bufferToggle: fixes and tests

[staltz]

No description provided.

[benlesh]

merged with 949fa31 ... thanks @staltz ..

Looking at that bit with context, I wonder if it would have been better to have a sub class of Subscription that carried the buffer with it and managed semantics around buffer size and completion... Dunno. I think your solution is fine.

[staltz]

I wonder if it would have been better to have a sub class of Subscription that carried the buffer with it

That didn't occur to me when I was fixing, you mean it would be better in performance or in elegance? I just tried to do minimal changes in order to get tests passing.

[benlesh]

I'd be curious about either, honestly. But it's not a big deal