Spock unit test that a validation throws an exception - validation

Question

I'm new to Spock and I have this class that I want to unit test. In the class there's a method that validates a product. To pass the validation the product must have fullPrice and this must contain all the other prices, otherwise an exception should be thrown.
class PriceValidator {
private final Logger logger = Logger.getLogger(MyService.class)
void validate (Product product) throws SubsystemException {
if (!product.fullPrice || !product.fullPrice.priceInclVAT || !product.fullPrice.priceExclVAT || !product.fullPrice.vat) {
String message = "No price found!"
logger.error(message)
throw new SubsystemException(
Subsystem.MySystem,
FailureCause.NO_PRICE_FOUND,
message
)
}
}
}
I have tried testing this in several ways without any luck. I'm guessing I need mocks, but that is also new to me. This is an example of a test that I have tried, resulting in "Test framework quit unexpectedly" (and all the prices are Strings):
class PriceValidatorTest extends Specification {
#Unroll
def "No price should throw an exception"() {
given:
PriceValidator priceValidator = new PriceValidator()
Product product = Mock()
when:
product.fullPrice != null
product.fullPrice.priceInclVAT = "100"
product.fullPrice.priceExclVAT = "70"
product.fullPrice.vat = null
priceValidator.validate(product)
then:
thrown(SubsystemException)
}
}
Anyone having a suggestion how to test the PriceValidator?

Answer 1

You need to test several cases, one of them would be:
def "No price should throw an exception"() {
given:
PriceValidator priceValidator = new PriceValidator()
Product product = Mock() {
getFullPrice() >> null
}
when:
priceValidator.validate(product)
then:
thrown(SubsystemException)
}
What You need to to is to mock the behavior of Product class (the line with >> rightShift operator). No it seems ready to be tested. Other scenarios, when price is filled should be tested in separate method. Any further questions?