ECMAScript - Proposals for Future Editions

Per https://github.com/tc39/ecma262

script - unit tests

Stage 3

See also:

Promise prototype: finally() ref
Array prototype: flatten() and flatMap() ref

Stage 2

String prototype: trimStart(), trimEnd() (and trimLeft(), trimRight() aliases) ref
String.prototype: matchAll() ref

Stage 1

Math extensions: clamp(), scale(), radians(), degrees(), RAD_PER_DEG, DEG_PER_RAD ref
Set/Map/WeakSet/WeakMap .of() and .from() ref
Promise: try() ref
String prototype: replaceAll() ref
String prototype: codePoints() ref
Math: signbit() ref

See also:

Intl.Segmenter

Stage 0

String.prototype.at() ref

See also:

Int64

Obsolete/Abandoned Proposals

Number: compare()
Array prototype: pushAll()
Reflection: Object.getPropertyDescriptor(o), Object.getPropertyNames(o)
Math: denormz(), fdenormz()
64-bit Math: imulh(), umulh(), iaddh(), isubh() ref