I am having a strange issue when mocking the log field of a class. Running the same test twice shows an error the second time. This is an example of code:
class AccountConfigJSON {
static Logger log = Logger.getLogger(AccountConfigJSON.class)
def AccountConfigJSON(String jsonString) {
if (jsonString) {
json = new JSONObject(jsonString)
} else {
log.debug("No JSON string for account config. Will not parse")
}
}
}
and this is the specification
class AccountConfigJSONUnitSpec extends UnitSpec {
def loggerMock
def setup(){
loggerMock = Mock(org.apache.log4j.Logger)
org.apache.log4j.Logger.metaClass.static.getLogger = { Class clazz -> loggerMock }
}
def 'If jsonString is null, a log is written'(){
when:
new AccountConfigJSON("")
then:
1 * loggerMock.debug("No JSON string for account config. Will not parse")
}
def 'If jsonString is empty, a log is written'(){
when:
new AccountConfigJSON("")
then:
1 * loggerMock.debug("No JSON string for account config. Will not parse")
}
}
The second test fails showing
| Too few invocations for:
1 * loggerMock.debug("No JSON string for account config. Will not parse") (0 invocations)
but debugging the app using Idea, clearly it runs this sentence. Any idea?
Looks odd that the actual call is executed but the interaction in not recorded. You can get around with it by explicitly assigning the mocked logger to the class as below:
def setup(){
loggerMock = Mock(org.apache.log4j.Logger)
AccountConfigJSON.log = loggerMock
}
From the definition of "interaction", I think the above setup is the best way to go.
Is an Interaction Just a Regular Method Invocation?
Not quite. While an interaction looks similar to a regular method
invocation, it is simply a way to express which method invocations are
expected to occur. A good way to think of an interaction is as a
regular expression that all incoming invocations on mock objects are
matched against. Depending on the circumstances, the interaction may
match zero, one, or multiple invocations.
This only happens while dealing with static object properties in a class. The moment logger is defined non-static in the class under test, everything works as expected without the work around.
Related
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
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).
Say I've got a controller with an action that receives two parameters.
It invokes two services, one with each parameter, the services both return strings
each of those strings are passed as arguments to a template
the result is passed to Ok and returned.
I want to write a simple unit test that ensures:
1 - The correct services are invoked with the correct parameters
2 - The return values from the services are passed to the correct attributes of the template
What is the best way to do that?
Using Mockito with Specs2, I mock services to verify their method calls.
My controller is instantiated by Spring. That allows me to treat it is as a class instead of object. => That is essential to make controller testable. Here an example:
#Controller
class MyController #Autowired()(val myServices: MyServices) extends Controller
To enable Spring for controllers, you have to define a Global object, as the Play! documentation explains:
object Global extends GlobalSettings {
val context = new ClassPathXmlApplicationContext("application-context.xml")
override def getControllerInstance[A](controllerClass: Class[A]): A = {
context.getBean(controllerClass)
}
}
My unit test doesn't need Spring; I just pass collaborators (mocks) to constructor.
However, concerning the rendered template, I test only for the type of result (Ok, BadRequest, Redirection etc...).
Indeed, I noticed it's not easy at all to make my test scan the whole rendered template in details (parameters sent to it etc..), with only unit testing.
Thus, in order to assert that the right template is called with the right arguments, I trust my acceptance tests running Selenium, or a possible functional test, if you prefer, to scan for the whole expected result.
2 - The return values from the services are passed to the correct
attributes of the template
It's pretty easy to check for that..How? By trusting compiler! Prefer to pass some custom types to your template instead of simple primitives for instance:
phone: String would become: phone: Phone. (a simple value object).
Therefore, no fear to pass the attributes in a non-expected order to your template (in unit test or real production code). Compiler indeed will warn.
Here's an example of one of my unit test (simplified) using specs2:
(You will note the use of a wrapper: WithFreshMocks).
This case class would allow to refresh all variables (mocks in this case) test after test.
Thus a good way to reset mocks.
class MyControllerSpec extends Specification with Mockito {
def is =
"listAllCars should retrieve all cars" ! WithFreshMocks().listAllCarsShouldRetrieveAllCars
case class WithFreshMocks() {
val myServicesMock = mock[MyServices]
val myController = new MyController(myServicesMock)
def listAllCarsShouldRetrieveAllCars = {
val FakeGetRequest = FakeRequest() //fakeRequest needed by controller
mockListAllCarsAsReturningSomeCars()
val result = myController.listAllCars(FakeGetRequest).asInstanceOf[PlainResult] //passing fakeRequest to simulate a true request
assertOkResult(result).
and(there was one(myServicesMock).listAllCars()) //verify that there is one and only one call of listAllCars. If listAllCars would take any parameters that you expected to be called, you could have precise them.
