fix wildcard rules are not reusable

[tbrockmeyer-a]

Summary:

Fixes #1358
Fixes #1341
(slightly different problems with the same root cause)

When using wildcard rules, it was not possible to reuse the same object that had the '*' key defined in it.

Cause:

Line 142: delete rules['*'] was modifying the argument to the function (which is sort of an anti-pattern for this kind of reason) and was causing subsequent uses of the same object to not have the wildcard rule for their own usage.

The issue that I was facing was that if you attempt to apply the middleware to a schema two or more times, it only has the wildcard rules for the first invocation. I've determined that the line above is the root cause of both issues.

Testing:

I have added a test (a copy of the wildcard test, but with a double usage to cause the error to occur). It was correctly failing prior to the fix, and began passing after the fix was added.

[tbrockmeyer-a]

Hi,

Because all of the checks have passed, I'd like to get a review at your earliest convenience so that we can get this merged. Thanks :D

[tbrockmeyer-a]

Hey, I'm pinging for visibility. Just need a review :)

[dimatill]

looks good to me, thank you @tbrockmeyer-a !