Data driven tests in Spock - groovy

Question

I'm rewriting some JUnit test into Spock to take advantage of the data driven test style.
I'm struggling a bit with how to provide the verification with something dynamic.
Here's what I have so far:
def "domestic rules"(from, to, oneWay, check) {
expect:
String mealResponse = getMealResponse(new BookingOptions.BookingOptionsBuilder().setFrom(from).setTo(to).setOneWay(oneWay).build());
check(mealResponse)
where:
from | to | oneWay || check
'MNL' | 'PEK' | true || assertNoMeals()
}
def assertNoMeals = {
assert JsonAssert.with(it)
.assertThat('$.links', hasSize(1))
.assertThat('$.links[0].rel', is("http://localhost:9001/api/docs/rels/ink/meal-allocations"))
.assertThat('$.links[0].uri', startsWith("http://localhost:9001/api/tenants/acme/meals/allocations/"));
}
Unfortunately, I get a NullPointerException at the line with the first row of data.
I guess thats because the closure is being run at that point, rather than just declared.
Is there a way to do this better?

Answer 1

Change
def "domestic rules"(from, to, oneWay, check) {
To
#Unroll
def "domestic rules from #from to #to one way #oneWay"() {

Answer 2

def "domestic rules"() {
when: 'get meals using certain parameters'
String mealResponse = getMealResponse(new BookingOptions.BookingOptionsBuilder().setFrom(from).setTo(to).setOneWay(oneWay).build())
then: 'the json response should contain some contents (improve the message here!)'
JsonAssert.with(mealResponse)
.assertThat('$.links', hasSize(1))
.assertThat('$.links[0].rel', is(somethingToUseInAssertions))
where:
from | to | oneWay || somethingToUseInAssertions
'MNL' | 'PEK' | true || 'just some example'
}
The above should help you get in the right track. Notice that you should have some values only in the examples. If you need some logic in the assertions, use a value which indicates what kind of assertion needs to be made... but it's a very bad idea to use a closure as an example.

Answer 3

If you really want to make your test hard to maintain and go ahead and use closures as "values" in your examples, then do something like this:
def "domestic rules"() {
when:
String mealResponse = getMealResponse(new BookingOptions.BookingOptionsBuilder().setFrom(from).setTo(to).setOneWay(oneWay).build())
then:
check(mealResponse)
where:
from | to | oneWay || check
'MNL' | 'PEK' | true || this.&assertNoMeals
}
boolean assertNoMeals(mealResponse) {
assert JsonAssert.with(mealResponse)
.assertThat('$.links', hasSize(1))
.assertThat('$.links[0].rel', is("http://localhost:9001/api/docs/rels/ink/meal-allocations"))
.assertThat('$.links[0].uri', startsWith("http://localhost:9001/api/tenants/acme/meals/allocations/"))
return true // pass!
}
I advise you to learn both Groovy and Spock before writing something that is more reasonable. It's not hard, but it does take at least a few hours!