}
private def mockListAllCarsAsReturningSomeCars() {
myServicesMock.listAllCars() returns List[Cars](Car("ferrari"), Car("porsche"))
}
private def assertOkResult(result: PlainResult) = result.header.status must_== 200
}
So, I came up with a cake pattern and mockito based solution:
given the service:
trait Service {
def indexMessage : String
}
trait ServiceImpl {
def indexMessage = {
"Hello world"
}
}
Then the controller looks like:
object Application extends ApplicationController
with ServiceImpl {
def template = views.html.index.apply
}
trait ApplicationController extends Controller
with Service {
def template: (String) => play.api.templates.Html
def index = Action {
Ok(template("controller got:" + indexMessage))
}
}
And the test looks like:
class ApplicationControllerSpec extends Specification with Mockito {
"cake ApplicationController" should {
"return OK with the results of the service invocation" in {
val expectedMessage = "Test Message"
val m = mock[(String) => play.api.templates.Html]
object ApplicationControllerSpec extends ApplicationController {
def indexMessage = expectedMessage
def template = m
}
val response = ApplicationControllerSpec.index(FakeRequest())
status(response) must equalTo(OK)
there was one(m).apply(Matchers.eq("controller got:" + expectedMessage))
}
}
}
I had a lot of trouble getting Mockito working.
It requires an extra dependency and I had a lot of trouble working out how to use the matchers in scala (I'm quite comfortable using it in java)
Ultimately I think the above answer is better, avoid using String and other primitive types where you can wrap them in task specific types, then you get compiler warnings.
Also I would generally avoid doing things like the "controller got:" prefixing in the controller.
It's there in this case so I can verify that it went through, in the real world that should be done by some other component (controllers are just for plumbing IMO)
In one of my unit tests, I am having some difficulty getting a mocked method to executed. I have the following test code:
void testExample() {
def mockICFService = new MockFor(ICFService)
...
//Mock the methods
controller.metaClass.icfList = { def person ->
println "icfList"
return [new IC(conceptId:'12345')]
}
mockICFService.demand.getAllIC(1..1) { def id, def withHist, def appId ->
println "mocking service"
return new Person()
}
...
def model = controller.detail()
}
Inside of detail in my controller class I create a Person via the ICFService's getAllIC(). This part works correctly. Later in the function, however, there is a call to icfList (which is defined in the controller). Through println's I have determined that the call is still being made, although it is returning an empty array. I believe that this is because the array is populated based on data in the servletContext, but in Unit Testing there is no access to that (hence my trying to mock it out).
Does anyone know how to force the test to use the mocked version of controller.icfList instead of calling the actual method in controller?
When I try your code, what blows up for me is the mocked service, and the part that works properly is the mocked-out icfList() method. The opposite of your observation, interestingly. For what it's worth, here's what I did:
First replace new MockFor() class instantiation with the mockFor() method. Then you need to inject the mock service into the controller.
def mockICFService = mockFor(ICFService)
controller.iCFService = mockICFService.createMock()
By doing the above, only the mocked versions of icfList() and getAllIC() get called, so you are not using the servletContext at all. Check out the Grails testing documentation for more info.
The test class below verifies that a simple HttpService gets content from a given URL. Both the implementations shown make the test pass, though one is clearly wrong because it constructs the URL with an incorrect argument.
To avoid this and correctly specify the behaviour I want, I'd like to verify that in the use block of the test case, I construct one (and only one) instance of the URL class, and that the url argument to the constructor is correct. A Groovy enhancement seems like it would let me add the statement
mockURLContext.demand.URL { assertEquals "http://www.foo.com", url }
but what can I do without that Groovy enhancement?
Update: Replaced "mock" with "stub" in the title, as I'm only interested in checking the state not necessarily the detail of the interactions. Groovy has a StubFor mechanism that I haven't used, so I'll leave my code as is, but I think you could just replace MockFor with StubFor throughout.
import grails.test.*
import groovy.mock.interceptor.MockFor
class HttpServiceTests extends GrailsUnitTestCase {
void testGetsContentForURL() {
def content = [text : "<html><body>Hello, world</body></html>"]
def mockURLContext = new MockFor(URL.class)
mockURLContext.demand.getContent { content }
mockURLContext.use {
def httpService = new HttpService()
assertEquals content.text, httpService.getContentFor("http://www.foo.com")
}
}
}
// This is the intended implementation.
class HttpService {
def getContentFor(url) {
new URL(url).content.text
}
}
// This intentionally wrong implementation also passes the test!
class HttpService {
def getContentFor(url) {
new URL("http://www.wrongurl.com").content.text
}
}
What does mocking the URL get you? It makes the test difficult to write. You won't be able to react to feedback the mock objects give you about the design of the API of the URL class, because it's not under your control. And if you don't precisely fake the behaviour of the URL and what it exposes about the HTTP protocol, the test will not be reliable.
