Re: [fetch] should navigation requests really be same-origin or no-cors? (#101)

I didn't know that the redirect flag of navigation request is "manual".
I think this will change the behavior of existing Service Workers.

Example:
- The server returns 302 redirect responses for these URLs:
  1. https://www.example.com/scope/in_scope_redirect -> https://www.example.com/scope/dir/destination
  2. https://www.example.com/scope/out_scope_redirect -> https://www.example.com/out_scope/destination

- The server returns 200 responses with the body "\<img src='./image.png'\>" for these URLs:
  1. https://www.example.com/scope/dir/destination
  2. https://www.example.com/out_scope/destination

- A serviceworker.js is registered for https://www.example.com/scope/
```javascript
  self.addEventListener('fetch', function(event) {
      if (event.request.url == 'https://www.example.com/scope/in_scope_sw_redirect') {
        event.respondWith(fetch('https://www.example.com/scope/dir/destination'));
      } else if (event.request.url == 'https://www.example.com/scope/out_scope_sw_redirect') {
        event.respondWith(fetch('https://www.example.com/out_scope/destination'));
      } else {
        event.respondWith(fetch(event.request));
      }
    });
```

- The current behavior in Chrome:
 1. When the user opens "https://www.example.com/scope/in_scope_redirect".
    The URL bar of the pege is "https://www.example.com/scope/in_scope_redirect".
    The page sends a fetch request "https://www.example.com/scope/image.png" via the Service Worker.

 2. When the user opens "https://www.example.com/scope/out_scope_redirect".
    The URL bar of the pege is "https://www.example.com/scope/out_scope_redirect".
    The page sends a fetch request "https://www.example.com/scope/image.png" via the Service Worker.

 3. When the user opens "https://www.example.com/scope/in_scope_sw_redirect".
    The URL bar of the pege is "https://www.example.com/scope/in_scope_sw_redirect".
    The page sends a fetch request "https://www.example.com/scope/image.png" via the Service Worker.

 4. When the user opens "https://www.example.com/scope/out_scope_sw_redirect".
    The URL bar of the pege is "https://www.example.com/scope/out_scope_sw_redirect".
    The page sends a fetch request "https://www.example.com/scope/image.png" via the Service Worker.


- If the navigation requests of redirect flag is "manual".
 1. When the user opens "https://www.example.com/scope/in_scope_redirect".
    fetch(event.request) returns a "opaqueredirect" response which points to "https://www.example.com/scope/dir/destination".
    The URL bar of the pege is changed to "https://www.example.com/scope/dir/destination".
    The page sends a navigation request "https://www.example.com/scope/dir/destination" via the Service Worker.
    The page sends a fetch request "https://www.example.com/scope/dir/image.png" via the Service Worker.

 2. When the user opens "https://www.example.com/scope/out_scope_redirect".
    fetch(event.request) returns a "opaqueredirect" response which points to "https://www.example.com/out_scope/destination".
    The URL bar of the pege is changed to "https://www.example.com/out_scope/destination".
    The page will not be controlled by the Service Worker.
    The page sends a navigation request "https://www.example.com/out_scope/destination" which is not handled by the Service Worker.
    The page sends a fetch request "https://www.example.com/out_scope/image.png" which is not handled by the Service Worker.

 3. When the user opens "https://www.example.com/scope/in_scope_sw_redirect".
    The URL bar of the pege is "https://www.example.com/scope/in_scope_sw_redirect".
    The page sends a fetch request "https://www.example.com/scope/image.png" via the Service Worker.

 4. When the user opens "https://www.example.com/scope/out_scope_sw_redirect".
    The URL bar of the pege is "https://www.example.com/scope/out_scope_sw_redirect".
    The page sends a fetch request "https://www.example.com/scope/image.png" via the Service Worker.


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Reply to this email directly or view it on GitHub:
https://github.com/whatwg/fetch/issues/101#issuecomment-128245354