The when statement should be used only to clearly define some new branches in the control flow. As soon as a case clause contains too many statements this highly decreases the readability of the overall control flow statement. In such case, the content of the case clause should be extracted into a dedicated function.

Noncompliant Code Example

With the threshold set at 5:

when (myVariable) {
  0 -> {// Noncompliant: 6 lines till next case
    methodCall1("");
    methodCall2("");
    methodCall3("");
    methodCall4("");
    }
  1 -> {
    ...
  }
}

Compliant Solution

when (myVariable) {
  0 -> doSomething()
  1 -> {
    ...
  }
}
...
fun doSomething() {
    methodCall1("");
    methodCall2("");
    methodCall3("");
    methodCall4("");
}