mh-two-thousand-and-two
2024-04-12 7fc6dbf547b8899d949b67cdec36b96a7d1701c7
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'use strict';
 
var $TypeError = require('es-errors/type');
 
var IsFixedLengthArrayBuffer = require('./IsFixedLengthArrayBuffer');
var IsViewOutOfBounds = require('./IsViewOutOfBounds');
 
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-getviewbytelength
 
module.exports = function GetViewByteLength(viewRecord) {
    if (!isDataViewWithBufferWitnessRecord(viewRecord)) {
        throw new $TypeError('Assertion failed: `viewRecord` must be a DataView with Buffer Witness Record');
    }
 
    if (IsViewOutOfBounds(viewRecord)) {
        throw new $TypeError('Assertion failed: `viewRecord` is out of bounds'); // step 1
    }
 
    var view = viewRecord['[[Object]]']; // step 2
 
    var viewByteLength = dataViewByteLength(view); // view.[[ByteLength]]
    if (viewByteLength !== 'AUTO') {
        return viewByteLength; // step 3
    }
 
    if (IsFixedLengthArrayBuffer(dataViewBuffer(view))) {
        throw new $TypeError('Assertion failed: DataView’s ArrayBuffer is not fixed length'); // step 4
    }
 
    var byteOffset = dataViewByteOffset(view); // step 5
 
    var byteLength = viewRecord['[[CachedBufferByteLength]]']; // step 6
 
    if (byteLength === 'DETACHED') {
        throw new $TypeError('Assertion failed: DataView’s ArrayBuffer is detached'); // step 7
    }
 
    return byteLength - byteOffset; // step 8
};