Having all branches in a case or if chain with the same implementation is an error. Either a copy-paste error was made and something different should be executed, or there shouldn't be a case/if chain at all.

Noncompliant Code Example

if b == 0  # Noncompliant
  doOneMoreThing()
else
  doOneMoreThing()
end

b = a > 12 ? 4 : 4;  # Noncompliant

case i  # Noncompliant
  when 1
    doSomething()
  when 2
    doSomething()
  when 3
    doSomething()
  else
    doSomething()
end

Exceptions

This rule does not apply to if chains or case-es without else-s.

if b == 0 # no issue, this could have been done on purpose to make the code more readable
  doSomething()
elsif b == 1
  doSomething()
end