When Cache.put() is called with a Response, it consumes the response. If
the Response is used for any other purpose (such as satisfying the
original FetchEvent) it must be cloned first.
A bug exists in the mocks used for SW tests, where this condition is not
validated. The bodies of MockResponses can be utilized repeatedly without
erroring in the same way that a real browser would. This bug is fixed by
this commit, which causes tests for the freshness strategy of data caching
to start failing.
The cause of this failure is a second bug in the data caching code, where
the Response is not cloned prior to being passed to Cache.put(). This is
also fixed.
PR Close#19764
396c2417d9