Writing an Integration Test in Grails that will test DB persistence - grails

Question

My Integration-Test for my grails application is returning a null object when I try to get a domain object using grails dynamic get method.
This is a simplified example of my problem. Lets say I have a controller TrackerLogController that uses a service TrackerLogService to save an updated Log domain for another Tracker domain.
Domain Tracker:
class Tracker {
int id
String name
static hasMany = [logs: Log]
}
Domain Log:
class Log {
int id
String comment
static belongsTo = [tracker: Tracker]
}
Controller TrackerLogController save:
def TrackerLogService
def saveTrackerLog() {
def trackerId = params.trackerId
def trackerInstance = Tracker.get(trackerId)
Log log = TrackerLogService.saveTrackerLogs(trackerInstance, params.comment)
if( log.hasErrors() ){
//render error page
}
//render good page
}
Service TrackerLogService save:
Log saveTrackerLogs( Tracker tracker, String comment) {
Log log = new Log(tracker: tracker, comment: comment)
log.save()
return log
}
So now I want to write an Integration-Test for this service but I'm not sure if I should be writing one just for the simple logic in the controller (if error, error page else good page) I would think I would write a Unit test for that, and an Integration-Test to check the persistence in the Database.
This is what I have for my Integration-Test:
class TrackerLogServiceTests {
def trackerLogService
#Before
void setUp(){
def tracker = new Tracker(id: 123, name: "First")
tracker.save()
//Now even if I call Tracker.get(123) it will return a null value...
}
#Test
void testTrackerLogService() {
Tacker trackerInstance = Tracker.get(123) //I have tried findById as well
String commit = "This is a commit"
//call the service
Log log = trackerLogService.saveTrackerLogs(trackerInstance , commit)
//want to make sure I added the log to the tracker Instance
assertEquals log , trackerInstance.logs.findByCommit(commit)
}
}
So for this example my trackerInstance would be a null object. I know the Grails magic doesn't seem to work for Unit tests without Mocking, I thought for Intigration-Tests for persistence in the DB you would be able to use that grails magic.

Answer 1

You can't specify the id value unless you declare that it's "assigned". As it is now it's using an auto-increment, so your 123 value isn't used. It's actually ignored by the map constructor for security reasons, so you'd need to do this:
def tracker = new Tracker(name: "First")
tracker.id = 123
but then it would get overwritten by the auto-increment lookup. Use this approach instead:
class TrackerLogServiceTests {
def trackerLogService
private trackerId
#Before
void setUp(){
def tracker = new Tracker(name: "First")
tracker.save()
trackerId = tracker.id
}
#Test
void testTrackerLogService() {
Tacker trackerInstance = Tracker.get(trackerId)
String commit = "This is a commit"
//call the service
Log log = trackerLogService.saveTrackerLogs(trackerInstance , commit)
//want to make sure I added the log to the tracker Instance
assertEquals log , trackerInstance.logs.findByCommit(commit)
}
}
Also, unrelated - don't declare the id field unless it's a nonstandard type, e.g. a String. Grails adds that for you, along with the version field. All you need is
class Tracker {
String name
static hasMany = [logs: Log]
}
and
class Log {
String comment
static belongsTo = [tracker: Tracker]
}