Why is this an issue?
Having two cases in a match statement or two branches in an if chain with the same implementation is at best
duplicate code, and at worst a coding error. If the same logic is truly needed for both instances, then in an if chain they should be
combined, or for a match, one should fall through to the other.
Noncompliant code example
value match {
case 1 =>
doFirstThing
doSomething
case 2 =>
doSomethingDifferent
case 3 => // Noncompliant; duplicates case 1's implementation
doFirstThing
doSomething
case _ =>
doTheRest
}
if (a >= 0 && a < 10) {
doFirstThing
doTheThing
}
else if (a >= 10 && a < 20) {
doTheOtherThing
}
else if (a >= 20 && a < 50) {
doFirstThing
doTheThing // Noncompliant; duplicates first condition
}
else {
doTheRest
}
Exceptions
Blocks in an if chain that contain a single line of code are ignored, as are blocks in a match statement that contain a
single line of code.
if(a == 1) {
doSomething //no issue, usually this is done on purpose to increase the readability
} else if (a == 2) {
doSomethingElse
} else {
doSomething
}
But this exception does not apply to if chains without else-s, or to match-es without default clauses when
all branches have the same single line of code. In case of if chains with else-s, or of match-es with default
clauses, rule S3923 raises a bug.
if(a == 1) {
doSomething //Noncompliant, this might have been done on purpose but probably not
} else if (a == 2) {
doSomething
}
