diff options
Diffstat (limited to 'node_modules/es-abstract/2018/ArraySetLength.js')
-rw-r--r-- | node_modules/es-abstract/2018/ArraySetLength.js | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/node_modules/es-abstract/2018/ArraySetLength.js b/node_modules/es-abstract/2018/ArraySetLength.js new file mode 100644 index 000000000..c9134c6e6 --- /dev/null +++ b/node_modules/es-abstract/2018/ArraySetLength.js @@ -0,0 +1,85 @@ +'use strict'; + +var GetIntrinsic = require('../GetIntrinsic'); + +var $RangeError = GetIntrinsic('%RangeError%'); +var $TypeError = GetIntrinsic('%TypeError%'); + +var assign = require('object.assign'); + +var isPropertyDescriptor = require('../helpers/isPropertyDescriptor'); + +var IsArray = require('./IsArray'); +var IsAccessorDescriptor = require('./IsAccessorDescriptor'); +var IsDataDescriptor = require('./IsDataDescriptor'); +var OrdinaryDefineOwnProperty = require('./OrdinaryDefineOwnProperty'); +var OrdinaryGetOwnProperty = require('./OrdinaryGetOwnProperty'); +var ToNumber = require('./ToNumber'); +var ToString = require('./ToString'); +var ToUint32 = require('./ToUint32'); +var Type = require('./Type'); + +// https://www.ecma-international.org/ecma-262/6.0/#sec-arraysetlength + +// eslint-disable-next-line max-statements, max-lines-per-function +module.exports = function ArraySetLength(A, Desc) { + if (!IsArray(A)) { + throw new $TypeError('Assertion failed: A must be an Array'); + } + if (!isPropertyDescriptor({ + Type: Type, + IsDataDescriptor: IsDataDescriptor, + IsAccessorDescriptor: IsAccessorDescriptor + }, Desc)) { + throw new $TypeError('Assertion failed: Desc must be a Property Descriptor'); + } + if (!('[[Value]]' in Desc)) { + return OrdinaryDefineOwnProperty(A, 'length', Desc); + } + var newLenDesc = assign({}, Desc); + var newLen = ToUint32(Desc['[[Value]]']); + var numberLen = ToNumber(Desc['[[Value]]']); + if (newLen !== numberLen) { + throw new $RangeError('Invalid array length'); + } + newLenDesc['[[Value]]'] = newLen; + var oldLenDesc = OrdinaryGetOwnProperty(A, 'length'); + if (!IsDataDescriptor(oldLenDesc)) { + throw new $TypeError('Assertion failed: an array had a non-data descriptor on `length`'); + } + var oldLen = oldLenDesc['[[Value]]']; + if (newLen >= oldLen) { + return OrdinaryDefineOwnProperty(A, 'length', newLenDesc); + } + if (!oldLenDesc['[[Writable]]']) { + return false; + } + var newWritable; + if (!('[[Writable]]' in newLenDesc) || newLenDesc['[[Writable]]']) { + newWritable = true; + } else { + newWritable = false; + newLenDesc['[[Writable]]'] = true; + } + var succeeded = OrdinaryDefineOwnProperty(A, 'length', newLenDesc); + if (!succeeded) { + return false; + } + while (newLen < oldLen) { + oldLen -= 1; + // eslint-disable-next-line no-param-reassign + var deleteSucceeded = delete A[ToString(oldLen)]; + if (!deleteSucceeded) { + newLenDesc['[[Value]]'] = oldLen + 1; + if (!newWritable) { + newLenDesc['[[Writable]]'] = false; + OrdinaryDefineOwnProperty(A, 'length', newLenDesc); + return false; + } + } + } + if (!newWritable) { + return OrdinaryDefineOwnProperty(A, 'length', { '[[Writable]]': false }); + } + return true; +}; |