The one readily available on search: https://github.com/petkaantonov/bluebird/wiki/Optimization-killers#2-unsupported-syntax https://github.com/petkaantonov/blu

The one readily available on search: https://github.com/petkaantonov/bluebird/wiki/Optimization-killers#2-unsupported-syntax https://github.com/petkaantonov/bluebird/wiki/Optimization-k... Otherwise the fact that engines bailout on optimizing ES6 features was kind of common knowledge when engines started to implement them.