ECMAScript roadmap: New JavaScript features for 2019

ECMAScript 2019, the planned next version of the specification serving as the basis of JavaScript, is moving forward. The first two proposals havw reached the “finished” stage thus far.

These proposals include:

• Symbol.prototype.description, an accessor property whose set accessor is undefined. Its get accessor function performs steps including: Let s be this value, let sym be ? thisSymbolValue(s), and return sym.[[Description]]. The goal of this feature is to expose the [[Description]] internal slot of a symbol directly instead of only indirectly through Symbol.prototype.toString.
• Changes to Function.prototype.toString. Revisions have been proposed such as implementations not being required to retain source text for all functions defined using ECMAScript code.