unreachable_switch_case

This case is covered by the previous cases.

The analyzer produces this diagnostic when a case clause in a switch statement doesn't match anything because all of the matchable values are matched by an earlier case clause.

The following code produces this diagnostic because the value 1 was matched in the preceding case:

void f(int x) {
  switch (x) {
    case 1:
      print('one');
    case 1:
      print('two');
  }
}

Change one or both of the conflicting cases to match different values:

void f(int x) {
  switch (x) {
    case 1:
      print('one');
    case 2:
      print('two');
  }
}