You want to test that your "HttpService" object actually loads the data correctly from a given URL, copes with different content type encodings correctly, handles different classes of HTTP status code appropriately, and so forth. When I need to test this kind object -- one that merely wraps some underlying technical infrastructure -- I write a real integration test that verifies that the object really does use the underlying technology correctly.
For HTTP I write a test that creates an HTTP server, plugs a servlet into the server that will return some canned data, passed the URL of the servlet to the object to make it load the data, check that the loaded result is the same as the canned data used to initialise the servlet, and stop the server in the fixture tear-down. I use Jetty or the simple HTTP server that is bundled with JDK 6.
I'd only use mock objects to test the behaviour of objects that talk to the interface(s) of that object I've integration tested.
Putting on my "Programming in the Small" and "Unit test 100%" hat, you could consider this as a single method that does too many things. You could refactor the HttpService to:
class HttpService {
def newURLFrom(urlString) {
new URL(urlString)
}
def getContentText(url) {
url.content.text
}
def getContentFor(urlString) {
getContentText(newURLFrom(urlString))
}
}
This would give you a few more options for testing, as well as split out the factory aspect from the property manipulation. The testing options are bit more mundane then:
class HttpServiceTests extends GroovyTestCase {
def urlString = "http://stackoverflow.com"
def fauxHtml = "<html><body>Hello, world</body></html>";
def fauxURL = [content : [text : fauxHtml]]
void testMakesURLs() {
assertEquals(urlString,
new HTTPService().newURLFrom(urlString).toExternalForm())
}
void testCanDeriveContentText() {
assertEquals(fauxHtml, new HTTPService().getContentText(fauxURL));
}
// Going a bit overboard to test the line combining the two methods
void testGetsContentForURL() {
def service = new HTTPService()
def emc = new ExpandoMetaClass( service.class, false )
emc.newURLFrom = { input -> assertEquals(urlString, input); return fauxURL }
emc.initialize()
service.metaClass = emc
assertEquals(fauxHtml, service.getContentFor(urlString))
}
}
I think that this makes all the assertions that you want, but at the cost of sacrificing test readability in the last case.
I would agree with Nat about this making more sense as an integration test. (You are integrating with Java's URL library on some level.) But assuming that this example simplifies some complex logic, you could use the metaclass to override the instances class effictvely partially mocking the instance.
It's tough to mock out JDK classes that are declared final... Your problem, as you reference through the enhancement, is that there is no way to create a URL other than calling the constructor.
I try to separate the creation of these kinds of objects from the rest of my code; I'd create a factory to separate the creation the URLs. This should be simple enough to not warrant a test. Others take a typical wrapper/decorator approach. Or you may be able to apply the adapter pattern to translate to domain objects that you write.
Here is a similar answer to a surprisingly similar problem: Mocking a URL in Java
I think this demonstrates something that a lot of people learn after doing more testing: the code we write to make things more testable is meant to isolate what we desire to test from what we can safely say is already tested somewhere else. It's a fundamental assumption we have to make in order to do unit testing. It can also provide a decent example of why good unit tests aren't necessarily about 100% code coverage. They have to be economical, too.
Hope this helps.
What exactly are you expecting to have fail? It is not readily apparent what you are trying to test with that code. By Mocking URL.getContent you are telling Groovy to always return the variable content when URL.getContent() is invoked. Are you wishing to make the return value of URL.getContent() conditional based upon the URL string? If that is the case, the following accomplishes that:
import grails.test.*
import groovy.mock.interceptor.MockFor
class HttpServiceTests extends GrailsUnitTestCase {
def connectionUrl
void testGetsContentForURL() {
// put the desired "correct" URL as the key in the next line
def content = ["http://www.foo.com" : "<html><body>Hello, world</body></html>"]
def mockURLContext = new MockFor(URL.class)
mockURLContext.demand.getContent { [text : content[this.connectionUrl]] }
mockURLContext.use {
def httpService = new HttpService()
this.connectionUrl = "http://www.wrongurl.com"
assertEquals content.text, httpService.getContentFor(this.connectionUrl)
}
}
}