Spock supports JUnit rules out of the box. We simply add a rule with the @Rule annotation to our Spock specification and the rule can be used just like in a JUnit test. The Spring Boot project contains a JUnit rule OutputCapture to capture the output of System.out and System.err.
In the following example specification we apply the OutputCapture rule and use it in two feature methods:
package com.mrhaki.spock
@Grab('org.spockframework:spock-core:0.7-groovy-2.0')
import spock.lang.*
@Grab('org.springframework.boot:spring-boot:1.2.1.RELEASE')
import org.springframework.boot.test.OutputCapture
class CaptureOutputSpec extends Specification {
@org.junit.Rule
OutputCapture capture = new OutputCapture()
def "capture output print method"() {
when:
print 'Groovy rocks'
then:
capture.toString() == 'Groovy rocks'
}
def "banner text must contain given messagen and fixed header"() {
given:
final Banner banner = new Banner(message: 'Spock is gr8!')
when:
banner.print()
then:
final List lines = capture.toString().tokenize(System.properties['line.separator'])
lines.first() == '*** Message ***'
lines.last() == ' Spock is gr8! '
}
}
/**
* Class under test. The print method
* uses println statements to display
* some message on the console.
*/
class Banner {
String message
void print() {
println ' Message '.center(15, '*')
println message.center(15)
}
}
Written with Spock-0.7-groovy-2.0.
