Rebased since I was out of date.

Added some more spec coverage to ensure state is reset at the end.

I'm realizing we should probably do the same for YAML::Any

Okay so the real proper Object Oriented Approved way to do this is to modify Array#inspect and Hash#inspect to use double recursion.

Essentially this would mean defining something like:

class Object
  def inspect_recursive(io : IO) : Nil
    inspect(io)
  end
end

and having all recursive calls to #inspect such as in Array and Hash use this indirect method instead:

class Array
  def inspect(io : IO) : Nil
    # ...
    join io, ", ", &.inspect_recursive(io)
  end
end

Then classes like JSON::Any could specify separate behaviour on the two.

This is a much deeper-reaching change though, so I'd like thoughts on whether this stack-flag hack is preferable to that.

I had a thought that we could use #to_s as a bit of a hack:

class Any
  def inspect(io : IO)
    io << "JSON::Any("
    to_s(io)
    io << ')'
  end

  def to_s(io : IO)
    @raw.to_s(io)
  end
end

but unfortunately Array#to_s calls into #inspect on its elements, which I suppose makes sense?

rebased.

I presume for the YAML case we want this to show up in error messages as well?

      expect_raises(KeyError, %(Missing hash key: YAML::Any(nil))) do
        any[YAML::Any.new(nil)]
      end

Hm, not sure about the error in YAML::Any[].
It's probably not necessary to spell out the wrapper type because x and YAML::Any.new(x) behave identical in this method. It doesn't matter whether the value is raw or wrapped.

We're still missing the same for YAML::Any. It feels a bit weird to release this only for JSON::Any, but it's impossible to merge in time for the new release. We could consider pulling this change and re-introducing it afterwards, together with YAML::Any.

It should be fine to have only this in 1.18 and follow up with YAML::Any in 1.19, though.

It should be fine to have only this in 1.18 and follow up with YAML::Any in 1.19, though.

👍