Conditional Invalidation Option

[blimmer]

What if there were an option to only invalidate files if they've changed?

For context, the only time we really have to manually invalidate our cache is when we update our apple-app-site-association file (which is pretty rare). If I understand the code / documentation correctly, it looks like this would trigger an invalidation every time we deploy.

Thoughts?

[kpfefferle]

This is an interesting idea and one not considered in the initial implementation since the primary use case invalidates index.html which changes every time a change to a standard Ember application is deployed. I'd certainly be open to a PR that would check for changes, but I'd probably want it to be an opt-in option since I would expect that comparing the currently deployed file on S3 to the newly built version would necessarily add quite a bit of complexity.