Testing with Spock Framework
Spock is a testing and specification framework for Java and Groovy applications that combines the best features of JUnit, Mockito, and other testing tools.
Why Spock?
- Highly expressive specification language
- Built-in mocking and stubbing
- Parameterized testing
- Clear, readable test reports
- Integrates with JUnit runners
Basic Spock Test
import spock.lang.Specification
class MathSpec extends Specification {
def "maximum of two numbers"() {
expect:
Math.max(a, b) == c
where:
a | b | c
1 | 2 | 2
5 | 3 | 5
0 | 0 | 0
}
}Test Structure
Spock tests are structured in blocks:
def "should add two numbers correctly"() {
given: "two numbers"
def a = 5
def b = 3
when: "they are added"
def result = a + b
then: "the result should be correct"
result == 8
}Common Blocks
| Block | Purpose |
|---|---|
| given/setup | Setup test conditions |
| when | Perform the action |
| then | Assert the results |
| expect | Combine when+then |
| cleanup | Clean resources |
| where | Data-driven testing |
Mocking with Spock
def "should send notification when order is placed"() {
given: "a notification service and order processor"
def notificationService = Mock(NotificationService)
def orderProcessor = new OrderProcessor(notificationService)
when: "an order is placed"
orderProcessor.process(new Order())
then: "a notification should be sent"
1 * notificationService.send(_)
}Advanced Features
- Interaction testing: Verify method calls
- Stubbing: Define method return values
- Exception testing: Verify exceptions
- Shared objects: Reuse between tests
- Extensions: Custom test behavior
Integrating with Grails
Grails has built-in support for Spock:
# Create a Spock test in Grails
grails create-unit-test com.example.BookService