Suporte ao ECMAScript 6 na Mozilla

ECMAScript 2015 é a próxima versão padronizada, chamada "ES.next". O espoço padrão pode ser encontrado na ECMA wiki. O primeiro projeto trabalhado baseado no ECMAScript 5.1, foi publicado em 12 de Julho, 2011 como "ES.next". Como o de 2014, ECMAScript 2015 já tem suas características fixas, determinadas, será terminado em 2015 e começará a ser inserido na documentação oficial em Março de 2015 (para ser finalizada em Junho de 2015).

O canal para feedbacks sobre padrões ECMAScript é o es-discuss.

The following features are already implemented in Firefox:

• Array iteration with for...of (Firefox 13)
• Array.from() (Firefox 32)
• Array.of() (Firefox 25)
• Array.prototype.fill() (Firefox 31)
• Array.prototype.find(), Array.prototype.findIndex() (Firefox 25)
• Array.prototype.entries(),
  Array.prototype.keys() (Firefox 28)
• Array.prototype.copyWithin() (Firefox 32)

• Map (Firefox 13)
  • Map iteration with for...of (Firefox 17)
  • Map.prototype.forEach() (Firefox 25)
  • Map.prototype.entries(),
    Map.prototype.keys(),
    Map.prototype.values() (Firefox 20)
  • Constructor argument: new Map(null) (Firefox 37)
  • Monkey-patched set() in Constructor (Firefox 37)
• Set (Firefox 13)
  • Set iteration with for...of (Firefox 17)
  • Set.prototype.forEach() (Firefox 25)
  • Set.prototype.entries(),
    Set.prototype.keys(),
    Set.prototype.values() (Firefox 24)
  • Constructor argument: new Set(null) (Firefox 37)
  • Monkey-patched add() in Constructor (Firefox 37)
• WeakMap (Firefox 6)
  • WeakMap.clear() (Firefox 20)
  • optional iterable argument in WeakMap constructor (Firefox 36)
  • Constructor argument: new WeakMap(null) (Firefox 37)
  • Monkey-patched set() in Constructor (Firefox 37)
• WeakSet (Firefox 34)
  • Constructor argument: new WeakSet(null) (Firefox 37)
  • Monkey-patched add() in Constructor (Firefox 37)

• Math.imul() (Firefox 20)
• Math.clz32() (Firefox 31)
• Math.fround() (Firefox 26)
• Math.log10(), Math.log2(), Math.log1p(), Math.expm1(), Math.cosh(), Math.sinh(), Math.tanh(), Math.acosh(), Math.asinh(), Math.atanh(), Math.hypot(), Math.trunc(), Math.sign(), Math.cbrt() (Firefox 25)

• Number.isNaN() (Firefox 16)
• Number.isFinite() (Firefox 16)
• Number.isInteger() (Firefox 16)
• Number.parseInt() (Firefox 25)
• Number.parseFloat() (Firefox 25)
• Number.EPSILON (Firefox 25)
• Number.MAX_SAFE_INTEGER, Number.MIN_SAFE_INTEGER (Firefox 31)
• Number.isSafeInteger() (Firefox 32)

• Object.is() (Firefox 22)
• Object.setPrototypeOf() (Firefox 31)
• Object.assign() (Firefox 34)
• Object.getOwnPropertySymbols() (Firefox 33)

• Promise (Firefox 24, enabled by default in Firefox 29)

• RegExp sticky (y) flag (Firefox 3)
• generic RegExp.prototype.toString (Firefox 39)

• String.fromCodePoint() (Firefox 29)
• String.prototype.codePointAt() (Firefox 29)
• String.prototype.startsWith(), String.prototype.endsWith() (Firefox 17)
• String.prototype.includes() (Firefox 17)
• String.prototype.repeat() (Firefox 24)
• String.prototype.normalize() (Firefox 31)
• String.raw() (Firefox 34)

• Symbol (Firefox 36)
• Symbol.iterator (Firefox 36)
• Symbol.for() - global Symbol registry (Firefox 36)
• Symbol.match (Firefox 40)

• Basic support (Firefox 39)
• extends support (Firefox 39)
• static method definitions (Firefox 39)

Typed arrays are specified as part of ECMAScript 6 and no longer in their own specification.

• ArrayBuffer
• DataView
• Int8Array
• Uint8Array
• Uint8ClampedArray
• Int16Array
• Uint16Array
• Int32Array
• Uint32Array
• Float32Array
• Float64Array

• Spread operator for arrays (Firefox 16)
  • use Symbol.iterator property (Firefox 36)
• Spread operator for function calls (Firefox 27)
  • use Symbol.iterator property (Firefox 36)

• for...of (Firefox 13)
  • works in terms of .iterator() and .next() (Firefox 17)
  • use "@@iterator" property (Firefox 27)
  • use Symbol.iterator property (Firefox 36)

• Rest parameters (Firefox 15)
• Default parameters (Firefox 15)
• Arrow functions (Firefox 22)
• Generator function (Firefox 26)
  • yield (Firefox 26)
  • yield* (Firefox 27)

• Binary and octal numeric literals (Firefox 25)
• Template strings (Firefox 34)
• Object initializer: shorthand property names (Firefox 33)
• Object initializer: computed property names (Firefox 34)
• Object initializer: shorthand method names (Firefox 34)

Os seguintes recursos estão (parcialmente) implementados n Firefox, mas foram introduzidos muito antes do ES2015 ou ainda estão sendo discutidos pela ECMA TC39 standards body.

• Legacy iterators and generators (JS 1.7, Firefox 2)
  • ES2015 iterators and generators implemented in Firefox 26+
• Destructuring assignment (JS 1.7, Firefox 2) (ES2015 compliance bug 950547)
• const (JS 1.5, Firefox 1.0) (ES2015 compliance bug 950547)
• let (JS 1.7, Firefox 2) (ES2015 compliance bug 950547)
• Proxy (Firefox 18) (ES2015 compliance bug 978228)

Os seguintes recursos estão no rascunho da especificação ECMAScript 6, mas ainda não foram implementados no firefox:

• Modules (bug 568953)
  • import syntax
  • export syntax
• Array.prototype.values() (bug 875433)
• Reflect (bug 987514)
• \u{nnnnnn} Unicode code point escapes (bug 320500)
• Well-known symbols
• RegExp "u" flag

• ECMAScript web site
• ECMAScript 2015 specification drafts
• Mozilla ES2015 tracking bug
• ECMAScript 2015 support across browsers