diff options
Diffstat (limited to 'src/node_modules/es-abstract/2016/ArrayCreate.js')
-rw-r--r-- | src/node_modules/es-abstract/2016/ArrayCreate.js | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/src/node_modules/es-abstract/2016/ArrayCreate.js b/src/node_modules/es-abstract/2016/ArrayCreate.js new file mode 100644 index 0000000..fc9a7cf --- /dev/null +++ b/src/node_modules/es-abstract/2016/ArrayCreate.js @@ -0,0 +1,53 @@ +'use strict'; + +var GetIntrinsic = require('../GetIntrinsic'); + +var $ArrayPrototype = GetIntrinsic('%Array.prototype%'); +var $RangeError = GetIntrinsic('%RangeError%'); +var $SyntaxError = GetIntrinsic('%SyntaxError%'); +var $TypeError = GetIntrinsic('%TypeError%'); + +var IsInteger = require('./IsInteger'); + +var MAX_ARRAY_LENGTH = Math.pow(2, 32) - 1; + +var $setProto = GetIntrinsic('%Object.setPrototypeOf%', true) || ( + // eslint-disable-next-line no-proto, no-negated-condition + [].__proto__ !== $ArrayPrototype + ? null + : function (O, proto) { + O.__proto__ = proto; // eslint-disable-line no-proto, no-param-reassign + return O; + } +); + +// https://www.ecma-international.org/ecma-262/6.0/#sec-arraycreate + +module.exports = function ArrayCreate(length) { + if (!IsInteger(length) || length < 0) { + throw new $TypeError('Assertion failed: `length` must be an integer Number >= 0'); + } + if (length > MAX_ARRAY_LENGTH) { + throw new $RangeError('length is greater than (2**32 - 1)'); + } + var proto = arguments.length > 1 ? arguments[1] : $ArrayPrototype; + var A = []; // steps 5 - 7, and 9 + if (proto !== $ArrayPrototype) { // step 8 + if (!$setProto) { + throw new $SyntaxError('ArrayCreate: a `proto` argument that is not `Array.prototype` is not supported in an environment that does not support setting the [[Prototype]]'); + } + $setProto(A, proto); + } + if (length !== 0) { // bypasses the need for step 2 + A.length = length; + } + /* step 10, the above as a shortcut for the below + OrdinaryDefineOwnProperty(A, 'length', { + '[[Configurable]]': false, + '[[Enumerable]]': false, + '[[Value]]': length, + '[[Writable]]': true + }); + */ + return A; +}; |