YAML file gets completely re-ordered and re-written
I was just navigating with { } when I saw the empty lines were all gone. Not good.
Holy shit no it actually raw re-orders and re-writes the whole damn file!
It also nixes any aliases one could have in there.
As for the solution, just took a dive in Psych, it's not pretty. Realistically the thing we could do is parse the YAML, figure out a place to put the new key, open up the Psych AST, insert the key, wrap it up, dump YAML. With the possible option of putting a new line for every mapping that has more than 10 keys.
If you do this, would be nice to have it as a separate gem, as it's a frequently requested feature in i18n-tasks.