1062075 - Throw for ES6 built-in constructors called without `new`

Status: RESOLVED FIXED

(Core :: JavaScript: Standard Library, defect)

Description

[ziyunfei]

js> Map()
({}) // http://people.mozilla.org/~jorendorff/es6-draft.html#sec-map-iterable steps 1-2
js> Set()
({}) // http://people.mozilla.org/~jorendorff/es6-draft.html#sec-set-iterable steps 1-2
js> WeakMap()
({}) // http://people.mozilla.org/~jorendorff/es6-draft.html#sec-weakmap-iterable steps 1-2
js> ArrayBuffer()
({}) // http://people.mozilla.org/~jorendorff/es6-draft.html#sec-arraybuffer-length steps 1-2
js> DataView(ArrayBuffer())
({}) // http://people.mozilla.org/~jorendorff/es6-draft.html#sec-dataview-buffer-byteoffset-bytelength steps 1-2

According to the spec, these should all throw an exception like Promise does

devtools>Promise()
TypeError: Constructor Promise requires 'new'

The discussion thread is here: http://esdiscuss.org/topic/promise-vs-new-promise

Comment 1

[Till Schneidereit [:till]]

There is bug 980945 for typed arrays specifically, but we don't yet have a tracking bug for this. Turning this into one.

Comment 2

[Tom S [:evilpie]]

I think we are done here.

Comment 3

[Kohei Yoshino [:kohei]]

Added a note to https://www.fxsitecompat.com/en-US/docs/2015/calling-typed-array-constructors-without-new-will-throw/