support proper merging of nested conditionals

[wyattisimo]

Currently, nested option blocks containing conditionals like this:

with_options(:if => {:awesome => true}) do
  with_options(:if => {:less_awesome => false}) do
    expose :awesome_thing
  end
end

will produce an exposure that reflects only the innermost conditions:

{:if => {:less_awesome => false}}

To me, this is unexpected behavior. I would expect the following exposure from the code above:

{:if => {:awesome => true, :less_awesome => false}}

This pull request enables proper merging of nested conditionals. All Hash conditions are merged into a single hash. Proc and Symbol conditions are pushed to a special "extras" array. For evaluation, the hash is added to the extras array and all the conditions are logically ANDed together.

[dblock]

This is great. Could you please update CHANGELOG, too? (Use git --amend).

[dblock]

I don't think you want to merge! (with a bang) into the final result, inject is supposed to return this, no?

[wyattisimo]

I dunno, it was like that when I got here :)

The bang isn't hurting anything, but you're right, it's not needed.

[wyattisimo]

Questions? Comments? Cheap shots?

[dblock]

This is creative, but a little unorthodox. You should just make this a private method, something like merge_options.

[dblock]

Merge parameters aren't really old or new, they are more lhs and rhs (left hand side / right hand side), no?

[wyattisimo]

I suppose old could be more appropriately named existing as it is the value of the key in the existing hash accepting the merge, and new is the value of the key in the new hash being merged in. That makes sense to my brain, but I guess lhs and rhs work just as well, since lhs receives the merge--reminds me of an SQL JOIN. I'll change it if you think lhs and rhs are more clear.

[dblock]

I made some minor comments. You also still need to update CHANGELOG, please.

Thanks for being patient with my nitpicking.

[wyattisimo]

@dblock I updated CHANGELOG and moved all the merge logic into a private method. Let me know if you want to use lhs and rhs in that merge proc.

[dblock]

Great, merging.