## Proposed language features # # This project accepts tests for language proposals that have reached stage 3 # in TC39's standardization process. Those tests should be annotated with a # dedicated feature flag so that consumers may more easily omit them as # necessary. # # https://github.com/tc39/process-document # Missing checks in Proxy internal methods # https://github.com/tc39/ecma262/pull/666 proxy-missing-checks # Promise.allSettled # https://github.com/tc39/proposal-promise-allSettled Promise.allSettled # Hashbang Grammar # https://github.com/tc39/proposal-hashbang hashbang # Object.fromEntries # https://github.com/tc39/proposal-object-from-entries Object.fromEntries # BigInt # https://github.com/tc39/proposal-bigint BigInt # Class Fields # https://github.com/tc39/proposal-class-fields class-fields-public class-fields-private # Class Static Fields & Methods # https://github.com/tc39/proposal-static-class-features/ class-static-fields-public class-static-fields-private class-static-methods-private # Class Private methods and getter/setters # https://github.com/tc39/proposal-private-methods class-methods-private # Dynamic Import # https://github.com/tc39/proposal-dynamic-import dynamic-import # Array.prototype.flat and Array.prototype.flatMap # https://github.com/tc39/proposal-flatMap Array.prototype.flat Array.prototype.flatMap # String Trimming # https://github.com/tc39/proposal-string-left-right-trim # Includes all tests for: # String.prototype.{trimStart, trimEnd, trimLeft, trimRight} string-trimming String.prototype.trimEnd String.prototype.trimStart # Numeric Separator Literal # https://github.com/tc39/proposal-numeric-separator numeric-separator-literal # String.prototype.matchAll # https://github.com/tc39/proposal-string-matchall String.prototype.matchAll Symbol.matchAll # Symbol.prototype.description # https://github.com/tc39/proposal-symbol-description Symbol.prototype.description # Well-formed JSON.stringify # https://github.com/tc39/proposal-well-formed-stringify well-formed-json-stringify # Intl.ListFormat # https://github.com/tc39/proposal-intl-list-format Intl.ListFormat # Intl.Locale # https://github.com/tc39/proposal-intl-locale Intl.Locale # Intl.Locale Info # https://github.com/tc39/proposal-intl-locale-info Intl.Locale-info # Intl.RelativeTimeFormat # https://github.com/tc39/proposal-intl-relative-time Intl.RelativeTimeFormat # Intl.Segmenter # https://github.com/tc39/proposal-intl-segmenter Intl.Segmenter # Intl.NumberFormat unified proposal # https://github.com/sffc/proposal-unified-intl-numberformat Intl.NumberFormat-unified # Intl.DateTimeFormat: dateStyle and timeStyle options # https://github.com/tc39/proposal-intl-datetime-style Intl.DateTimeFormat-datetimestyle # Intl.DateTimeFormat: formatRange and formatRangeToParts functions # https://github.com/tc39/proposal-intl-DateTimeFormat-formatRange Intl.DateTimeFormat-formatRange # Intl.DateTimeFormat: add 'dayPeriod' option # https://github.com/tc39/ecma402/pull/346 Intl.DateTimeFormat-dayPeriod # Intl.DateTimeFormat: add 'quarter' option # https://github.com/tc39/ecma402/pull/346 Intl.DateTimeFormat-quarter # Intl.DateTimeFormat: add 'fractionalSecondDigits' option # https://github.com/tc39/ecma402/pull/347 Intl.DateTimeFormat-fractionalSecondDigits # Intl "normative optional" # https://tc39.es/ecma402/#legacy-constructor intl-normative-optional # Intl "Intl.DisplayNames v2" # https://github.com/tc39/intl-displaynames-v2 Intl.DisplayNames-v2 # Intl "Extend TimeZoneName Option Proposal" # https://github.com/tc39/proposal-intl-extend-timezonename Intl.DateTimeFormat-extend-timezonename # Global # https://github.com/tc39/proposal-global globalThis # `export * as namespace from module` # https://github.com/tc39/ecma262/pull/1174 export-star-as-namespace-from-module # import.meta # https://github.com/tc39/proposal-import-meta import.meta # WeakRef # https://github.com/tc39/proposal-weakref WeakRef FinalizationRegistry # FinalizationRegistry#cleanupSome # link pending FinalizationRegistry.prototype.cleanupSome