Based on https://github.com/prettier/prettier/pull/2676
* Thread `path` and `options` through helpers so we don't need to add `needsParens` onto the AST node anymore (mutation)
* Pull test call detection logic out into helper method so it can be re-used for arrow function parens
* Add arrow function parens option implementation (avoid/always)
* Don't break arrow function parens around (done) in test call
I've tried a lot of places where to fix this and this is the only one that gives correct results. This is likely not exhaustive but works for that use case. It's been reported twice in issues and I've seen it happen a few other times so we probably want to get it fixed.
Fixes#922Fixes#797
Stephen Scott