With the following code, the no-fallthrough rule correctly warns about the missing break statement.

let foo = 'bar';

switch (foo) {
  case 'bar':
    console.log('Reached matching case.');

  default:
    console.log('Reached default case.');
}

Expected a "break" statement before "default"

However, when braces surround the case statements, no-fallthrough fails to report the problem, even though all cases are indeed executed.

let foo = 'bar';

switch (foo) {
  case 'bar': {
    console.log('Reached matching case.');
  }

  default: {
    console.log('Reached default case.');
  }
}

Using ESLint v1.10.3.