Propagate TestSecurityContextHolder to SecurityContextHolder

[marcusdacoregio]

Create SecurityMockMvcResultHandlers to define security related MockMvc ResultHandlers
Create a method to allow copying the SecurityContext from the TestSecurityContextHolder to SecurityContextHolder

Closes gh-9565

[marcusdacoregio]

A new section in the documentation named SecurityMockMvcResultHandlers should be added to show this new feature.

[jzheaux]

Nice, @marcusdacoregio! Please see my feedback inline.

[marcusdacoregio]

Thank you very much for your review @jzheaux.

I've updated the PR based on your suggestions.

[rwinch]

Thanks for the PR! I've left feedback inline.

[rwinch]

I'd like a name that is a bit more explicit as to what is happening. Perhaps propagateTestSecurityContext? I think a better name could be found that my suggestion, but the idea is it should convey what is being done.

[jzheaux]

"propagate", "retain" and "keep" all seem to imply that it will be retained across multiple MockMvc invocations in the same test. Would that be the case? If this isn't a concern, then my favorite among these options is "retain". If it is a concern, then I still like "export" best.

Looking more deeply into the support, I see that there is a request post-processor static method called testSecurityContext(). In that case, "xyzTestSecurityContext" does seem more consistent.

[marcusdacoregio]

I think we should indeed mention TestSecurityContext in the name. It would be explicit if we do exportTestSecurityContext, since it gives the idea of the TestSecurityContext being exported somewhere, and this also gives the opportunity to extend it to exportTestSecurityContext(Consumer<SecurityContext> exportTo).

If we use names like save, propagate, preserve, all of them give the idea that the TestSecurityContextHolder will not be cleared out.

[rwinch]

"propagate", "retain" and "keep" all seem to imply that it will be retained across multiple MockMvc invocations in the same test. Would that be the case?

I am not a fan of save, retain, preserve, or keep because I interpret these to mean that the TestSecurityContextHolder will not be changed which is true regardless of the ResultHandler being used. The behavior is copy/export/propagate the TestSecurityContextHolder into the SecurityContext.

[marcusdacoregio]

Thanks @rwinch. I've updated the PR based on your suggestions.

The method's name has been changed to exportTestSecurityContext.