cleanupSome # Optional Chaining # https://github.com/tc39/proposal-optional-chaining optional-chaining # Top Level Await # https://github.com/tc39/proposal-top-level-await top-level-await # RegExp Match Array Indices # https://github.com/tc39/proposal-regexp-match-indices regexp-match-indices # Nullish Coalesce Expression # https://github.com/tc39/proposal-nullish-coalescing coalesce-expression # Intl.DisplayNames # https://github.com/tc39-transfer/proposal-intl-displaynames Intl.DisplayNames # Promise.any # https://github.com/tc39/proposal-promise-any Promise.any AggregateError # String.prototype.replaceAll # https://github.com/tc39/proposal-string-replaceall String.prototype.replaceAll # Enumeration order for for-in # https://github.com/tc39/proposal-for-in-order for-in-order # Legacy RegExp features # https://github.com/tc39/proposal-regexp-legacy-features legacy-regexp # Logical Assignment Operators # https://github.com/tc39/proposal-logical-assignment logical-assignment-operators # Atomics.waitAsync # https://github.com/tc39/proposal-atomics-wait-async Atomics.waitAsync # Item Method # https://github.com/tc39/proposal-item-method Array.prototype.at String.prototype.at TypedArray.prototype.at # Arbitrary module namespace names # https://github.com/tc39/ecma262/pull/2154 arbitrary-module-namespace-names # Align detached buffer semantics with web reality # https://github.com/tc39/ecma262/pull/2164 align-detached-buffer-semantics-with-web-reality # Object.hasOwn # https://github.com/tc39/proposal-accessible-object-hasownproperty Object.hasOwn # Class static initialization blocks # https://github.com/tc39/proposal-class-static-block class-static-block ## Standard language features # # Language features that have been included in a published version of the # ECMA-262 specification. These flags are largely maintained for historical # reasons, though their use for relatively new features (i.e. prior to # availability across major implementations) is appreciated. ArrayBuffer Array.prototype.values arrow-function async-iteration async-functions Atomics caller class computed-property-names const cross-realm DataView DataView.prototype.getFloat32 DataView.prototype.getFloat64 DataView.prototype.getInt16 DataView.prototype.getInt32 DataView.prototype.getInt8 DataView.prototype.getUint16 DataView.prototype.getUint32 DataView.prototype.setUint8 default-parameters destructuring-assignment destructuring-binding for-of Float32Array Float64Array generators Int8Array Int16Array Int32Array json-superset let Map new.target object-rest object-spread Object.is optional-catch-binding Promise Promise.prototype.finally Proxy Reflect Reflect.construct Reflect.set Reflect.setPrototypeOf regexp-dotall regexp-lookbehind regexp-named-groups regexp-unicode-property-escapes rest-parameters Set SharedArrayBuffer String.fromCodePoint String.prototype.endsWith String.prototype.includes super Symbol Symbol.asyncIterator Symbol.hasInstance Symbol.isConcatSpreadable Symbol.iterator Symbol.match Symbol.replace Symbol.search Symbol.species Symbol.split Symbol.toPrimitive Symbol.toStringTag Symbol.unscopables tail-call-optimization template TypedArray u180e Uint8Array Uint16Array Uint32Array Uint8ClampedArray WeakMap WeakSet __proto__ __getter__ __setter__ ## Test-Harness Features # # The rare cases where testing language functionality requires non-standard # language features, exposed through global-environment functions on the $262 # object, go here. IsHTMLDDA host-gc-required # Ergonomic brand checks for Private Fields # https://github.com/tc39/proposal-private-fields-in-in class-fields-private-in # Error cause # https://github.com/tc39/proposal-error-cause error-cause # Import Assertions # https://github.com/tc39/proposal-import-assertions/ import-assertions # JSON modules # https://github.com/tc39/proposal-json-modules json-modules # Resizable Arraybuffer # https://github.com/tc39/proposal-resizablearraybuffer resizable-arraybuffer # Temporal # https://github.com/tc39/proposal-temporal Temporal