- Optimize
Hash#rehashfor the common case, avoid calling$slicewhen no hash collision is present (#2571)
String#{r,l,}strip: Make them work like in MRI for non-breaking white-space (#2612)- Compat regression fix:
Hash#to_nshould return a JS object (#2613)
- Bump the ECMA version from 3 to 12 for ESLint (#2537)