FYI: web-platform-tests are being written here:
https://github.com/w3c/web-platform-tests/pull/5515
For implementing, you should be able to test against these tests once they land (they will get imported into the directory third_party/LayoutTests/external/wpt/service-workers/service-worker)
Summary: Implement updateViaCache flag and cache imports only by default for service worker scripts (was: Implement useCache flag and no-cache by default for service worker scripts)
Comment 1 by n...@fb.com
, Dec 19 2016