Alibaba Terminal Technology

Aug 19, 2020 · Frontend Development

What’s New in ECMAScript? A Deep Dive into Stage 3‑4 TC39 Proposals

This article reviews the latest TC39 proposals advancing from Stage 3 to Stage 4—including Promise.any, AggregateError, WeakRefs, FinalizationRegistry, logical assignment operators, numeric literal separators, Intl.ListFormat, Intl.DateTimeFormat styles, iterator.item, Intl.Segmenter, Record & Tuple, JSON.parse source‑text access, await extensions, Array.prototype.unique, and resizable array buffers—explaining their goals, required thresholds, and providing concrete code examples.