Using break, continue, return and throw inside of a finally block suppresses the
propagation of any unhandled Throwable thrown in the try or catch block.
This rule raises an issue when a jump statement (break, continue, return, throw) would force
control flow to leave a finally block.
Noncompliant code example
fun main() {
try {
doSomethingWhichThrowsException(5)
println("OK") // incorrect "OK" message is printed
} catch (e: RuntimeException) {
println("ERROR") // this message is not shown
}
try {
doSomethingThatAlsoThrowsException(5)
println("OK") // incorrect "OK" message is printed
} catch (e: RuntimeException) {
println("ERROR") // this message is not shown
}
}
fun doSomethingWhichThrowsException(q: Int) {
try {
throw RuntimeException()
} finally {
//...
if (someOtherCondition) {
return // Noncompliant - prevents the RuntimeException from being propagated
}
if (aLastConditionIsVerified) {
throw IllegalStateException() // Noncompliant - prevents the RuntimeException from being propagated
}
}
}
fun doSomethingThatAlsoThrowsException(q: Int) {
while (someConditionIsVerified) {
try {
throw RuntimeException()
} finally {
//...
if (someOtherCondition) {
continue // Noncompliant - prevents the RuntimeException from being propagated
}
break // Noncompliant - prevents the RuntimeException from being propagated
}
}
}
Compliant solution
fun main() {
try {
doSomethingWhichThrowsException()
println("OK")
} catch (e: RuntimeException) {
println("ERROR") // prints "ERROR" as expected
}
}
fun doSomethingWhichThrowsException(q: Int) {
try {
throw RuntimeException()
} finally {
while (someConditionIsVerified) {
//...
if (someOtherCondition) {
continue // Compliant - does not prevent the RuntimeException from being propagated
}
break // compliant - does not prevent the RuntimeException from being propagated
}
}
}
