Add failing test case for rewriting the same URL multiple times

[grayt0r]

This PR adds a failing test case for rewriting the same URL multiple times within the same file.

Believe this demonstrates #39, as well as possibly the root cause of ember-cli/broccoli-asset-rev#99.

[rickharrison]

Thanks for submitting this failing test. I've pinpointed the reason for this behind the additions in #35. The unfortunate part is I do not know how to fix this. Using a null customHash is very difficult, because we use a regex to find and loop through all the asset paths in your code base. When you change the path of the asset with a fingerprint, that particular regex will not match anymore because it is changed. However, when you don't add a hash (customHash: null), it will continue to match the number of times you have this asset. In the test, the asset appears 3 times, which is why assets/assets/assets/ is repeated 3 times.

I am beginning to think that we are trying to support too many use cases in this module. The pairing of asset-rev/rewrite is to fingerprint assets. By definition, when using a null custom hash, you are not fingerprinting the assets. I think it may be best to write a tool solely for the use case of prepending a CDN to all of your assets. Perhaps, it might help me to understand the use case. I have never shipped code in production that needs to be off a CDN, but needs to not have a hash associated with it. Why do you need to do this?

@rwjblue @stefanpenner I'd love to hear your thoughts on deprecating this particular use case and building another tool strictly for prepending to an asset and not fingerprinting.

[typeoneerror]

@rickharrison Can't speak for others, but my use case for why this is needed is when I'm running the application locally and need to prepend "http://localhost:4200/" because I'm loading the ember template in a Rails application and serving at different subdomains (sub1.server.dev:3000, sub2.server.dev:3000, for example). In this case, I don't want fingerprinting because it takes 20-30 seconds on each build. With customHash=null, I get the prepend feature (builds in about 5-8 seconds instead!) but the URLS end up as /assets/assets/assets. I agree that this use case is pretty edge, but it does seem like this is a recurring need for multiple ember devs. Happy to hear about a different solution that avoids this!

[typeoneerror]

FYI, this is still an issue, but I found out today (after stumbling into my original bug report in 2016) that if you pass literally anything else to customHash but null, it works. So I just did:

customHash: 'file'

Now you effectively have a fixed file name but prepend still works.

I don't expect this bug to ever be fixed since it's still around, but this is a good workaround as this is a bit of an edge case (though not that much of an edge case seeing that this is the third project I've run into it on ;))