source: imaps-frontend/node_modules/es-abstract/2017/RawBytesToNumber.js

'use strict';

var callBound = require('call-bind/callBound');

var $RangeError = require('es-errors/range');
var $TypeError = require('es-errors/type');

var $charAt = callBound('String.prototype.charAt');
var $reverse = callBound('Array.prototype.reverse');
var $slice = callBound('Array.prototype.slice');

var hasOwnProperty = require('./HasOwnProperty');
var IsArray = require('./IsArray');

var bytesAsFloat32 = require('../helpers/bytesAsFloat32');
var bytesAsFloat64 = require('../helpers/bytesAsFloat64');
var bytesAsInteger = require('../helpers/bytesAsInteger');
var every = require('../helpers/every');
var isByteValue = require('../helpers/isByteValue');

var keys = require('object-keys');

// https://262.ecma-international.org/8.0/#table-50
var TypeToSizes = {
        __proto__: null,
        Int8: 1,
        Uint8: 1,
        Uint8C: 1,
        Int16: 2,
        Uint16: 2,
        Int32: 4,
        Uint32: 4,
        Float32: 4,
        Float64: 8
};

// https://262.ecma-international.org/8.0/#sec-rawbytestonumber

module.exports = function RawBytesToNumber(type, rawBytes, isLittleEndian) {
        if (typeof type !== 'string' || !hasOwnProperty(TypeToSizes, type)) {
                throw new $TypeError('Assertion failed: `type` must be a TypedArray element type: ' + keys(TypeToSizes));
        }
        if (!IsArray(rawBytes) || !every(rawBytes, isByteValue)) {
                throw new $TypeError('Assertion failed: `rawBytes` must be an Array of bytes');
        }
        if (typeof isLittleEndian !== 'boolean') {
                throw new $TypeError('Assertion failed: `isLittleEndian` must be a Boolean');
        }

        var elementSize = TypeToSizes[type]; // step 1

        if (rawBytes.length !== elementSize) {
                // this assertion is not in the spec, but it'd be an editorial error if it were ever violated
                throw new $RangeError('Assertion failed: `rawBytes` must have a length of ' + elementSize + ' for type ' + type);
        }

        // eslint-disable-next-line no-param-reassign
        rawBytes = $slice(rawBytes, 0, elementSize);
        if (!isLittleEndian) {
                $reverse(rawBytes); // step 2
        }

        if (type === 'Float32') { // step 3
                return bytesAsFloat32(rawBytes);
        }

        if (type === 'Float64') { // step 4
                return bytesAsFloat64(rawBytes);
        }

        return bytesAsInteger(rawBytes, elementSize, $charAt(type, 0) === 'U', false);
};