Service Worker Scope

[FredXue]

if ('serviceWorker' in navigator) {
  navigator.serviceWorker.register('/sw-test/sw.js', { scope: '/sw-test/' }).then(function(reg) {
    // registration worked
    console.log('Registration succeeded. Scope is ' + reg.scope);
  }).catch(function(error) {
    // registration failed
    console.log('Registration failed with ' + error);
  });
};

We know the scope depends on the sw.js file's location, if the path of sw.js is '/sw-test/sw.js', then, the scope should be '/sw-test/'. So why do we need to define a scope attribute seperately?
I found the the scope can't be the parent directory of the SW path.

[FredXue]

I found my answer on #595