'use strict'; var $TypeError = require('es-errors/type'); var IsDetachedBuffer = require('./IsDetachedBuffer'); var isDataViewWithBufferWitnessRecord = require('../helpers/records/data-view-with-buffer-witness-record'); var dataViewBuffer = require('data-view-buffer'); var dataViewByteLength = require('data-view-byte-length'); var dataViewByteOffset = require('data-view-byte-offset'); // https://262.ecma-international.org/15.0/#sec-isviewoutofbounds module.exports = function IsViewOutOfBounds(viewRecord) { if (!isDataViewWithBufferWitnessRecord(viewRecord)) { throw new $TypeError('Assertion failed: `viewRecord` must be a DataView With Buffer Witness Record'); } var view = viewRecord['[[Object]]']; // step 1 var bufferByteLength = viewRecord['[[CachedBufferByteLength]]']; // step 2 if (IsDetachedBuffer(dataViewBuffer(view)) !== (bufferByteLength === 'DETACHED')) { // step 3 throw new $TypeError('Assertion failed: `IsDetachedBuffer(dataViewBuffer(view))` must be true if and only if `bufferByteLength === ~DETACHED~'); } if (bufferByteLength === 'DETACHED') { return true; // step 4 } var byteOffsetStart = dataViewByteOffset(view); // step 5 var dvByteLength = dataViewByteLength(view); var byteOffsetEnd = dvByteLength === 'AUTO' ? bufferByteLength : byteOffsetStart + dvByteLength; // steps 6 - 7 if (byteOffsetStart > bufferByteLength || byteOffsetEnd > bufferByteLength) { return true; // step 8 } // 9. NOTE: 0-length DataViews are not considered out-of-bounds. return false; // step 10 };