Changelog

tc39/ecma262 · Oct 12–18, 2026 · 2 commits

Spec clarifications sharpen realm and typed array semantics

Editorially clarified prototype realm fallback and fixed typed array algorithm assumptions around buffer detachment and shrinking.

Realm-sensitive prototype fallback clarified

The spec now makes explicit that a constructor’s fallback prototype is taken from that constructor’s realm via [[Intrinsics]], and GetPrototypeFromConstructor returns immediately when prototype is already an object. This is mostly editorial, but it removes ambiguity around realm dependency.

Typed array filter and with corrected

The typed array algorithms now acknowledge that values may become undefined if user code detaches or shrinks the backing buffer during callback or coercion. The relevant TypedArraySetElement steps also now suppress user-code effects, fixing an overly strong assertion and bringing the spec in line with observable behavior.

Other misc changes

  • No other changes this week.