuff. In this case, the only thing that you are doing here is to interact with the db. When you mock this thing out, then there is nothing anymore that you could test. There is not many conditional stuff or anything that should be backed up by a unit test. Due to this, I would suggest to write only integration spec for this test-case where you have something like a H2DB for testing purposes inplace.
The second thing is, that you actually don't need the Sql Manipulation at all. You can configure GORM and Hibernate in a way do a automatic and transparent deletion of the owner of the item, if the item is deleted. For this, look at the docs (especially the cascade part) from GORM or directly in the Hibernate docs.
To sum it up: use cascade: 'delete' together with a proper integration test and you have a high amount of certainty and less boilerplate code.